BAEL-1996 (#5507)

* [BAEL-1996] WIP - Initial import

* [BAEL-1996] Apply formatting rules

* [BAEL-1996] Import UAA modules

* [BAEL-1996] New directory structure

jhipster/jhipster-uaa/gateway/.editorconfig

@@ -0,0 +1,24 @@
+# EditorConfig helps developers define and maintain consistent
+# coding styles between different editors and IDEs
+# editorconfig.org
+
+root = true
+
+[*]
+
+# Change these settings to your own preference
+indent_style = space
+indent_size = 4
+
+# We recommend you to keep these unchanged
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[{package,bower}.json]
+indent_style = space
+indent_size = 2

jhipster/jhipster-uaa/gateway/.gitattributes

@@ -0,0 +1,149 @@
+# This file is inspired by https://github.com/alexkaratarakis/gitattributes
+#
+# Auto detect text files and perform LF normalization
+# http://davidlaing.com/2012/09/19/customise-your-gitattributes-to-become-a-git-ninja/
+* text=auto
+
+# The above will handle all files NOT found below
+# These files are text and should be normalized (Convert crlf => lf)
+
+*.bat           text eol=crlf
+*.coffee        text
+*.css           text
+*.cql           text
+*.df            text
+*.ejs           text
+*.html          text
+*.java          text
+*.js            text
+*.json          text
+*.less          text
+*.properties    text
+*.sass          text
+*.scss          text
+*.sh            text eol=lf
+*.sql           text
+*.txt           text
+*.ts            text
+*.xml           text
+*.yaml          text
+*.yml           text
+
+# Documents
+*.doc           diff=astextplain
+*.DOC           diff=astextplain
+*.docx          diff=astextplain
+*.DOCX          diff=astextplain
+*.dot           diff=astextplain
+*.DOT           diff=astextplain
+*.pdf           diff=astextplain
+*.PDF           diff=astextplain
+*.rtf           diff=astextplain
+*.RTF           diff=astextplain
+*.markdown      text
+*.md            text
+*.adoc          text
+*.textile       text
+*.mustache      text
+*.csv           text
+*.tab           text
+*.tsv           text
+*.txt           text
+AUTHORS         text
+CHANGELOG       text
+CHANGES         text
+CONTRIBUTING    text
+COPYING         text
+copyright       text
+*COPYRIGHT*     text
+INSTALL         text
+license         text
+LICENSE         text
+NEWS            text
+readme          text
+*README*        text
+TODO            text
+
+# Graphics
+*.png           binary
+*.jpg           binary
+*.jpeg          binary
+*.gif           binary
+*.tif           binary
+*.tiff          binary
+*.ico           binary
+# SVG treated as an asset (binary) by default. If you want to treat it as text,
+# comment-out the following line and uncomment the line after.
+*.svg           binary
+#*.svg          text
+*.eps           binary
+
+# These files are binary and should be left untouched
+# (binary is a macro for -text -diff)
+*.class         binary
+*.jar           binary
+*.war           binary
+
+## LINTERS
+.csslintrc      text
+.eslintrc       text
+.jscsrc         text
+.jshintrc       text
+.jshintignore   text
+.stylelintrc    text
+
+## CONFIGS
+*.bowerrc       text
+*.conf          text
+*.config        text
+.editorconfig   text
+.gitattributes  text
+.gitconfig      text
+.gitignore      text
+.htaccess       text
+*.npmignore     text
+
+## HEROKU
+Procfile        text
+.slugignore     text
+
+## AUDIO
+*.kar           binary
+*.m4a           binary
+*.mid           binary
+*.midi          binary
+*.mp3           binary
+*.ogg           binary
+*.ra            binary
+
+## VIDEO
+*.3gpp          binary
+*.3gp           binary
+*.as            binary
+*.asf           binary
+*.asx           binary
+*.fla           binary
+*.flv           binary
+*.m4v           binary
+*.mng           binary
+*.mov           binary
+*.mp4           binary
+*.mpeg          binary
+*.mpg           binary
+*.swc           binary
+*.swf           binary
+*.webm          binary
+
+## ARCHIVES
+*.7z            binary
+*.gz            binary
+*.rar           binary
+*.tar           binary
+*.zip           binary
+
+## FONTS
+*.ttf           binary
+*.eot           binary
+*.otf           binary
+*.woff          binary
+*.woff2         binary

jhipster/jhipster-uaa/gateway/.gitignore

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+######################
+# Project Specific
+######################
+/src/main/webapp/content/css/main.css
+/target/www/**
+/src/test/javascript/coverage/
+
+######################
+# Node
+######################
+/node/
+node_tmp/
+node_modules/
+npm-debug.log.*
+/.awcache/*
+/.cache-loader/*
+
+######################
+# SASS
+######################
+.sass-cache/
+
+######################
+# Eclipse
+######################
+*.pydevproject
+.project
+.metadata
+tmp/
+tmp/**/*
+*.tmp
+*.bak
+*.swp
+*~.nib
+local.properties
+.classpath
+.settings/
+.loadpath
+.factorypath
+/src/main/resources/rebel.xml
+
+# External tool builders
+.externalToolBuilders/**
+
+# Locally stored "Eclipse launch configurations"
+*.launch
+
+# CDT-specific
+.cproject
+
+# PDT-specific
+.buildpath
+
+######################
+# Intellij
+######################
+.idea/
+*.iml
+*.iws
+*.ipr
+*.ids
+*.orig
+classes/
+out/
+
+######################
+# Visual Studio Code
+######################
+.vscode/
+
+######################
+# Maven
+######################
+/log/
+/target/
+
+######################
+# Gradle
+######################
+.gradle/
+/build/
+
+######################
+# Package Files
+######################
+*.jar
+*.war
+*.ear
+*.db
+
+######################
+# Windows
+######################
+# Windows image file caches
+Thumbs.db
+
+# Folder config file
+Desktop.ini
+
+######################
+# Mac OSX
+######################
+.DS_Store
+.svn
+
+# Thumbnails
+._*
+
+# Files that might appear on external disk
+.Spotlight-V100
+.Trashes
+
+######################
+# Directories
+######################
+/bin/
+/deploy/
+
+######################
+# Logs
+######################
+*.log*
+
+######################
+# Others
+######################
+*.class
+*.*~
+*~
+.merge_file*
+
+######################
+# Gradle Wrapper
+######################
+!gradle/wrapper/gradle-wrapper.jar
+
+######################
+# Maven Wrapper
+######################
+!.mvn/wrapper/maven-wrapper.jar
+
+######################
+# ESLint
+######################
+.eslintcache

jhipster/jhipster-uaa/gateway/.huskyrc

@@ -0,0 +1,5 @@
+{
+  "hooks": {
+     "pre-commit": "lint-staged"
+  }
+}

jhipster/jhipster-uaa/gateway/.jhipster/Quote.json

@@ -0,0 +1,38 @@
+{
+    "name": "Quote",
+    "fields": [
+        {
+            "fieldName": "symbol",
+            "fieldType": "String",
+            "fieldValidateRules": [
+                "required",
+                "unique"
+            ]
+        },
+        {
+            "fieldName": "price",
+            "fieldType": "BigDecimal",
+            "fieldValidateRules": [
+                "required"
+            ]
+        },
+        {
+            "fieldName": "lastTrade",
+            "fieldType": "ZonedDateTime",
+            "fieldValidateRules": [
+                "required"
+            ]
+        }
+    ],
+    "relationships": [],
+    "changelogDate": "20181020145525",
+    "entityTableName": "quote",
+    "dto": "mapstruct",
+    "pagination": "pagination",
+    "service": "serviceImpl",
+    "jpaMetamodelFiltering": true,
+    "fluentMethods": true,
+    "clientRootFolder": "quotes",
+    "applications": "*",
+    "microserviceName": "quotes"
+}

jhipster/jhipster-uaa/gateway/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,110 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+*/
+
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL =
+            "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: : " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output direcrory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

jhipster/jhipster-uaa/gateway/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.5.4/apache-maven-3.5.4-bin.zip

jhipster/jhipster-uaa/gateway/.prettierignore

@@ -0,0 +1,2 @@
+node_modules
+target

jhipster/jhipster-uaa/gateway/.prettierrc

@@ -0,0 +1,12 @@
+# Prettier configuration
+
+printWidth: 140
+singleQuote: true
+tabWidth: 4
+useTabs: false
+
+# js and ts rules:
+arrowParens: avoid
+
+# jsx and tsx rules:
+jsxBracketSameLine: false

jhipster/jhipster-uaa/gateway/.yo-rc.json

@@ -0,0 +1,39 @@
+{
+  "generator-jhipster": {
+    "promptValues": {
+      "packageName": "com.baeldung.jhipster.gateway",
+      "nativeLanguage": "en"
+    },
+    "jhipsterVersion": "5.4.2",
+    "applicationType": "gateway",
+    "baseName": "gateway",
+    "packageName": "com.baeldung.jhipster.gateway",
+    "packageFolder": "com/baeldung/jhipster/gateway",
+    "serverPort": "8080",
+    "authenticationType": "uaa",
+    "uaaBaseName": "uaa",
+    "cacheProvider": "hazelcast",
+    "enableHibernateCache": true,
+    "websocket": false,
+    "databaseType": "sql",
+    "devDatabaseType": "h2Disk",
+    "prodDatabaseType": "mysql",
+    "searchEngine": false,
+    "messageBroker": false,
+    "serviceDiscoveryType": "eureka",
+    "buildTool": "maven",
+    "enableSwaggerCodegen": false,
+    "clientFramework": "angularX",
+    "useSass": true,
+    "clientPackageManager": "npm",
+    "testFrameworks": [],
+    "jhiPrefix": "jhi",
+    "enableTranslation": true,
+    "nativeLanguage": "en",
+    "languages": [
+      "en",
+      "fr",
+      "pt-br"
+    ]
+  }
+}

jhipster/jhipster-uaa/gateway/README.md

@@ -0,0 +1,186 @@
+# gateway
+This application was generated using JHipster 5.4.2, you can find documentation and help at [https://www.jhipster.tech/documentation-archive/v5.4.2](https://www.jhipster.tech/documentation-archive/v5.4.2).
+
+This is a "gateway" application intended to be part of a microservice architecture, please refer to the [Doing microservices with JHipster][] page of the documentation for more information.
+
+This application is configured for Service Discovery and Configuration with the JHipster-Registry. On launch, it will refuse to start if it is not able to connect to the JHipster-Registry at [http://localhost:8761](http://localhost:8761). For more information, read our documentation on [Service Discovery and Configuration with the JHipster-Registry][].
+
+## Development
+
+Before you can build this project, you must install and configure the following dependencies on your machine:
+
+1. [Node.js][]: We use Node to run a development web server and build the project.
+   Depending on your system, you can install Node either from source or as a pre-packaged bundle.
+
+After installing Node, you should be able to run the following command to install development tools.
+You will only need to run this command when dependencies change in [package.json](package.json).
+
+    npm install
+
+We use npm scripts and [Webpack][] as our build system.
+
+Run the following commands in two separate terminals to create a blissful development experience where your browser
+auto-refreshes when files change on your hard drive.
+
+    ./mvnw
+    npm start
+
+Npm is also used to manage CSS and JavaScript dependencies used in this application. You can upgrade dependencies by
+specifying a newer version in [package.json](package.json). You can also run `npm update` and `npm install` to manage dependencies.
+Add the `help` flag on any command to see how you can use it. For example, `npm help update`.
+
+The `npm run` command will list all of the scripts available to run for this project.
+
+### Service workers
+
+Service workers are commented by default, to enable them please uncomment the following code.
+
+* The service worker registering script in index.html
+
+```html
+<script>
+    if ('serviceWorker' in navigator) {
+        navigator.serviceWorker
+        .register('./service-worker.js')
+        .then(function() { console.log('Service Worker Registered'); });
+    }
+</script>
+```
+
+Note: workbox creates the respective service worker and dynamically generate the `service-worker.js`
+
+### Managing dependencies
+
+For example, to add [Leaflet][] library as a runtime dependency of your application, you would run following command:
+
+    npm install --save --save-exact leaflet
+
+To benefit from TypeScript type definitions from [DefinitelyTyped][] repository in development, you would run following command:
+
+    npm install --save-dev --save-exact @types/leaflet
+
+Then you would import the JS and CSS files specified in library's installation instructions so that [Webpack][] knows about them:
+Edit [src/main/webapp/app/vendor.ts](src/main/webapp/app/vendor.ts) file:
+~~~
+import 'leaflet/dist/leaflet.js';
+~~~
+
+Edit [src/main/webapp/content/css/vendor.css](src/main/webapp/content/css/vendor.css) file:
+~~~
+@import '~leaflet/dist/leaflet.css';
+~~~
+Note: there are still few other things remaining to do for Leaflet that we won't detail here.
+
+For further instructions on how to develop with JHipster, have a look at [Using JHipster in development][].
+
+### Using angular-cli
+
+You can also use [Angular CLI][] to generate some custom client code.
+
+For example, the following command:
+
+    ng generate component my-component
+
+will generate few files:
+
+    create src/main/webapp/app/my-component/my-component.component.html
+    create src/main/webapp/app/my-component/my-component.component.ts
+    update src/main/webapp/app/app.module.ts
+
+
+## Building for production
+
+To optimize the gateway application for production, run:
+
+    ./mvnw -Pprod clean package
+
+This will concatenate and minify the client CSS and JavaScript files. It will also modify `index.html` so it references these new files.
+To ensure everything worked, run:
+
+    java -jar target/*.war
+
+Then navigate to [http://localhost:8080](http://localhost:8080) in your browser.
+
+Refer to [Using JHipster in production][] for more details.
+
+## Testing
+
+To launch your application's tests, run:
+
+    ./mvnw clean test
+
+### Client tests
+
+Unit tests are run by [Jest][] and written with [Jasmine][]. They're located in [src/test/javascript/](src/test/javascript/) and can be run with:
+
+    npm test
+
+
+
+For more information, refer to the [Running tests page][].
+
+### Code quality
+
+Sonar is used to analyse code quality. You can start a local Sonar server (accessible on http://localhost:9001) with:
+
+```
+docker-compose -f src/main/docker/sonar.yml up -d
+```
+
+Then, run a Sonar analysis:
+
+```
+./mvnw -Pprod clean test sonar:sonar
+```
+
+For more information, refer to the [Code quality page][].
+
+## Using Docker to simplify development (optional)
+
+You can use Docker to improve your JHipster development experience. A number of docker-compose configuration are available in the [src/main/docker](src/main/docker) folder to launch required third party services.
+
+For example, to start a mysql database in a docker container, run:
+
+    docker-compose -f src/main/docker/mysql.yml up -d
+
+To stop it and remove the container, run:
+
+    docker-compose -f src/main/docker/mysql.yml down
+
+You can also fully dockerize your application and all the services that it depends on.
+To achieve this, first build a docker image of your app by running:
+
+    ./mvnw package -Pprod jib:dockerBuild
+
+Then run:
+
+    docker-compose -f src/main/docker/app.yml up -d
+
+For more information refer to [Using Docker and Docker-Compose][], this page also contains information on the docker-compose sub-generator (`jhipster docker-compose`), which is able to generate docker configurations for one or several JHipster applications.
+
+## Continuous Integration (optional)
+
+To configure CI for your project, run the ci-cd sub-generator (`jhipster ci-cd`), this will let you generate configuration files for a number of Continuous Integration systems. Consult the [Setting up Continuous Integration][] page for more information.
+
+[JHipster Homepage and latest documentation]: https://www.jhipster.tech
+[JHipster 5.4.2 archive]: https://www.jhipster.tech/documentation-archive/v5.4.2
+[Doing microservices with JHipster]: https://www.jhipster.tech/documentation-archive/v5.4.2/microservices-architecture/
+[Using JHipster in development]: https://www.jhipster.tech/documentation-archive/v5.4.2/development/
+[Service Discovery and Configuration with the JHipster-Registry]: https://www.jhipster.tech/documentation-archive/v5.4.2/microservices-architecture/#jhipster-registry
+[Using Docker and Docker-Compose]: https://www.jhipster.tech/documentation-archive/v5.4.2/docker-compose
+[Using JHipster in production]: https://www.jhipster.tech/documentation-archive/v5.4.2/production/
+[Running tests page]: https://www.jhipster.tech/documentation-archive/v5.4.2/running-tests/
+[Code quality page]: https://www.jhipster.tech/documentation-archive/v5.4.2/code-quality/
+[Setting up Continuous Integration]: https://www.jhipster.tech/documentation-archive/v5.4.2/setting-up-ci/
+
+
+[Node.js]: https://nodejs.org/
+[Yarn]: https://yarnpkg.org/
+[Webpack]: https://webpack.github.io/
+[Angular CLI]: https://cli.angular.io/
+[BrowserSync]: http://www.browsersync.io/
+[Jest]: https://facebook.github.io/jest/
+[Jasmine]: http://jasmine.github.io/2.0/introduction.html
+[Protractor]: https://angular.github.io/protractor/
+[Leaflet]: http://leafletjs.com/
+[DefinitelyTyped]: http://definitelytyped.org/

jhipster/jhipster-uaa/gateway/angular.json

@@ -0,0 +1,39 @@
+{
+  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
+  "version": 1,
+  "newProjectRoot": "projects",
+  "projects": {
+    "gateway": {
+      "root": "",
+      "sourceRoot": "src/main/webapp",
+      "projectType": "application",
+      "architect": {}
+    }
+  },
+  "defaultProject": "gateway",
+  "cli": {
+    "packageManager": "yarn"
+  },
+  "schematics": {
+    "@schematics/angular:component": {
+      "inlineStyle": true,
+      "inlineTemplate": false,
+      "spec": false,
+      "prefix": "jhi",
+      "styleExt": "scss"
+    },
+    "@schematics/angular:directive": {
+      "spec": false,
+      "prefix": "jhi"
+    },
+    "@schematics/angular:guard": {
+      "spec": false
+    },
+    "@schematics/angular:pipe": {
+      "spec": false
+    },
+    "@schematics/angular:service": {
+      "spec": false
+    }
+  }
+}

jhipster/jhipster-uaa/gateway/mvnw

@@ -0,0 +1,286 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven2 Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+  # TODO classpath?
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar"
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        wget "$jarUrl" -O "$wrapperJarPath"
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        curl -o "$wrapperJarPath" "$jarUrl"
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

jhipster/jhipster-uaa/gateway/mvnw.cmd

@@ -0,0 +1,161 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    http://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven2 Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a key stroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing my setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar"
+FOR /F "tokens=1,2 delims==" %%A IN (%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties) DO (
+	IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B 
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    echo Found %WRAPPER_JAR%
+) else (
+    echo Couldn't find %WRAPPER_JAR%, downloading it ...
+	echo Downloading from: %DOWNLOAD_URL%
+    powershell -Command "(New-Object Net.WebClient).DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"
+    echo Finished downloading %WRAPPER_JAR%
+)
+@REM End of extension
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

jhipster/jhipster-uaa/gateway/package.json

@@ -0,0 +1,131 @@
+{
+  "name": "gateway",
+  "version": "0.0.0",
+  "description": "Description for gateway",
+  "private": true,
+  "license": "UNLICENSED",
+  "cacheDirectories": [
+    "node_modules"
+  ],
+  "dependencies": {
+    "@angular/common": "6.1.0",
+    "@angular/compiler": "6.1.0",
+    "@angular/core": "6.1.0",
+    "@angular/forms": "6.1.0",
+    "@angular/platform-browser": "6.1.0",
+    "@angular/platform-browser-dynamic": "6.1.0",
+    "@angular/router": "6.1.0",
+    "@fortawesome/angular-fontawesome": "0.2.0",
+    "@fortawesome/fontawesome-svg-core": "1.2.4",
+    "@fortawesome/free-solid-svg-icons": "5.3.1",
+    "@ng-bootstrap/ng-bootstrap": "3.0.0",
+    "bootstrap": "4.1.3",
+    "core-js": "2.5.7",
+    "moment": "2.22.2",
+    "ng-jhipster": "0.5.4",
+    "ngx-cookie": "2.0.1",
+    "ngx-infinite-scroll": "0.5.1",
+    "ngx-webstorage": "2.0.1",
+    "reflect-metadata": "0.1.12",
+    "rxjs": "6.1.0",
+    "rxjs-compat": "6.1.0",
+    "swagger-ui": "2.2.10",
+    "tslib": "1.9.3",
+    "zone.js": "0.8.26"
+  },
+  "devDependencies": {
+    "@angular/cli": "6.1.2",
+    "@angular/compiler-cli": "6.1.0",
+    "@ngtools/webpack": "6.0.0",
+    "@types/jest": "22.2.3",
+    "@types/node": "9.4.7",
+    "angular-router-loader": "0.8.5",
+    "angular2-template-loader": "0.6.2",
+    "browser-sync": "2.24.6",
+    "browser-sync-webpack-plugin": "2.2.2",
+    "cache-loader": "1.2.2",
+    "codelyzer": "4.2.1",
+    "copy-webpack-plugin": "4.5.1",
+    "css-loader": "0.28.10",
+    "exports-loader": "0.7.0",
+    "file-loader": "1.1.11",
+    "fork-ts-checker-webpack-plugin": "0.4.1",
+    "friendly-errors-webpack-plugin": "1.7.0",
+    "generator-jhipster": "5.4.2",
+    "html-loader": "0.5.5",
+    "html-webpack-plugin": "3.2.0",
+    "husky": "1.1.0",
+    "jest": "22.4.3",
+    "jest-junit": "5.1.0",
+    "jest-preset-angular": "5.2.2",
+    "jest-sonar-reporter": "2.0.0",
+    "lint-staged": "7.3.0",
+    "merge-jsons-webpack-plugin": "1.0.14",
+    "mini-css-extract-plugin": "0.4.2",
+    "moment-locales-webpack-plugin": "1.0.5",
+    "optimize-css-assets-webpack-plugin": "5.0.1",
+    "prettier": "1.11.1",
+    "proxy-middleware": "0.15.0",
+    "raw-loader": "0.5.1",
+    "rimraf": "2.6.1",
+    "simple-progress-webpack-plugin": "1.1.2",
+    "style-loader": "0.20.3",
+    "tapable": "1.0.0",
+    "terser-webpack-plugin": "1.0.0",
+    "thread-loader": "1.1.5",
+    "to-string-loader": "1.1.5",
+    "ts-loader": "4.0.1",
+    "tslint": "5.9.1",
+    "tslint-config-prettier": "1.9.0",
+    "tslint-loader": "3.6.0",
+    "typescript": "2.7.2",
+    "sass": "1.13.0",
+    "sass-loader": "7.1.0",
+    "postcss-loader": "2.1.1",
+    "xml2js": "0.4.19",
+    "webpack": "4.8.0",
+    "webpack-cli": "2.1.3",
+    "webpack-dev-server": "3.1.5",
+    "webpack-merge": "4.1.2",
+    "webpack-notifier": "1.6.0",
+    "webpack-visualizer-plugin": "0.1.11",
+    "workbox-webpack-plugin": "3.2.0",
+    "write-file-webpack-plugin": "4.2.0"
+  },
+  "engines": {
+    "node": ">=8.9.0"
+  },
+  "lint-staged": {
+    "src/**/*.{ts,css,scss}": [
+      "prettier --write",
+      "git add"
+    ]
+  },
+  "scripts": {
+    "prettier:format": "prettier --write \"src/**/*.{ts,css,scss}\"",
+    "lint": "tslint --project tsconfig.json -e 'node_modules/**'",
+    "lint:fix": "npm run lint -- --fix",
+    "ngc": "ngc -p tsconfig-aot.json",
+    "cleanup": "rimraf target/{aot,www}",
+    "clean-www": "rimraf target//www/app/{src,target/}",
+    "start": "npm run webpack:dev",
+    "start-tls": "npm run webpack:dev -- --env.tls",
+    "serve": "npm run start",
+    "build": "npm run webpack:prod",
+    "test": "npm run lint && jest --coverage --logHeapUsage -w=2 --config src/test/javascript/jest.conf.js",
+    "test:watch": "npm test -- --watch --clearCache",
+    "webpack:dev": "npm run webpack-dev-server -- --config webpack/webpack.dev.js --inline --hot --port=9060 --watch-content-base --env.stats=minimal",
+    "webpack:dev-verbose": "npm run webpack-dev-server -- --config webpack/webpack.dev.js --inline --hot --port=9060 --watch-content-base --profile --progress --env.stats=normal",
+    "webpack:build:main": "npm run webpack -- --config webpack/webpack.dev.js --env.stats=normal",
+    "webpack:build": "npm run cleanup && npm run webpack:build:main",
+    "webpack:prod:main": "npm run webpack -- --config webpack/webpack.prod.js --profile",
+    "webpack:prod": "npm run cleanup && npm run webpack:prod:main && npm run clean-www",
+    "webpack:test": "npm run test",
+    "webpack-dev-server": "node --max_old_space_size=4096 node_modules/webpack-dev-server/bin/webpack-dev-server.js",
+    "webpack": "node --max_old_space_size=4096 node_modules/webpack/bin/webpack.js"
+  },
+  "jestSonar": {
+    "reportPath": "target/test-results/jest",
+    "reportFile": "TESTS-results-sonar.xml"
+  }
+}

jhipster/jhipster-uaa/gateway/postcss.config.js

@@ -0,0 +1,3 @@
+module.exports = {
+    plugins: []
+}

jhipster/jhipster-uaa/gateway/proxy.conf.json

@@ -0,0 +1,7 @@
+{
+    "*": {
+        "target": "http://localhost:8080",
+        "secure": false,
+        "loglevel": "debug"
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/docker/.dockerignore

@@ -0,0 +1,14 @@
+# https://docs.docker.com/engine/reference/builder/#dockerignore-file
+classes/
+generated-sources/
+generated-test-sources/
+h2db/
+maven-archiver/
+maven-status/
+reports/
+surefire-reports/
+test-classes/
+test-results/
+www/
+!*.jar
+!*.war

jhipster/jhipster-uaa/gateway/src/main/docker/Dockerfile

@@ -0,0 +1,20 @@
+FROM openjdk:8-jre-alpine
+
+ENV SPRING_OUTPUT_ANSI_ENABLED=ALWAYS \
+    JHIPSTER_SLEEP=0 \
+    JAVA_OPTS=""
+
+# Add a jhipster user to run our application so that it doesn't need to run as root
+RUN adduser -D -s /bin/sh jhipster
+WORKDIR /home/jhipster
+
+ADD entrypoint.sh entrypoint.sh
+RUN chmod 755 entrypoint.sh && chown jhipster:jhipster entrypoint.sh
+USER jhipster
+
+ENTRYPOINT ["./entrypoint.sh"]
+
+EXPOSE 8080 5701/udp
+
+ADD *.war app.war
+

jhipster/jhipster-uaa/gateway/src/main/docker/app.yml

@@ -0,0 +1,24 @@
+version: '2'
+services:
+    gateway-app:
+        image: gateway
+        environment:
+            # - _JAVA_OPTIONS=-Xmx512m -Xms256m
+            - SPRING_PROFILES_ACTIVE=prod,swagger
+            - EUREKA_CLIENT_SERVICE_URL_DEFAULTZONE=http://admin:$${jhipster.registry.password}@jhipster-registry:8761/eureka
+            - SPRING_CLOUD_CONFIG_URI=http://admin:$${jhipster.registry.password}@jhipster-registry:8761/config
+            - SPRING_DATASOURCE_URL=jdbc:mysql://gateway-mysql:3306/gateway?useUnicode=true&characterEncoding=utf8&useSSL=false
+            - JHIPSTER_SLEEP=30 # gives time for the JHipster Registry to boot before the application
+        ports:
+            - 8080:8080
+    gateway-mysql:
+        extends:
+            file: mysql.yml
+            service: gateway-mysql
+    jhipster-registry:
+        extends:
+            file: jhipster-registry.yml
+            service: jhipster-registry
+        environment:
+            - SPRING_CLOUD_CONFIG_SERVER_COMPOSITE_0_TYPE=native
+            - SPRING_CLOUD_CONFIG_SERVER_COMPOSITE_0_SEARCH_LOCATIONS=file:./central-config/docker-config/

jhipster/jhipster-uaa/gateway/src/main/docker/central-server-config/README.md

@@ -0,0 +1,7 @@
+# Central configuration sources details
+
+The JHipster-Registry will use the following directories as its configuration source :
+- localhost-config : when running the registry in docker with the jhipster-registry.yml docker-compose file
+- docker-config : when running the registry and the app both in docker with the app.yml docker-compose file
+
+For more info, refer to https://www.jhipster.tech/microservices-architecture/#registry_app_configuration

jhipster/jhipster-uaa/gateway/src/main/docker/central-server-config/docker-config/application.yml

@@ -0,0 +1,15 @@
+# Common configuration shared between all applications
+configserver:
+    name: Docker JHipster Registry
+    status: Connected to the JHipster Registry running in Docker
+
+jhipster:
+    security:
+        authentication:
+            jwt:
+                secret: my-secret-key-which-should-be-changed-in-production-and-be-base64-encoded
+
+eureka:
+    client:
+        service-url:
+            defaultZone: http://admin:${jhipster.registry.password}@jhipster-registry:8761/eureka/

jhipster/jhipster-uaa/gateway/src/main/docker/central-server-config/localhost-config/application.yml

@@ -0,0 +1,15 @@
+# Common configuration shared between all applications
+configserver:
+    name: Docker JHipster Registry
+    status: Connected to the JHipster Registry running in Docker
+
+jhipster:
+    security:
+        authentication:
+            jwt:
+                secret: my-secret-key-which-should-be-changed-in-production-and-be-base64-encoded
+
+eureka:
+    client:
+        service-url:
+            defaultZone: http://admin:${jhipster.registry.password}@localhost:8761/eureka/

jhipster/jhipster-uaa/gateway/src/main/docker/entrypoint.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+echo "The application will start in ${JHIPSTER_SLEEP}s..." && sleep ${JHIPSTER_SLEEP}
+exec java ${JAVA_OPTS} -Djava.security.egd=file:/dev/./urandom -jar "${HOME}/app.war" "$@"

jhipster/jhipster-uaa/gateway/src/main/docker/hazelcast-management-center.yml

@@ -0,0 +1,6 @@
+version: '2'
+services:
+    gateway-hazelcast-management-center:
+        image: hazelcast/management-center:3.9.3
+        ports:
+            - 8180:8080

jhipster/jhipster-uaa/gateway/src/main/docker/jhipster-registry.yml

@@ -0,0 +1,22 @@
+version: '2'
+services:
+    jhipster-registry:
+        image: jhipster/jhipster-registry:v4.0.4
+        volumes:
+            - ./central-server-config:/central-config
+        # When run with the "dev" Spring profile, the JHipster Registry will
+        # read the config from the local filesystem (central-server-config directory)
+        # When run with the "prod" Spring profile, it will read the configuration from a Git repository
+        # See https://www.jhipster.tech/microservices-architecture/#registry_app_configuration
+        environment:
+            # - _JAVA_OPTIONS=-Xmx512m -Xms256m
+            - SPRING_PROFILES_ACTIVE=dev,swagger,uaa
+            - SPRING_SECURITY_USER_PASSWORD=admin
+            - JHIPSTER_REGISTRY_PASSWORD=admin
+            - SPRING_CLOUD_CONFIG_SERVER_COMPOSITE_0_TYPE=native
+            - SPRING_CLOUD_CONFIG_SERVER_COMPOSITE_0_SEARCH_LOCATIONS=file:./central-config/localhost-config/
+            # - SPRING_CLOUD_CONFIG_SERVER_COMPOSITE_0_TYPE=git
+            # - SPRING_CLOUD_CONFIG_SERVER_COMPOSITE_0_URI=https://github.com/jhipster/jhipster-registry/
+            # - SPRING_CLOUD_CONFIG_SERVER_COMPOSITE_0_SEARCH_PATHS=central-config
+        ports:
+            - 8761:8761

jhipster/jhipster-uaa/gateway/src/main/docker/mysql.yml

@@ -0,0 +1,13 @@
+version: '2'
+services:
+    gateway-mysql:
+        image: mysql:5.7.20
+        # volumes:
+        #     - ~/volumes/jhipster/gateway/mysql/:/var/lib/mysql/
+        environment:
+            - MYSQL_USER=root
+            - MYSQL_ALLOW_EMPTY_PASSWORD=yes
+            - MYSQL_DATABASE=gateway
+        ports:
+            - 3306:3306
+        command: mysqld --lower_case_table_names=1 --skip-ssl --character_set_server=utf8mb4 --explicit_defaults_for_timestamp

jhipster/jhipster-uaa/gateway/src/main/docker/sonar.yml

@@ -0,0 +1,7 @@
+version: '2'
+services:
+    gateway-sonar:
+        image: sonarqube:7.1-alpine
+        ports:
+            - 9001:9000
+            - 9092:9092

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/ApplicationWebXml.java

@@ -0,0 +1,21 @@
+package com.baeldung.jhipster.gateway;
+
+import com.baeldung.jhipster.gateway.config.DefaultProfileUtil;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+
+/**
+ * This is a helper Java class that provides an alternative to creating a web.xml.
+ * This will be invoked only when the application is deployed to a Servlet container like Tomcat, JBoss etc.
+ */
+public class ApplicationWebXml extends SpringBootServletInitializer {
+
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+        /**
+         * set a default to use when no profile is configured.
+         */
+        DefaultProfileUtil.addDefaultProfile(application.application());
+        return application.sources(GatewayApp.class);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/GatewayApp.java

@@ -0,0 +1,109 @@
+package com.baeldung.jhipster.gateway;
+
+import com.baeldung.jhipster.gateway.config.ApplicationProperties;
+import com.baeldung.jhipster.gateway.config.DefaultProfileUtil;
+
+import io.github.jhipster.config.JHipsterConstants;
+
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.liquibase.LiquibaseProperties;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
+import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
+import org.springframework.core.env.Environment;
+
+import javax.annotation.PostConstruct;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Arrays;
+import java.util.Collection;
+
+@SpringBootApplication
+@EnableConfigurationProperties({LiquibaseProperties.class, ApplicationProperties.class})
+@EnableDiscoveryClient
+@EnableZuulProxy
+public class GatewayApp {
+
+    private static final Logger log = LoggerFactory.getLogger(GatewayApp.class);
+
+    private final Environment env;
+
+    public GatewayApp(Environment env) {
+        this.env = env;
+    }
+
+    /**
+     * Initializes gateway.
+     * <p>
+     * Spring profiles can be configured with a program argument --spring.profiles.active=your-active-profile
+     * <p>
+     * You can find more information on how profiles work with JHipster on <a href="https://www.jhipster.tech/profiles/">https://www.jhipster.tech/profiles/</a>.
+     */
+    @PostConstruct
+    public void initApplication() {
+        Collection<String> activeProfiles = Arrays.asList(env.getActiveProfiles());
+        if (activeProfiles.contains(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT) && activeProfiles.contains(JHipsterConstants.SPRING_PROFILE_PRODUCTION)) {
+            log.error("You have misconfigured your application! It should not run " +
+                "with both the 'dev' and 'prod' profiles at the same time.");
+        }
+        if (activeProfiles.contains(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT) && activeProfiles.contains(JHipsterConstants.SPRING_PROFILE_CLOUD)) {
+            log.error("You have misconfigured your application! It should not " +
+                "run with both the 'dev' and 'cloud' profiles at the same time.");
+        }
+    }
+
+    /**
+     * Main method, used to run the application.
+     *
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) {
+        SpringApplication app = new SpringApplication(GatewayApp.class);
+        DefaultProfileUtil.addDefaultProfile(app);
+        Environment env = app.run(args).getEnvironment();
+        logApplicationStartup(env);
+    }
+
+    private static void logApplicationStartup(Environment env) {
+        String protocol = "http";
+        if (env.getProperty("server.ssl.key-store") != null) {
+            protocol = "https";
+        }
+        String serverPort = env.getProperty("server.port");
+        String contextPath = env.getProperty("server.servlet.context-path");
+        if (StringUtils.isBlank(contextPath)) {
+            contextPath = "/";
+        }
+        String hostAddress = "localhost";
+        try {
+            hostAddress = InetAddress.getLocalHost().getHostAddress();
+        } catch (UnknownHostException e) {
+            log.warn("The host name could not be determined, using `localhost` as fallback");
+        }
+        log.info("\n----------------------------------------------------------\n\t" +
+                "Application '{}' is running! Access URLs:\n\t" +
+                "Local: \t\t{}://localhost:{}{}\n\t" +
+                "External: \t{}://{}:{}{}\n\t" +
+                "Profile(s): \t{}\n----------------------------------------------------------",
+            env.getProperty("spring.application.name"),
+            protocol,
+            serverPort,
+            contextPath,
+            protocol,
+            hostAddress,
+            serverPort,
+            contextPath,
+            env.getActiveProfiles());
+
+        String configServerStatus = env.getProperty("configserver.status");
+        if (configServerStatus == null) {
+            configServerStatus = "Not found or not setup for this application";
+        }
+        log.info("\n----------------------------------------------------------\n\t" +
+                "Config Server: \t{}\n----------------------------------------------------------", configServerStatus);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/aop/logging/LoggingAspect.java

@@ -0,0 +1,98 @@
+package com.baeldung.jhipster.gateway.aop.logging;
+
+import io.github.jhipster.config.JHipsterConstants;
+
+import org.aspectj.lang.JoinPoint;
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.AfterThrowing;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.aspectj.lang.annotation.Pointcut;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.core.env.Environment;
+
+import java.util.Arrays;
+
+/**
+ * Aspect for logging execution of service and repository Spring components.
+ *
+ * By default, it only runs with the "dev" profile.
+ */
+@Aspect
+public class LoggingAspect {
+
+    private final Logger log = LoggerFactory.getLogger(this.getClass());
+
+    private final Environment env;
+
+    public LoggingAspect(Environment env) {
+        this.env = env;
+    }
+
+    /**
+     * Pointcut that matches all repositories, services and Web REST endpoints.
+     */
+    @Pointcut("within(@org.springframework.stereotype.Repository *)" +
+        " || within(@org.springframework.stereotype.Service *)" +
+        " || within(@org.springframework.web.bind.annotation.RestController *)")
+    public void springBeanPointcut() {
+        // Method is empty as this is just a Pointcut, the implementations are in the advices.
+    }
+
+    /**
+     * Pointcut that matches all Spring beans in the application's main packages.
+     */
+    @Pointcut("within(com.baeldung.jhipster.gateway.repository..*)"+
+        " || within(com.baeldung.jhipster.gateway.service..*)"+
+        " || within(com.baeldung.jhipster.gateway.web.rest..*)")
+    public void applicationPackagePointcut() {
+        // Method is empty as this is just a Pointcut, the implementations are in the advices.
+    }
+
+    /**
+     * Advice that logs methods throwing exceptions.
+     *
+     * @param joinPoint join point for advice
+     * @param e exception
+     */
+    @AfterThrowing(pointcut = "applicationPackagePointcut() && springBeanPointcut()", throwing = "e")
+    public void logAfterThrowing(JoinPoint joinPoint, Throwable e) {
+        if (env.acceptsProfiles(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT)) {
+            log.error("Exception in {}.{}() with cause = \'{}\' and exception = \'{}\'", joinPoint.getSignature().getDeclaringTypeName(),
+                joinPoint.getSignature().getName(), e.getCause() != null? e.getCause() : "NULL", e.getMessage(), e);
+
+        } else {
+            log.error("Exception in {}.{}() with cause = {}", joinPoint.getSignature().getDeclaringTypeName(),
+                joinPoint.getSignature().getName(), e.getCause() != null? e.getCause() : "NULL");
+        }
+    }
+
+    /**
+     * Advice that logs when a method is entered and exited.
+     *
+     * @param joinPoint join point for advice
+     * @return result
+     * @throws Throwable throws IllegalArgumentException
+     */
+    @Around("applicationPackagePointcut() && springBeanPointcut()")
+    public Object logAround(ProceedingJoinPoint joinPoint) throws Throwable {
+        if (log.isDebugEnabled()) {
+            log.debug("Enter: {}.{}() with argument[s] = {}", joinPoint.getSignature().getDeclaringTypeName(),
+                joinPoint.getSignature().getName(), Arrays.toString(joinPoint.getArgs()));
+        }
+        try {
+            Object result = joinPoint.proceed();
+            if (log.isDebugEnabled()) {
+                log.debug("Exit: {}.{}() with result = {}", joinPoint.getSignature().getDeclaringTypeName(),
+                    joinPoint.getSignature().getName(), result);
+            }
+            return result;
+        } catch (IllegalArgumentException e) {
+            log.error("Illegal argument: {} in {}.{}()", Arrays.toString(joinPoint.getArgs()),
+                joinPoint.getSignature().getDeclaringTypeName(), joinPoint.getSignature().getName());
+
+            throw e;
+        }
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/ApplicationProperties.java

@@ -0,0 +1,14 @@
+package com.baeldung.jhipster.gateway.config;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * Properties specific to Gateway.
+ * <p>
+ * Properties are configured in the application.yml file.
+ * See {@link io.github.jhipster.config.JHipsterProperties} for a good example.
+ */
+@ConfigurationProperties(prefix = "application", ignoreUnknownFields = false)
+public class ApplicationProperties {
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/AsyncConfiguration.java

@@ -0,0 +1,59 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.async.ExceptionHandlingAsyncTaskExecutor;
+import io.github.jhipster.config.JHipsterProperties;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
+import org.springframework.aop.interceptor.SimpleAsyncUncaughtExceptionHandler;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.*;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+import org.springframework.scheduling.annotation.SchedulingConfigurer;
+import org.springframework.scheduling.config.ScheduledTaskRegistrar;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+
+@Configuration
+@EnableAsync
+@EnableScheduling
+public class AsyncConfiguration implements AsyncConfigurer, SchedulingConfigurer {
+
+    private final Logger log = LoggerFactory.getLogger(AsyncConfiguration.class);
+
+    private final JHipsterProperties jHipsterProperties;
+
+    public AsyncConfiguration(JHipsterProperties jHipsterProperties) {
+        this.jHipsterProperties = jHipsterProperties;
+    }
+
+    @Override
+    @Bean(name = "taskExecutor")
+    public Executor getAsyncExecutor() {
+        log.debug("Creating Async Task Executor");
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(jHipsterProperties.getAsync().getCorePoolSize());
+        executor.setMaxPoolSize(jHipsterProperties.getAsync().getMaxPoolSize());
+        executor.setQueueCapacity(jHipsterProperties.getAsync().getQueueCapacity());
+        executor.setThreadNamePrefix("gateway-Executor-");
+        return new ExceptionHandlingAsyncTaskExecutor(executor);
+    }
+
+    @Override
+    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
+        return new SimpleAsyncUncaughtExceptionHandler();
+    }
+    
+    @Override
+    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
+        taskRegistrar.setScheduler(scheduledTaskExecutor());
+    }
+
+    @Bean
+    public Executor scheduledTaskExecutor() {
+        return Executors.newScheduledThreadPool(jHipsterProperties.getAsync().getCorePoolSize());
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/CacheConfiguration.java

@@ -0,0 +1,155 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.config.JHipsterConstants;
+import io.github.jhipster.config.JHipsterProperties;
+
+import com.hazelcast.config.*;
+import com.hazelcast.core.HazelcastInstance;
+import com.hazelcast.core.Hazelcast;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.client.serviceregistry.Registration;
+import org.springframework.context.annotation.*;
+import org.springframework.core.env.Environment;
+
+import javax.annotation.PreDestroy;
+
+@Configuration
+@EnableCaching
+public class CacheConfiguration {
+
+    private final Logger log = LoggerFactory.getLogger(CacheConfiguration.class);
+
+    private final Environment env;
+
+    private final ServerProperties serverProperties;
+
+    private final DiscoveryClient discoveryClient;
+
+    private Registration registration;
+
+    public CacheConfiguration(Environment env, ServerProperties serverProperties, DiscoveryClient discoveryClient) {
+        this.env = env;
+        this.serverProperties = serverProperties;
+        this.discoveryClient = discoveryClient;
+    }
+
+    @Autowired(required = false)
+    public void setRegistration(Registration registration) {
+        this.registration = registration;
+    }
+
+    @PreDestroy
+    public void destroy() {
+        log.info("Closing Cache Manager");
+        Hazelcast.shutdownAll();
+    }
+
+    @Bean
+    public CacheManager cacheManager(HazelcastInstance hazelcastInstance) {
+        log.debug("Starting HazelcastCacheManager");
+        CacheManager cacheManager = new com.hazelcast.spring.cache.HazelcastCacheManager(hazelcastInstance);
+        return cacheManager;
+    }
+
+    @Bean
+    public HazelcastInstance hazelcastInstance(JHipsterProperties jHipsterProperties) {
+        log.debug("Configuring Hazelcast");
+        HazelcastInstance hazelCastInstance = Hazelcast.getHazelcastInstanceByName("gateway");
+        if (hazelCastInstance != null) {
+            log.debug("Hazelcast already initialized");
+            return hazelCastInstance;
+        }
+        Config config = new Config();
+        config.setInstanceName("gateway");
+        config.getNetworkConfig().getJoin().getMulticastConfig().setEnabled(false);
+        if (this.registration == null) {
+            log.warn("No discovery service is set up, Hazelcast cannot create a cluster.");
+        } else {
+            // The serviceId is by default the application's name,
+            // see the "spring.application.name" standard Spring property
+            String serviceId = registration.getServiceId();
+            log.debug("Configuring Hazelcast clustering for instanceId: {}", serviceId);
+            // In development, everything goes through 127.0.0.1, with a different port
+            if (env.acceptsProfiles(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT)) {
+                log.debug("Application is running with the \"dev\" profile, Hazelcast " +
+                          "cluster will only work with localhost instances");
+
+                System.setProperty("hazelcast.local.localAddress", "127.0.0.1");
+                config.getNetworkConfig().setPort(serverProperties.getPort() + 5701);
+                config.getNetworkConfig().getJoin().getTcpIpConfig().setEnabled(true);
+                for (ServiceInstance instance : discoveryClient.getInstances(serviceId)) {
+                    String clusterMember = "127.0.0.1:" + (instance.getPort() + 5701);
+                    log.debug("Adding Hazelcast (dev) cluster member " + clusterMember);
+                    config.getNetworkConfig().getJoin().getTcpIpConfig().addMember(clusterMember);
+                }
+            } else { // Production configuration, one host per instance all using port 5701
+                config.getNetworkConfig().setPort(5701);
+                config.getNetworkConfig().getJoin().getTcpIpConfig().setEnabled(true);
+                for (ServiceInstance instance : discoveryClient.getInstances(serviceId)) {
+                    String clusterMember = instance.getHost() + ":5701";
+                    log.debug("Adding Hazelcast (prod) cluster member " + clusterMember);
+                    config.getNetworkConfig().getJoin().getTcpIpConfig().addMember(clusterMember);
+                }
+            }
+        }
+        config.getMapConfigs().put("default", initializeDefaultMapConfig(jHipsterProperties));
+
+        // Full reference is available at: http://docs.hazelcast.org/docs/management-center/3.9/manual/html/Deploying_and_Starting.html
+        config.setManagementCenterConfig(initializeDefaultManagementCenterConfig(jHipsterProperties));
+        config.getMapConfigs().put("com.baeldung.jhipster.gateway.domain.*", initializeDomainMapConfig(jHipsterProperties));
+        return Hazelcast.newHazelcastInstance(config);
+    }
+
+    private ManagementCenterConfig initializeDefaultManagementCenterConfig(JHipsterProperties jHipsterProperties) {
+        ManagementCenterConfig managementCenterConfig = new ManagementCenterConfig();
+        managementCenterConfig.setEnabled(jHipsterProperties.getCache().getHazelcast().getManagementCenter().isEnabled());
+        managementCenterConfig.setUrl(jHipsterProperties.getCache().getHazelcast().getManagementCenter().getUrl());
+        managementCenterConfig.setUpdateInterval(jHipsterProperties.getCache().getHazelcast().getManagementCenter().getUpdateInterval());
+        return managementCenterConfig;
+    }
+
+    private MapConfig initializeDefaultMapConfig(JHipsterProperties jHipsterProperties) {
+        MapConfig mapConfig = new MapConfig();
+
+        /*
+        Number of backups. If 1 is set as the backup-count for example,
+        then all entries of the map will be copied to another JVM for
+        fail-safety. Valid numbers are 0 (no backup), 1, 2, 3.
+        */
+        mapConfig.setBackupCount(jHipsterProperties.getCache().getHazelcast().getBackupCount());
+
+        /*
+        Valid values are:
+        NONE (no eviction),
+        LRU (Least Recently Used),
+        LFU (Least Frequently Used).
+        NONE is the default.
+        */
+        mapConfig.setEvictionPolicy(EvictionPolicy.LRU);
+
+        /*
+        Maximum size of the map. When max size is reached,
+        map is evicted based on the policy defined.
+        Any integer between 0 and Integer.MAX_VALUE. 0 means
+        Integer.MAX_VALUE. Default is 0.
+        */
+        mapConfig.setMaxSizeConfig(new MaxSizeConfig(0, MaxSizeConfig.MaxSizePolicy.USED_HEAP_SIZE));
+
+        return mapConfig;
+    }
+
+    private MapConfig initializeDomainMapConfig(JHipsterProperties jHipsterProperties) {
+        MapConfig mapConfig = new MapConfig();
+        mapConfig.setTimeToLiveSeconds(jHipsterProperties.getCache().getHazelcast().getTimeToLiveSeconds());
+        return mapConfig;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/CloudDatabaseConfiguration.java

@@ -0,0 +1,24 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.config.JHipsterConstants;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cache.CacheManager;
+import org.springframework.cloud.config.java.AbstractCloudConfig;
+import org.springframework.context.annotation.*;
+
+import javax.sql.DataSource;
+
+@Configuration
+@Profile(JHipsterConstants.SPRING_PROFILE_CLOUD)
+public class CloudDatabaseConfiguration extends AbstractCloudConfig {
+
+    private final Logger log = LoggerFactory.getLogger(CloudDatabaseConfiguration.class);
+
+    @Bean
+    public DataSource dataSource(CacheManager cacheManager) {
+        log.info("Configuring JDBC datasource from a cloud provider");
+        return connectionFactory().dataSource();
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/Constants.java

@@ -0,0 +1,17 @@
+package com.baeldung.jhipster.gateway.config;
+
+/**
+ * Application constants.
+ */
+public final class Constants {
+
+    // Regex for acceptable logins
+    public static final String LOGIN_REGEX = "^[_.@A-Za-z0-9-]*$";
+
+    public static final String SYSTEM_ACCOUNT = "system";
+    public static final String ANONYMOUS_USER = "anonymoususer";
+    public static final String DEFAULT_LANGUAGE = "en";
+    
+    private Constants() {
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/DatabaseConfiguration.java

@@ -0,0 +1,39 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.config.JHipsterConstants;
+import io.github.jhipster.config.h2.H2ConfigurationHelper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+
+import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import java.sql.SQLException;
+
+@Configuration
+@EnableJpaRepositories("com.baeldung.jhipster.gateway.repository")
+@EnableJpaAuditing(auditorAwareRef = "springSecurityAuditorAware")
+@EnableTransactionManagement
+public class DatabaseConfiguration {
+
+    private final Logger log = LoggerFactory.getLogger(DatabaseConfiguration.class);
+
+
+    /**
+     * Open the TCP port for the H2 database, so it is available remotely.
+     *
+     * @return the H2 database TCP server
+     * @throws SQLException if the server failed to start
+     */
+    @Bean(initMethod = "start", destroyMethod = "stop")
+    @Profile(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT)
+    public Object h2TCPServer() throws SQLException {
+        log.debug("Starting H2 database");
+        return H2ConfigurationHelper.createServer();
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/DateTimeFormatConfiguration.java

@@ -0,0 +1,20 @@
+package com.baeldung.jhipster.gateway.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.format.FormatterRegistry;
+import org.springframework.format.datetime.standard.DateTimeFormatterRegistrar;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+/**
+ * Configure the converters to use the ISO format for dates by default.
+ */
+@Configuration
+public class DateTimeFormatConfiguration implements WebMvcConfigurer {
+
+    @Override
+    public void addFormatters(FormatterRegistry registry) {
+        DateTimeFormatterRegistrar registrar = new DateTimeFormatterRegistrar();
+        registrar.setUseIsoFormat(true);
+        registrar.registerFormatters(registry);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/DefaultProfileUtil.java

@@ -0,0 +1,51 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.config.JHipsterConstants;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.core.env.Environment;
+
+import java.util.*;
+
+/**
+ * Utility class to load a Spring profile to be used as default
+ * when there is no <code>spring.profiles.active</code> set in the environment or as command line argument.
+ * If the value is not available in <code>application.yml</code> then <code>dev</code> profile will be used as default.
+ */
+public final class DefaultProfileUtil {
+
+    private static final String SPRING_PROFILE_DEFAULT = "spring.profiles.default";
+
+    private DefaultProfileUtil() {
+    }
+
+    /**
+     * Set a default to use when no profile is configured.
+     *
+     * @param app the Spring application
+     */
+    public static void addDefaultProfile(SpringApplication app) {
+        Map<String, Object> defProperties = new HashMap<>();
+        /*
+        * The default profile to use when no other profiles are defined
+        * This cannot be set in the <code>application.yml</code> file.
+        * See https://github.com/spring-projects/spring-boot/issues/1219
+        */
+        defProperties.put(SPRING_PROFILE_DEFAULT, JHipsterConstants.SPRING_PROFILE_DEVELOPMENT);
+        app.setDefaultProperties(defProperties);
+    }
+
+    /**
+     * Get the profiles that are applied else get default profiles.
+     *
+     * @param env spring environment
+     * @return profiles
+     */
+    public static String[] getActiveProfiles(Environment env) {
+        String[] profiles = env.getActiveProfiles();
+        if (profiles.length == 0) {
+            return env.getDefaultProfiles();
+        }
+        return profiles;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/GatewayConfiguration.java

@@ -0,0 +1,55 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.config.JHipsterProperties;
+
+import com.baeldung.jhipster.gateway.gateway.ratelimiting.RateLimitingFilter;
+import com.baeldung.jhipster.gateway.gateway.accesscontrol.AccessControlFilter;
+import com.baeldung.jhipster.gateway.gateway.responserewriting.SwaggerBasePathRewritingFilter;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.cloud.netflix.zuul.filters.RouteLocator;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class GatewayConfiguration {
+
+    @Configuration
+    public static class SwaggerBasePathRewritingConfiguration {
+
+        @Bean
+        public SwaggerBasePathRewritingFilter swaggerBasePathRewritingFilter(){
+            return new SwaggerBasePathRewritingFilter();
+        }
+    }
+
+    @Configuration
+    public static class AccessControlFilterConfiguration {
+
+        @Bean
+        public AccessControlFilter accessControlFilter(RouteLocator routeLocator, JHipsterProperties jHipsterProperties){
+            return new AccessControlFilter(routeLocator, jHipsterProperties);
+        }
+    }
+
+    /**
+     * Configures the Zuul filter that limits the number of API calls per user.
+     * <p>
+     * This uses Bucket4J to limit the API calls, see {@link com.baeldung.jhipster.gateway.gateway.ratelimiting.RateLimitingFilter}.
+     */
+    @Configuration
+    @ConditionalOnProperty("jhipster.gateway.rate-limiting.enabled")
+    public static class RateLimitingConfiguration {
+
+        private final JHipsterProperties jHipsterProperties;
+
+        public RateLimitingConfiguration(JHipsterProperties jHipsterProperties) {
+            this.jHipsterProperties = jHipsterProperties;
+        }
+
+        @Bean
+        public RateLimitingFilter rateLimitingFilter() {
+            return new RateLimitingFilter(jHipsterProperties);
+        }
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/JacksonConfiguration.java

@@ -0,0 +1,63 @@
+package com.baeldung.jhipster.gateway.config;
+
+import com.fasterxml.jackson.datatype.hibernate5.Hibernate5Module;
+import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.fasterxml.jackson.module.afterburner.AfterburnerModule;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.zalando.problem.ProblemModule;
+import org.zalando.problem.violations.ConstraintViolationProblemModule;
+
+@Configuration
+public class JacksonConfiguration {
+
+    /**
+     * Support for Java date and time API.
+     * @return the corresponding Jackson module.
+     */
+    @Bean
+    public JavaTimeModule javaTimeModule() {
+        return new JavaTimeModule();
+    }
+
+    @Bean
+    public Jdk8Module jdk8TimeModule() {
+        return new Jdk8Module();
+    }
+
+
+    /*
+     * Support for Hibernate types in Jackson.
+     */
+    @Bean
+    public Hibernate5Module hibernate5Module() {
+        return new Hibernate5Module();
+    }
+
+    /*
+     * Jackson Afterburner module to speed up serialization/deserialization.
+     */
+    @Bean
+    public AfterburnerModule afterburnerModule() {
+        return new AfterburnerModule();
+    }
+
+    /*
+     * Module for serialization/deserialization of RFC7807 Problem.
+     */
+    @Bean
+    ProblemModule problemModule() {
+        return new ProblemModule();
+    }
+
+    /*
+     * Module for serialization/deserialization of ConstraintViolationProblem.
+     */
+    @Bean
+    ConstraintViolationProblemModule constraintViolationProblemModule() {
+        return new ConstraintViolationProblemModule();
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/LiquibaseConfiguration.java

@@ -0,0 +1,53 @@
+package com.baeldung.jhipster.gateway.config;
+
+import javax.sql.DataSource;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.boot.autoconfigure.liquibase.LiquibaseProperties;
+import org.springframework.cache.CacheManager;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+import org.springframework.core.task.TaskExecutor;
+
+import io.github.jhipster.config.JHipsterConstants;
+import io.github.jhipster.config.liquibase.AsyncSpringLiquibase;
+import liquibase.integration.spring.SpringLiquibase;
+
+@Configuration
+public class LiquibaseConfiguration {
+
+    private final Logger log = LoggerFactory.getLogger(LiquibaseConfiguration.class);
+
+    private final Environment env;
+
+    private final CacheManager cacheManager;
+
+    public LiquibaseConfiguration(Environment env, CacheManager cacheManager) {
+        this.env = env;
+        this.cacheManager = cacheManager;
+    }
+
+    @Bean
+    public SpringLiquibase liquibase(@Qualifier("taskExecutor") TaskExecutor taskExecutor,
+            DataSource dataSource, LiquibaseProperties liquibaseProperties) {
+
+        // Use liquibase.integration.spring.SpringLiquibase if you don't want Liquibase to start asynchronously
+        SpringLiquibase liquibase = new AsyncSpringLiquibase(taskExecutor, env);
+        liquibase.setDataSource(dataSource);
+        liquibase.setChangeLog("classpath:config/liquibase/master.xml");
+        liquibase.setContexts(liquibaseProperties.getContexts());
+        liquibase.setDefaultSchema(liquibaseProperties.getDefaultSchema());
+        liquibase.setDropFirst(liquibaseProperties.isDropFirst());
+        liquibase.setChangeLogParameters(liquibaseProperties.getParameters());
+        if (env.acceptsProfiles(JHipsterConstants.SPRING_PROFILE_NO_LIQUIBASE)) {
+            liquibase.setShouldRun(false);
+        } else {
+            liquibase.setShouldRun(liquibaseProperties.isEnabled());
+            log.debug("Configuring Liquibase");
+        }
+        return liquibase;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/LocaleConfiguration.java

@@ -0,0 +1,27 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.config.locale.AngularCookieLocaleResolver;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.LocaleResolver;
+import org.springframework.web.servlet.config.annotation.*;
+import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
+
+@Configuration
+public class LocaleConfiguration implements WebMvcConfigurer {
+
+    @Bean(name = "localeResolver")
+    public LocaleResolver localeResolver() {
+        AngularCookieLocaleResolver cookieLocaleResolver = new AngularCookieLocaleResolver();
+        cookieLocaleResolver.setCookieName("NG_TRANSLATE_LANG_KEY");
+        return cookieLocaleResolver;
+    }
+
+    @Override
+    public void addInterceptors(InterceptorRegistry registry) {
+        LocaleChangeInterceptor localeChangeInterceptor = new LocaleChangeInterceptor();
+        localeChangeInterceptor.setParamName("language");
+        registry.addInterceptor(localeChangeInterceptor);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/LoggingAspectConfiguration.java

@@ -0,0 +1,19 @@
+package com.baeldung.jhipster.gateway.config;
+
+import com.baeldung.jhipster.gateway.aop.logging.LoggingAspect;
+
+import io.github.jhipster.config.JHipsterConstants;
+
+import org.springframework.context.annotation.*;
+import org.springframework.core.env.Environment;
+
+@Configuration
+@EnableAspectJAutoProxy
+public class LoggingAspectConfiguration {
+
+    @Bean
+    @Profile(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT)
+    public LoggingAspect loggingAspect(Environment env) {
+        return new LoggingAspect(env);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/LoggingConfiguration.java

@@ -0,0 +1,163 @@
+package com.baeldung.jhipster.gateway.config;
+
+import java.net.InetSocketAddress;
+import java.util.Iterator;
+
+import io.github.jhipster.config.JHipsterProperties;
+
+import ch.qos.logback.classic.AsyncAppender;
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.LoggerContext;
+import ch.qos.logback.classic.boolex.OnMarkerEvaluator;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.classic.spi.LoggerContextListener;
+import ch.qos.logback.core.Appender;
+import ch.qos.logback.core.filter.EvaluatorFilter;
+import ch.qos.logback.core.spi.ContextAwareBase;
+import ch.qos.logback.core.spi.FilterReply;
+import net.logstash.logback.appender.LogstashTcpSocketAppender;
+import net.logstash.logback.encoder.LogstashEncoder;
+import net.logstash.logback.stacktrace.ShortenedThrowableConverter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.cloud.context.config.annotation.RefreshScope;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@RefreshScope
+public class LoggingConfiguration {
+
+    private static final String LOGSTASH_APPENDER_NAME = "LOGSTASH";
+
+    private static final String ASYNC_LOGSTASH_APPENDER_NAME = "ASYNC_LOGSTASH";
+
+    private final Logger log = LoggerFactory.getLogger(LoggingConfiguration.class);
+
+    private LoggerContext context = (LoggerContext) LoggerFactory.getILoggerFactory();
+
+    private final String appName;
+
+    private final String serverPort;
+
+    private final String version;
+
+    private final JHipsterProperties jHipsterProperties;
+
+    public LoggingConfiguration(@Value("${spring.application.name}") String appName, @Value("${server.port}") String serverPort,
+         @Value("${info.project.version:}") String version, JHipsterProperties jHipsterProperties) {
+        this.appName = appName;
+        this.serverPort = serverPort;
+        this.version = version;
+        this.jHipsterProperties = jHipsterProperties;
+        if (jHipsterProperties.getLogging().getLogstash().isEnabled()) {
+            addLogstashAppender(context);
+            addContextListener(context);
+        }
+        if (jHipsterProperties.getMetrics().getLogs().isEnabled()) {
+            setMetricsMarkerLogbackFilter(context);
+        }
+    }
+
+    private void addContextListener(LoggerContext context) {
+        LogbackLoggerContextListener loggerContextListener = new LogbackLoggerContextListener();
+        loggerContextListener.setContext(context);
+        context.addListener(loggerContextListener);
+    }
+
+    private void addLogstashAppender(LoggerContext context) {
+        log.info("Initializing Logstash logging");
+
+        LogstashTcpSocketAppender logstashAppender = new LogstashTcpSocketAppender();
+        logstashAppender.setName(LOGSTASH_APPENDER_NAME);
+        logstashAppender.setContext(context);
+        String optionalFields = "";
+        String customFields = "{\"app_name\":\"" + appName + "\",\"app_port\":\"" + serverPort + "\"," +
+            optionalFields + "\"version\":\"" + version + "\"}";
+
+        // More documentation is available at: https://github.com/logstash/logstash-logback-encoder
+        LogstashEncoder logstashEncoder = new LogstashEncoder();
+        // Set the Logstash appender config from JHipster properties
+        logstashEncoder.setCustomFields(customFields);
+        // Set the Logstash appender config from JHipster properties
+        logstashAppender.addDestinations(new InetSocketAddress(jHipsterProperties.getLogging().getLogstash().getHost(), jHipsterProperties.getLogging().getLogstash().getPort()));
+
+        ShortenedThrowableConverter throwableConverter = new ShortenedThrowableConverter();
+        throwableConverter.setRootCauseFirst(true);
+        logstashEncoder.setThrowableConverter(throwableConverter);
+        logstashEncoder.setCustomFields(customFields);
+
+        logstashAppender.setEncoder(logstashEncoder);
+        logstashAppender.start();
+
+        // Wrap the appender in an Async appender for performance
+        AsyncAppender asyncLogstashAppender = new AsyncAppender();
+        asyncLogstashAppender.setContext(context);
+        asyncLogstashAppender.setName(ASYNC_LOGSTASH_APPENDER_NAME);
+        asyncLogstashAppender.setQueueSize(jHipsterProperties.getLogging().getLogstash().getQueueSize());
+        asyncLogstashAppender.addAppender(logstashAppender);
+        asyncLogstashAppender.start();
+
+        context.getLogger("ROOT").addAppender(asyncLogstashAppender);
+    }
+
+    // Configure a log filter to remove "metrics" logs from all appenders except the "LOGSTASH" appender
+    private void setMetricsMarkerLogbackFilter(LoggerContext context) {
+        log.info("Filtering metrics logs from all appenders except the {} appender", LOGSTASH_APPENDER_NAME);
+        OnMarkerEvaluator onMarkerMetricsEvaluator = new OnMarkerEvaluator();
+        onMarkerMetricsEvaluator.setContext(context);
+        onMarkerMetricsEvaluator.addMarker("metrics");
+        onMarkerMetricsEvaluator.start();
+        EvaluatorFilter<ILoggingEvent> metricsFilter = new EvaluatorFilter<>();
+        metricsFilter.setContext(context);
+        metricsFilter.setEvaluator(onMarkerMetricsEvaluator);
+        metricsFilter.setOnMatch(FilterReply.DENY);
+        metricsFilter.start();
+
+        for (ch.qos.logback.classic.Logger logger : context.getLoggerList()) {
+            for (Iterator<Appender<ILoggingEvent>> it = logger.iteratorForAppenders(); it.hasNext();) {
+                Appender<ILoggingEvent> appender = it.next();
+                if (!appender.getName().equals(ASYNC_LOGSTASH_APPENDER_NAME)) {
+                    log.debug("Filter metrics logs from the {} appender", appender.getName());
+                    appender.setContext(context);
+                    appender.addFilter(metricsFilter);
+                    appender.start();
+                }
+            }
+        }
+    }
+
+    /**
+     * Logback configuration is achieved by configuration file and API.
+     * When configuration file change is detected, the configuration is reset.
+     * This listener ensures that the programmatic configuration is also re-applied after reset.
+     */
+    class LogbackLoggerContextListener extends ContextAwareBase implements LoggerContextListener {
+
+        @Override
+        public boolean isResetResistant() {
+            return true;
+        }
+
+        @Override
+        public void onStart(LoggerContext context) {
+            addLogstashAppender(context);
+        }
+
+        @Override
+        public void onReset(LoggerContext context) {
+            addLogstashAppender(context);
+        }
+
+        @Override
+        public void onStop(LoggerContext context) {
+            // Nothing to do.
+        }
+
+        @Override
+        public void onLevelChange(ch.qos.logback.classic.Logger logger, Level level) {
+            // Nothing to do.
+        }
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/MetricsConfiguration.java

@@ -0,0 +1,99 @@
+package com.baeldung.jhipster.gateway.config;
+
+import io.github.jhipster.config.JHipsterProperties;
+
+import com.codahale.metrics.JmxReporter;
+import com.codahale.metrics.JvmAttributeGaugeSet;
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.Slf4jReporter;
+import com.codahale.metrics.health.HealthCheckRegistry;
+import com.codahale.metrics.jvm.*;
+import com.ryantenney.metrics.spring.config.annotation.EnableMetrics;
+import com.ryantenney.metrics.spring.config.annotation.MetricsConfigurerAdapter;
+import com.zaxxer.hikari.HikariDataSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.slf4j.Marker;
+import org.slf4j.MarkerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.*;
+
+import javax.annotation.PostConstruct;
+import java.lang.management.ManagementFactory;
+import java.util.concurrent.TimeUnit;
+
+@Configuration
+@EnableMetrics(proxyTargetClass = true)
+public class MetricsConfiguration extends MetricsConfigurerAdapter {
+
+    private static final String PROP_METRIC_REG_JVM_MEMORY = "jvm.memory";
+    private static final String PROP_METRIC_REG_JVM_GARBAGE = "jvm.garbage";
+    private static final String PROP_METRIC_REG_JVM_THREADS = "jvm.threads";
+    private static final String PROP_METRIC_REG_JVM_FILES = "jvm.files";
+    private static final String PROP_METRIC_REG_JVM_BUFFERS = "jvm.buffers";
+    private static final String PROP_METRIC_REG_JVM_ATTRIBUTE_SET = "jvm.attributes";
+
+    private final Logger log = LoggerFactory.getLogger(MetricsConfiguration.class);
+
+    private MetricRegistry metricRegistry = new MetricRegistry();
+
+    private HealthCheckRegistry healthCheckRegistry = new HealthCheckRegistry();
+
+    private final JHipsterProperties jHipsterProperties;
+
+    private HikariDataSource hikariDataSource;
+
+    public MetricsConfiguration(JHipsterProperties jHipsterProperties) {
+        this.jHipsterProperties = jHipsterProperties;
+    }
+
+    @Autowired(required = false)
+    public void setHikariDataSource(HikariDataSource hikariDataSource) {
+        this.hikariDataSource = hikariDataSource;
+    }
+
+    @Override
+    @Bean
+    public MetricRegistry getMetricRegistry() {
+        return metricRegistry;
+    }
+
+    @Override
+    @Bean
+    public HealthCheckRegistry getHealthCheckRegistry() {
+        return healthCheckRegistry;
+    }
+
+    @PostConstruct
+    public void init() {
+        log.debug("Registering JVM gauges");
+        metricRegistry.register(PROP_METRIC_REG_JVM_MEMORY, new MemoryUsageGaugeSet());
+        metricRegistry.register(PROP_METRIC_REG_JVM_GARBAGE, new GarbageCollectorMetricSet());
+        metricRegistry.register(PROP_METRIC_REG_JVM_THREADS, new ThreadStatesGaugeSet());
+        metricRegistry.register(PROP_METRIC_REG_JVM_FILES, new FileDescriptorRatioGauge());
+        metricRegistry.register(PROP_METRIC_REG_JVM_BUFFERS, new BufferPoolMetricSet(ManagementFactory.getPlatformMBeanServer()));
+        metricRegistry.register(PROP_METRIC_REG_JVM_ATTRIBUTE_SET, new JvmAttributeGaugeSet());
+        if (hikariDataSource != null) {
+            log.debug("Monitoring the datasource");
+            // remove the factory created by HikariDataSourceMetricsPostProcessor until JHipster migrate to Micrometer
+            hikariDataSource.setMetricsTrackerFactory(null);
+            hikariDataSource.setMetricRegistry(metricRegistry);
+        }
+        if (jHipsterProperties.getMetrics().getJmx().isEnabled()) {
+            log.debug("Initializing Metrics JMX reporting");
+            JmxReporter jmxReporter = JmxReporter.forRegistry(metricRegistry).build();
+            jmxReporter.start();
+        }
+        if (jHipsterProperties.getMetrics().getLogs().isEnabled()) {
+            log.info("Initializing Metrics Log reporting");
+            Marker metricsMarker = MarkerFactory.getMarker("metrics");
+            final Slf4jReporter reporter = Slf4jReporter.forRegistry(metricRegistry)
+                .outputTo(LoggerFactory.getLogger("metrics"))
+                .markWith(metricsMarker)
+                .convertRatesTo(TimeUnit.SECONDS)
+                .convertDurationsTo(TimeUnit.MILLISECONDS)
+                .build();
+            reporter.start(jHipsterProperties.getMetrics().getLogs().getReportFrequency(), TimeUnit.SECONDS);
+        }
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/SecurityConfiguration.java

@@ -0,0 +1,83 @@
+package com.baeldung.jhipster.gateway.config;
+
+import com.baeldung.jhipster.gateway.config.oauth2.OAuth2JwtAccessTokenConverter;
+import com.baeldung.jhipster.gateway.config.oauth2.OAuth2Properties;
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2SignatureVerifierClient;
+import com.baeldung.jhipster.gateway.security.AuthoritiesConstants;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.cloud.client.loadbalancer.RestTemplateCustomizer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.http.SessionCreationPolicy;
+import org.springframework.security.oauth2.config.annotation.web.configuration.EnableResourceServer;
+import org.springframework.security.oauth2.config.annotation.web.configuration.ResourceServerConfigurerAdapter;
+import org.springframework.security.oauth2.provider.token.TokenStore;
+import org.springframework.security.oauth2.provider.token.store.JwtAccessTokenConverter;
+import org.springframework.security.oauth2.provider.token.store.JwtTokenStore;
+import org.springframework.security.web.csrf.CookieCsrfTokenRepository;
+import org.springframework.security.web.csrf.CsrfFilter;
+import org.springframework.web.filter.CorsFilter;
+import org.springframework.web.client.RestTemplate;
+
+@Configuration
+@EnableResourceServer
+@EnableGlobalMethodSecurity(prePostEnabled = true, securedEnabled = true)
+public class SecurityConfiguration extends ResourceServerConfigurerAdapter {
+    private final OAuth2Properties oAuth2Properties;
+
+    private final CorsFilter corsFilter;
+
+    public SecurityConfiguration(OAuth2Properties oAuth2Properties, CorsFilter corsFilter) {
+        this.oAuth2Properties = oAuth2Properties;
+        this.corsFilter = corsFilter;
+    }
+
+    @Override
+    public void configure(HttpSecurity http) throws Exception {
+        http
+            .csrf()
+            .ignoringAntMatchers("/h2-console/**")
+            .csrfTokenRepository(CookieCsrfTokenRepository.withHttpOnlyFalse())
+        .and()
+            .addFilterBefore(corsFilter, CsrfFilter.class)
+            .headers()
+            .frameOptions()
+            .disable()
+        .and()
+            .sessionManagement()
+            .sessionCreationPolicy(SessionCreationPolicy.STATELESS)
+        .and()
+            .authorizeRequests()
+            .antMatchers("/api/**").authenticated()
+            .antMatchers("/management/health").permitAll()
+            .antMatchers("/management/info").permitAll()
+            .antMatchers("/management/**").hasAuthority(AuthoritiesConstants.ADMIN);
+    }
+
+    @Bean
+    public TokenStore tokenStore(JwtAccessTokenConverter jwtAccessTokenConverter) {
+        return new JwtTokenStore(jwtAccessTokenConverter);
+    }
+
+    @Bean
+    public JwtAccessTokenConverter jwtAccessTokenConverter(OAuth2SignatureVerifierClient signatureVerifierClient) {
+        return new OAuth2JwtAccessTokenConverter(oAuth2Properties, signatureVerifierClient);
+    }
+
+    @Bean
+	@Qualifier("loadBalancedRestTemplate")
+    public RestTemplate loadBalancedRestTemplate(RestTemplateCustomizer customizer) {
+        RestTemplate restTemplate = new RestTemplate();
+        customizer.customize(restTemplate);
+        return restTemplate;
+    }
+
+    @Bean
+    @Qualifier("vanillaRestTemplate")
+    public RestTemplate vanillaRestTemplate() {
+        return new RestTemplate();
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/WebConfigurer.java

@@ -0,0 +1,210 @@
+package com.baeldung.jhipster.gateway.config;
+
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.servlet.InstrumentedFilter;
+import com.codahale.metrics.servlets.MetricsServlet;
+import io.github.jhipster.config.JHipsterConstants;
+import io.github.jhipster.config.JHipsterProperties;
+import io.github.jhipster.config.h2.H2ConfigurationHelper;
+import io.github.jhipster.web.filter.CachingHttpHeadersFilter;
+import io.undertow.UndertowOptions;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.web.embedded.undertow.UndertowServletWebServerFactory;
+import org.springframework.boot.web.server.*;
+import org.springframework.boot.web.servlet.ServletContextInitializer;
+import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+import org.springframework.http.MediaType;
+import org.springframework.web.cors.CorsConfiguration;
+import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
+import org.springframework.web.filter.CorsFilter;
+
+import javax.servlet.*;
+import java.io.File;
+import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Paths;
+import java.util.*;
+
+import static java.net.URLDecoder.decode;
+
+/**
+ * Configuration of web application with Servlet 3.0 APIs.
+ */
+@Configuration
+public class WebConfigurer implements ServletContextInitializer, WebServerFactoryCustomizer<WebServerFactory> {
+
+    private final Logger log = LoggerFactory.getLogger(WebConfigurer.class);
+
+    private final Environment env;
+
+    private final JHipsterProperties jHipsterProperties;
+
+    private MetricRegistry metricRegistry;
+
+    public WebConfigurer(Environment env, JHipsterProperties jHipsterProperties) {
+
+        this.env = env;
+        this.jHipsterProperties = jHipsterProperties;
+    }
+
+    @Override
+    public void onStartup(ServletContext servletContext) throws ServletException {
+        if (env.getActiveProfiles().length != 0) {
+            log.info("Web application configuration, using profiles: {}", (Object[]) env.getActiveProfiles());
+        }
+        EnumSet<DispatcherType> disps = EnumSet.of(DispatcherType.REQUEST, DispatcherType.FORWARD, DispatcherType.ASYNC);
+        initMetrics(servletContext, disps);
+        if (env.acceptsProfiles(JHipsterConstants.SPRING_PROFILE_PRODUCTION)) {
+            initCachingHttpHeadersFilter(servletContext, disps);
+        }
+        if (env.acceptsProfiles(JHipsterConstants.SPRING_PROFILE_DEVELOPMENT)) {
+            initH2Console(servletContext);
+        }
+        log.info("Web application fully configured");
+    }
+
+    /**
+     * Customize the Servlet engine: Mime types, the document root, the cache.
+     */
+    @Override
+    public void customize(WebServerFactory server) {
+        setMimeMappings(server);
+        // When running in an IDE or with ./mvnw spring-boot:run, set location of the static web assets.
+        setLocationForStaticAssets(server);
+
+        /*
+         * Enable HTTP/2 for Undertow - https://twitter.com/ankinson/status/829256167700492288
+         * HTTP/2 requires HTTPS, so HTTP requests will fallback to HTTP/1.1.
+         * See the JHipsterProperties class and your application-*.yml configuration files
+         * for more information.
+         */
+        if (jHipsterProperties.getHttp().getVersion().equals(JHipsterProperties.Http.Version.V_2_0) &&
+            server instanceof UndertowServletWebServerFactory) {
+
+            ((UndertowServletWebServerFactory) server)
+                .addBuilderCustomizers(builder ->
+                    builder.setServerOption(UndertowOptions.ENABLE_HTTP2, true));
+        }
+    }
+
+    private void setMimeMappings(WebServerFactory server) {
+        if (server instanceof ConfigurableServletWebServerFactory) {
+            MimeMappings mappings = new MimeMappings(MimeMappings.DEFAULT);
+            // IE issue, see https://github.com/jhipster/generator-jhipster/pull/711
+            mappings.add("html", MediaType.TEXT_HTML_VALUE + ";charset=" + StandardCharsets.UTF_8.name().toLowerCase());
+            // CloudFoundry issue, see https://github.com/cloudfoundry/gorouter/issues/64
+            mappings.add("json", MediaType.TEXT_HTML_VALUE + ";charset=" + StandardCharsets.UTF_8.name().toLowerCase());
+            ConfigurableServletWebServerFactory servletWebServer = (ConfigurableServletWebServerFactory) server;
+            servletWebServer.setMimeMappings(mappings);
+        }
+    }
+
+    private void setLocationForStaticAssets(WebServerFactory server) {
+        if (server instanceof ConfigurableServletWebServerFactory) {
+            ConfigurableServletWebServerFactory servletWebServer = (ConfigurableServletWebServerFactory) server;
+            File root;
+            String prefixPath = resolvePathPrefix();
+            root = new File(prefixPath + "target/www/");
+            if (root.exists() && root.isDirectory()) {
+                servletWebServer.setDocumentRoot(root);
+            }
+        }
+    }
+
+    /**
+     * Resolve path prefix to static resources.
+     */
+    private String resolvePathPrefix() {
+        String fullExecutablePath;
+        try {
+            fullExecutablePath = decode(this.getClass().getResource("").getPath(), StandardCharsets.UTF_8.name());
+        } catch (UnsupportedEncodingException e) {
+            /* try without decoding if this ever happens */
+            fullExecutablePath = this.getClass().getResource("").getPath();
+        }
+        String rootPath = Paths.get(".").toUri().normalize().getPath();
+        String extractedPath = fullExecutablePath.replace(rootPath, "");
+        int extractionEndIndex = extractedPath.indexOf("target/");
+        if (extractionEndIndex <= 0) {
+            return "";
+        }
+        return extractedPath.substring(0, extractionEndIndex);
+    }
+
+    /**
+     * Initializes the caching HTTP Headers Filter.
+     */
+    private void initCachingHttpHeadersFilter(ServletContext servletContext,
+                                              EnumSet<DispatcherType> disps) {
+        log.debug("Registering Caching HTTP Headers Filter");
+        FilterRegistration.Dynamic cachingHttpHeadersFilter =
+            servletContext.addFilter("cachingHttpHeadersFilter",
+                new CachingHttpHeadersFilter(jHipsterProperties));
+
+        cachingHttpHeadersFilter.addMappingForUrlPatterns(disps, true, "/i18n/*");
+        cachingHttpHeadersFilter.addMappingForUrlPatterns(disps, true, "/content/*");
+        cachingHttpHeadersFilter.addMappingForUrlPatterns(disps, true, "/app/*");
+        cachingHttpHeadersFilter.setAsyncSupported(true);
+    }
+
+    /**
+     * Initializes Metrics.
+     */
+    private void initMetrics(ServletContext servletContext, EnumSet<DispatcherType> disps) {
+        log.debug("Initializing Metrics registries");
+        servletContext.setAttribute(InstrumentedFilter.REGISTRY_ATTRIBUTE,
+            metricRegistry);
+        servletContext.setAttribute(MetricsServlet.METRICS_REGISTRY,
+            metricRegistry);
+
+        log.debug("Registering Metrics Filter");
+        FilterRegistration.Dynamic metricsFilter = servletContext.addFilter("webappMetricsFilter",
+            new InstrumentedFilter());
+
+        metricsFilter.addMappingForUrlPatterns(disps, true, "/*");
+        metricsFilter.setAsyncSupported(true);
+
+        log.debug("Registering Metrics Servlet");
+        ServletRegistration.Dynamic metricsAdminServlet =
+            servletContext.addServlet("metricsServlet", new MetricsServlet());
+
+        metricsAdminServlet.addMapping("/management/metrics/*");
+        metricsAdminServlet.setAsyncSupported(true);
+        metricsAdminServlet.setLoadOnStartup(2);
+    }
+
+    @Bean
+    public CorsFilter corsFilter() {
+        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
+        CorsConfiguration config = jHipsterProperties.getCors();
+        if (config.getAllowedOrigins() != null && !config.getAllowedOrigins().isEmpty()) {
+            log.debug("Registering CORS filter");
+            source.registerCorsConfiguration("/api/**", config);
+            source.registerCorsConfiguration("/management/**", config);
+            source.registerCorsConfiguration("/v2/api-docs", config);
+            source.registerCorsConfiguration("/auth/**", config);
+            source.registerCorsConfiguration("/*/api/**", config);
+            source.registerCorsConfiguration("/*/management/**", config);
+            source.registerCorsConfiguration("/*/oauth/**", config);
+        }
+        return new CorsFilter(source);
+    }
+
+    /**
+     * Initializes H2 console.
+     */
+    private void initH2Console(ServletContext servletContext) {
+        log.debug("Initialize H2 console");
+        H2ConfigurationHelper.initH2Console(servletContext);
+    }
+
+    @Autowired(required = false)
+    public void setMetricRegistry(MetricRegistry metricRegistry) {
+        this.metricRegistry = metricRegistry;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/apidoc/GatewaySwaggerResourcesProvider.java

@@ -0,0 +1,54 @@
+package com.baeldung.jhipster.gateway.config.apidoc;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import io.github.jhipster.config.JHipsterConstants;
+
+import org.springframework.context.annotation.*;
+import org.springframework.cloud.netflix.zuul.filters.Route;
+import org.springframework.cloud.netflix.zuul.filters.RouteLocator;
+import org.springframework.context.annotation.Primary;
+import org.springframework.stereotype.Component;
+
+import springfox.documentation.swagger.web.SwaggerResource;
+import springfox.documentation.swagger.web.SwaggerResourcesProvider;
+
+/**
+ * Retrieves all registered microservices Swagger resources.
+ */
+@Component
+@Primary
+@Profile(JHipsterConstants.SPRING_PROFILE_SWAGGER)
+public class GatewaySwaggerResourcesProvider implements SwaggerResourcesProvider {
+
+    private final RouteLocator routeLocator;
+
+    public GatewaySwaggerResourcesProvider(RouteLocator routeLocator) {
+        this.routeLocator = routeLocator;
+    }
+
+    @Override
+    public List<SwaggerResource> get() {
+        List<SwaggerResource> resources = new ArrayList<>();
+
+        //Add the default swagger resource that correspond to the gateway's own swagger doc
+        resources.add(swaggerResource("default", "/v2/api-docs"));
+
+        //Add the registered microservices swagger docs as additional swagger resources
+        List<Route> routes = routeLocator.getRoutes();
+        routes.forEach(route -> {
+            resources.add(swaggerResource(route.getId(), route.getFullPath().replace("**", "v2/api-docs")));
+        });
+
+        return resources;
+    }
+
+    private SwaggerResource swaggerResource(String name, String location) {
+        SwaggerResource swaggerResource = new SwaggerResource();
+        swaggerResource.setName(name);
+        swaggerResource.setLocation(location);
+        swaggerResource.setSwaggerVersion("2.0");
+        return swaggerResource;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/audit/AuditEventConverter.java

@@ -0,0 +1,86 @@
+package com.baeldung.jhipster.gateway.config.audit;
+
+import com.baeldung.jhipster.gateway.domain.PersistentAuditEvent;
+
+import org.springframework.boot.actuate.audit.AuditEvent;
+import org.springframework.security.web.authentication.WebAuthenticationDetails;
+import org.springframework.stereotype.Component;
+
+import java.util.*;
+
+@Component
+public class AuditEventConverter {
+
+    /**
+     * Convert a list of PersistentAuditEvent to a list of AuditEvent
+     *
+     * @param persistentAuditEvents the list to convert
+     * @return the converted list.
+     */
+    public List<AuditEvent> convertToAuditEvent(Iterable<PersistentAuditEvent> persistentAuditEvents) {
+        if (persistentAuditEvents == null) {
+            return Collections.emptyList();
+        }
+        List<AuditEvent> auditEvents = new ArrayList<>();
+        for (PersistentAuditEvent persistentAuditEvent : persistentAuditEvents) {
+            auditEvents.add(convertToAuditEvent(persistentAuditEvent));
+        }
+        return auditEvents;
+    }
+
+    /**
+     * Convert a PersistentAuditEvent to an AuditEvent
+     *
+     * @param persistentAuditEvent the event to convert
+     * @return the converted list.
+     */
+    public AuditEvent convertToAuditEvent(PersistentAuditEvent persistentAuditEvent) {
+        if (persistentAuditEvent == null) {
+            return null;
+        }
+        return new AuditEvent(persistentAuditEvent.getAuditEventDate(), persistentAuditEvent.getPrincipal(),
+            persistentAuditEvent.getAuditEventType(), convertDataToObjects(persistentAuditEvent.getData()));
+    }
+
+    /**
+     * Internal conversion. This is needed to support the current SpringBoot actuator AuditEventRepository interface
+     *
+     * @param data the data to convert
+     * @return a map of String, Object
+     */
+    public Map<String, Object> convertDataToObjects(Map<String, String> data) {
+        Map<String, Object> results = new HashMap<>();
+
+        if (data != null) {
+            for (Map.Entry<String, String> entry : data.entrySet()) {
+                results.put(entry.getKey(), entry.getValue());
+            }
+        }
+        return results;
+    }
+
+    /**
+     * Internal conversion. This method will allow to save additional data.
+     * By default, it will save the object as string
+     *
+     * @param data the data to convert
+     * @return a map of String, String
+     */
+    public Map<String, String> convertDataToStrings(Map<String, Object> data) {
+        Map<String, String> results = new HashMap<>();
+
+        if (data != null) {
+            for (Map.Entry<String, Object> entry : data.entrySet()) {
+                // Extract the data that will be saved.
+                if (entry.getValue() instanceof WebAuthenticationDetails) {
+                    WebAuthenticationDetails authenticationDetails = (WebAuthenticationDetails) entry.getValue();
+                    results.put("remoteAddress", authenticationDetails.getRemoteAddress());
+                    results.put("sessionId", authenticationDetails.getSessionId());
+                } else {
+                    results.put(entry.getKey(), Objects.toString(entry.getValue()));
+                }
+            }
+        }
+        return results;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/audit/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Audit specific code.
+ */
+package com.baeldung.jhipster.gateway.config.audit;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/oauth2/OAuth2AuthenticationConfiguration.java

@@ -0,0 +1,80 @@
+package com.baeldung.jhipster.gateway.config.oauth2;
+
+import com.baeldung.jhipster.gateway.security.oauth2.CookieTokenExtractor;
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2AuthenticationService;
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2CookieHelper;
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2TokenEndpointClient;
+import com.baeldung.jhipster.gateway.web.filter.RefreshTokenFilterConfigurer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.oauth2.config.annotation.web.configuration.EnableResourceServer;
+import org.springframework.security.oauth2.config.annotation.web.configuration.ResourceServerConfigurerAdapter;
+import org.springframework.security.oauth2.config.annotation.web.configurers.ResourceServerSecurityConfigurer;
+import org.springframework.security.oauth2.provider.authentication.TokenExtractor;
+import org.springframework.security.oauth2.provider.token.TokenStore;
+
+/**
+ * Configures the RefreshFilter refreshing expired OAuth2 token Cookies.
+ */
+@Configuration
+@EnableResourceServer
+@EnableGlobalMethodSecurity(prePostEnabled = true, securedEnabled = true)
+public class OAuth2AuthenticationConfiguration extends ResourceServerConfigurerAdapter {
+    private final OAuth2Properties oAuth2Properties;
+    private final OAuth2TokenEndpointClient tokenEndpointClient;
+    private final TokenStore tokenStore;
+
+    public OAuth2AuthenticationConfiguration(OAuth2Properties oAuth2Properties, OAuth2TokenEndpointClient tokenEndpointClient, TokenStore tokenStore) {
+        this.oAuth2Properties = oAuth2Properties;
+        this.tokenEndpointClient = tokenEndpointClient;
+        this.tokenStore = tokenStore;
+    }
+
+    @Override
+    public void configure(HttpSecurity http) throws Exception {
+        http
+            .authorizeRequests()
+            .antMatchers("/auth/login").permitAll()
+            .antMatchers("/auth/logout").authenticated()
+            .and()
+            .apply(refreshTokenSecurityConfigurerAdapter());
+    }
+
+    /**
+     * A SecurityConfigurerAdapter to install a servlet filter that refreshes OAuth2 tokens.
+     */
+    private RefreshTokenFilterConfigurer refreshTokenSecurityConfigurerAdapter() {
+        return new RefreshTokenFilterConfigurer(uaaAuthenticationService(), tokenStore);
+    }
+
+    @Bean
+    public OAuth2CookieHelper cookieHelper() {
+        return new OAuth2CookieHelper(oAuth2Properties);
+    }
+
+    @Bean
+    public OAuth2AuthenticationService uaaAuthenticationService() {
+        return new OAuth2AuthenticationService(tokenEndpointClient, cookieHelper());
+    }
+
+    /**
+     * Configure the ResourceServer security by installing a new TokenExtractor.
+     */
+    @Override
+    public void configure(ResourceServerSecurityConfigurer resources) throws Exception {
+        resources.tokenExtractor(tokenExtractor());
+    }
+
+    /**
+     * The new TokenExtractor can extract tokens from Cookies and Authorization headers.
+     *
+     * @return the CookieTokenExtractor bean.
+     */
+    @Bean
+    public TokenExtractor tokenExtractor() {
+        return new CookieTokenExtractor();
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/oauth2/OAuth2JwtAccessTokenConverter.java

@@ -0,0 +1,109 @@
+package com.baeldung.jhipster.gateway.config.oauth2;
+
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2SignatureVerifierClient;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.security.jwt.crypto.sign.SignatureVerifier;
+import org.springframework.security.oauth2.common.exceptions.InvalidTokenException;
+import org.springframework.security.oauth2.provider.token.store.JwtAccessTokenConverter;
+import org.springframework.security.oauth2.provider.OAuth2Authentication;
+
+import java.util.Map;
+
+/**
+ * Improved JwtAccessTokenConverter that can handle lazy fetching of public verifier keys.
+ */
+public class OAuth2JwtAccessTokenConverter extends JwtAccessTokenConverter {
+    private final Logger log = LoggerFactory.getLogger(OAuth2JwtAccessTokenConverter.class);
+
+    private final OAuth2Properties oAuth2Properties;
+    private final OAuth2SignatureVerifierClient signatureVerifierClient;
+    /**
+     * When did we last fetch the public key?
+     */
+    private long lastKeyFetchTimestamp;
+
+    public OAuth2JwtAccessTokenConverter(OAuth2Properties oAuth2Properties, OAuth2SignatureVerifierClient signatureVerifierClient) {
+        this.oAuth2Properties = oAuth2Properties;
+        this.signatureVerifierClient = signatureVerifierClient;
+        tryCreateSignatureVerifier();
+    }
+
+    /**
+     * Try to decode the token with the current public key.
+     * If it fails, contact the OAuth2 server to get a new public key, then try again.
+     * We might not have fetched it in the first place or it might have changed.
+     *
+     * @param token the JWT token to decode.
+     * @return the resulting claims.
+     * @throws InvalidTokenException if we cannot decode the token.
+     */
+    @Override
+    protected Map<String, Object> decode(String token) {
+        try {
+            //check if our public key and thus SignatureVerifier have expired
+            long ttl = oAuth2Properties.getSignatureVerification().getTtl();
+            if (ttl > 0 && System.currentTimeMillis() - lastKeyFetchTimestamp > ttl) {
+                throw new InvalidTokenException("public key expired");
+            }
+            return super.decode(token);
+        } catch (InvalidTokenException ex) {
+            if (tryCreateSignatureVerifier()) {
+                return super.decode(token);
+            }
+            throw ex;
+        }
+    }
+
+    /**
+     * Fetch a new public key from the AuthorizationServer.
+     *
+     * @return true, if we could fetch it; false, if we could not.
+     */
+    private boolean tryCreateSignatureVerifier() {
+        long t = System.currentTimeMillis();
+        if (t - lastKeyFetchTimestamp < oAuth2Properties.getSignatureVerification().getPublicKeyRefreshRateLimit()) {
+            return false;
+        }
+        try {
+            SignatureVerifier verifier = signatureVerifierClient.getSignatureVerifier();
+            if (verifier != null) {
+                setVerifier(verifier);
+                lastKeyFetchTimestamp = t;
+                log.debug("Public key retrieved from OAuth2 server to create SignatureVerifier");
+                return true;
+            }
+        } catch (Throwable ex) {
+            log.error("could not get public key from OAuth2 server to create SignatureVerifier", ex);
+        }
+        return false;
+    }
+    /**
+     * Extract JWT claims and set it to OAuth2Authentication decoded details.
+     * Here is how to get details:
+     *
+     * <pre>
+     * <code>
+     *  SecurityContext securityContext = SecurityContextHolder.getContext();
+     *  Authentication authentication = securityContext.getAuthentication();
+     *  if (authentication != null) {
+     *      Object details = authentication.getDetails();
+     *      if(details instanceof OAuth2AuthenticationDetails) {
+     *          Object decodedDetails = ((OAuth2AuthenticationDetails) details).getDecodedDetails();
+     *          if(decodedDetails != null &amp;&amp; decodedDetails instanceof Map) {
+     *             String detailFoo = ((Map) decodedDetails).get("foo");
+     *          }
+     *      }
+     *  }
+     * </code>
+     *  </pre>
+     * @param claims OAuth2JWTToken claims
+     * @return OAuth2Authentication
+     */
+    @Override
+    public OAuth2Authentication extractAuthentication(Map<String, ?> claims) {
+        OAuth2Authentication authentication = super.extractAuthentication(claims);
+        authentication.setDetails(claims);
+        return authentication;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/oauth2/OAuth2Properties.java

@@ -0,0 +1,118 @@
+package com.baeldung.jhipster.gateway.config.oauth2;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.stereotype.Component;
+
+/**
+ * OAuth2 properties define properties for OAuth2-based microservices.
+ */
+@Component
+@ConfigurationProperties(prefix = "oauth2", ignoreUnknownFields = false)
+public class OAuth2Properties {
+    private WebClientConfiguration webClientConfiguration = new WebClientConfiguration();
+
+    private SignatureVerification signatureVerification = new SignatureVerification();
+
+    public WebClientConfiguration getWebClientConfiguration() {
+        return webClientConfiguration;
+    }
+
+    public SignatureVerification getSignatureVerification() {
+        return signatureVerification;
+    }
+
+    public static class WebClientConfiguration {
+        private String clientId = "web_app";
+        private String secret = "changeit";
+        /**
+         * Holds the session timeout in seconds for non-remember-me sessions.
+         * After so many seconds of inactivity, the session will be terminated.
+         * Only checked during token refresh, so long access token validity may
+         * delay the session timeout accordingly.
+         */
+        private int sessionTimeoutInSeconds = 1800;
+        /**
+         * Defines the cookie domain. If specified, cookies will be set on this domain.
+         * If not configured, then cookies will be set on the top-level domain of the
+         * request you sent, i.e. if you send a request to <code>app1.your-domain.com</code>,
+         * then cookies will be set <code>on .your-domain.com</code>, such that they
+         * are also valid for <code>app2.your-domain.com</code>.
+         */
+        private String cookieDomain;
+
+        public String getClientId() {
+            return clientId;
+        }
+
+        public void setClientId(String clientId) {
+            this.clientId = clientId;
+        }
+
+        public String getSecret() {
+            return secret;
+        }
+
+        public void setSecret(String secret) {
+            this.secret = secret;
+        }
+
+        public int getSessionTimeoutInSeconds() {
+            return sessionTimeoutInSeconds;
+        }
+
+        public void setSessionTimeoutInSeconds(int sessionTimeoutInSeconds) {
+            this.sessionTimeoutInSeconds = sessionTimeoutInSeconds;
+        }
+
+        public String getCookieDomain() {
+            return cookieDomain;
+        }
+
+        public void setCookieDomain(String cookieDomain) {
+            this.cookieDomain = cookieDomain;
+        }
+    }
+
+    public static class SignatureVerification {
+        /**
+         * Maximum refresh rate for public keys in ms.
+         * We won't fetch new public keys any faster than that to avoid spamming UAA in case
+         * we receive a lot of "illegal" tokens.
+         */
+        private long publicKeyRefreshRateLimit = 10 * 1000L;
+        /**
+         * Maximum TTL for the public key in ms.
+         * The public key will be fetched again from UAA if it gets older than that.
+         * That way, we make sure that we get the newest keys always in case they are updated there.
+         */
+        private long ttl = 24 * 60 * 60 * 1000L;
+        /**
+         * Endpoint where to retrieve the public key used to verify token signatures.
+         */
+        private String publicKeyEndpointUri = "http://uaa/oauth/token_key";
+
+        public long getPublicKeyRefreshRateLimit() {
+            return publicKeyRefreshRateLimit;
+        }
+
+        public void setPublicKeyRefreshRateLimit(long publicKeyRefreshRateLimit) {
+            this.publicKeyRefreshRateLimit = publicKeyRefreshRateLimit;
+        }
+
+        public long getTtl() {
+            return ttl;
+        }
+
+        public void setTtl(long ttl) {
+            this.ttl = ttl;
+        }
+
+        public String getPublicKeyEndpointUri() {
+            return publicKeyEndpointUri;
+        }
+
+        public void setPublicKeyEndpointUri(String publicKeyEndpointUri) {
+            this.publicKeyEndpointUri = publicKeyEndpointUri;
+        }
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/config/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Spring Framework configuration files.
+ */
+package com.baeldung.jhipster.gateway.config;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/domain/AbstractAuditingEntity.java

@@ -0,0 +1,79 @@
+package com.baeldung.jhipster.gateway.domain;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import org.hibernate.envers.Audited;
+import org.springframework.data.annotation.CreatedBy;
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.annotation.LastModifiedBy;
+import org.springframework.data.annotation.LastModifiedDate;
+import org.springframework.data.jpa.domain.support.AuditingEntityListener;
+
+import java.io.Serializable;
+import java.time.Instant;
+import javax.persistence.Column;
+import javax.persistence.EntityListeners;
+import javax.persistence.MappedSuperclass;
+
+/**
+ * Base abstract class for entities which will hold definitions for created, last modified by and created,
+ * last modified by date.
+ */
+@MappedSuperclass
+@Audited
+@EntityListeners(AuditingEntityListener.class)
+public abstract class AbstractAuditingEntity implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @CreatedBy
+    @Column(name = "created_by", nullable = false, length = 50, updatable = false)
+    @JsonIgnore
+    private String createdBy;
+
+    @CreatedDate
+    @Column(name = "created_date", nullable = false, updatable = false)
+    @JsonIgnore
+    private Instant createdDate = Instant.now();
+
+    @LastModifiedBy
+    @Column(name = "last_modified_by", length = 50)
+    @JsonIgnore
+    private String lastModifiedBy;
+
+    @LastModifiedDate
+    @Column(name = "last_modified_date")
+    @JsonIgnore
+    private Instant lastModifiedDate = Instant.now();
+
+    public String getCreatedBy() {
+        return createdBy;
+    }
+
+    public void setCreatedBy(String createdBy) {
+        this.createdBy = createdBy;
+    }
+
+    public Instant getCreatedDate() {
+        return createdDate;
+    }
+
+    public void setCreatedDate(Instant createdDate) {
+        this.createdDate = createdDate;
+    }
+
+    public String getLastModifiedBy() {
+        return lastModifiedBy;
+    }
+
+    public void setLastModifiedBy(String lastModifiedBy) {
+        this.lastModifiedBy = lastModifiedBy;
+    }
+
+    public Instant getLastModifiedDate() {
+        return lastModifiedDate;
+    }
+
+    public void setLastModifiedDate(Instant lastModifiedDate) {
+        this.lastModifiedDate = lastModifiedDate;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/domain/PersistentAuditEvent.java

@@ -0,0 +1,81 @@
+package com.baeldung.jhipster.gateway.domain;
+
+import javax.persistence.*;
+import javax.validation.constraints.NotNull;
+import java.io.Serializable;
+import java.time.Instant;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Persist AuditEvent managed by the Spring Boot actuator.
+ *
+ * @see org.springframework.boot.actuate.audit.AuditEvent
+ */
+@Entity
+@Table(name = "jhi_persistent_audit_event")
+public class PersistentAuditEvent implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "event_id")
+    private Long id;
+
+    @NotNull
+    @Column(nullable = false)
+    private String principal;
+
+    @Column(name = "event_date")
+    private Instant auditEventDate;
+
+    @Column(name = "event_type")
+    private String auditEventType;
+
+    @ElementCollection
+    @MapKeyColumn(name = "name")
+    @Column(name = "value")
+    @CollectionTable(name = "jhi_persistent_audit_evt_data", joinColumns=@JoinColumn(name="event_id"))
+    private Map<String, String> data = new HashMap<>();
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getPrincipal() {
+        return principal;
+    }
+
+    public void setPrincipal(String principal) {
+        this.principal = principal;
+    }
+
+    public Instant getAuditEventDate() {
+        return auditEventDate;
+    }
+
+    public void setAuditEventDate(Instant auditEventDate) {
+        this.auditEventDate = auditEventDate;
+    }
+
+    public String getAuditEventType() {
+        return auditEventType;
+    }
+
+    public void setAuditEventType(String auditEventType) {
+        this.auditEventType = auditEventType;
+    }
+
+    public Map<String, String> getData() {
+        return data;
+    }
+
+    public void setData(Map<String, String> data) {
+        this.data = data;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/domain/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * JPA domain objects.
+ */
+package com.baeldung.jhipster.gateway.domain;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/gateway/accesscontrol/AccessControlFilter.java

@@ -0,0 +1,99 @@
+package com.baeldung.jhipster.gateway.gateway.accesscontrol;
+
+import io.github.jhipster.config.JHipsterProperties;
+
+import java.util.List;
+import java.util.Map;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.netflix.zuul.filters.Route;
+import org.springframework.cloud.netflix.zuul.filters.RouteLocator;
+import org.springframework.http.HttpStatus;
+
+import com.netflix.zuul.ZuulFilter;
+import com.netflix.zuul.context.RequestContext;
+
+/**
+ * Zuul filter for restricting access to backend micro-services endpoints.
+ */
+public class AccessControlFilter extends ZuulFilter {
+
+    private final Logger log = LoggerFactory.getLogger(AccessControlFilter.class);
+
+    private final RouteLocator routeLocator;
+
+    private final JHipsterProperties jHipsterProperties;
+
+    public AccessControlFilter(RouteLocator routeLocator, JHipsterProperties jHipsterProperties) {
+        this.routeLocator = routeLocator;
+        this.jHipsterProperties = jHipsterProperties;
+    }
+
+    @Override
+    public String filterType() {
+        return "pre";
+    }
+
+    @Override
+    public int filterOrder() {
+        return 0;
+    }
+
+    /**
+     * Filter requests on endpoints that are not in the list of authorized microservices endpoints.
+     */
+    @Override
+    public boolean shouldFilter() {
+        String requestUri = RequestContext.getCurrentContext().getRequest().getRequestURI();
+        String contextPath = RequestContext.getCurrentContext().getRequest().getContextPath();
+
+        // If the request Uri does not start with the path of the authorized endpoints, we block the request
+        for (Route route : routeLocator.getRoutes()) {
+            String serviceUrl = contextPath + route.getFullPath();
+            String serviceName = route.getId();
+
+            // If this route correspond to the current request URI
+            // We do a substring to remove the "**" at the end of the route URL
+            if (requestUri.startsWith(serviceUrl.substring(0, serviceUrl.length() - 2))) {
+				return !isAuthorizedRequest(serviceUrl, serviceName, requestUri);
+            }
+        }
+        return true;
+    }
+
+    private boolean isAuthorizedRequest(String serviceUrl, String serviceName, String requestUri) {
+        Map<String, List<String>> authorizedMicroservicesEndpoints = jHipsterProperties.getGateway()
+            .getAuthorizedMicroservicesEndpoints();
+
+        // If the authorized endpoints list was left empty for this route, all access are allowed
+        if (authorizedMicroservicesEndpoints.get(serviceName) == null) {
+            log.debug("Access Control: allowing access for {}, as no access control policy has been set up for " +
+                "service: {}", requestUri, serviceName);
+            return true;
+        } else {
+            List<String> authorizedEndpoints = authorizedMicroservicesEndpoints.get(serviceName);
+
+            // Go over the authorized endpoints to control that the request URI matches it
+            for (String endpoint : authorizedEndpoints) {
+                // We do a substring to remove the "**/" at the end of the route URL
+                String gatewayEndpoint = serviceUrl.substring(0, serviceUrl.length() - 3) + endpoint;
+                if (requestUri.startsWith(gatewayEndpoint)) {
+                    log.debug("Access Control: allowing access for {}, as it matches the following authorized " +
+                        "microservice endpoint: {}", requestUri, gatewayEndpoint);
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public Object run() {
+        RequestContext ctx = RequestContext.getCurrentContext();
+        ctx.setResponseStatusCode(HttpStatus.FORBIDDEN.value());
+        ctx.setSendZuulResponse(false);
+        log.debug("Access Control: filtered unauthorized access on endpoint {}", ctx.getRequest().getRequestURI());
+        return null;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/gateway/ratelimiting/RateLimitingFilter.java

@@ -0,0 +1,121 @@
+package com.baeldung.jhipster.gateway.gateway.ratelimiting;
+
+import com.baeldung.jhipster.gateway.security.SecurityUtils;
+
+import java.time.Duration;
+import java.util.function.Supplier;
+import javax.cache.CacheManager;
+import javax.cache.Caching;
+import javax.cache.configuration.CompleteConfiguration;
+import javax.cache.configuration.MutableConfiguration;
+import javax.cache.spi.CachingProvider;
+import javax.servlet.http.HttpServletRequest;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+
+import com.netflix.zuul.ZuulFilter;
+import com.netflix.zuul.context.RequestContext;
+
+import io.github.bucket4j.*;
+import io.github.bucket4j.grid.GridBucketState;
+import io.github.bucket4j.grid.ProxyManager;
+import io.github.bucket4j.grid.jcache.JCache;
+import io.github.jhipster.config.JHipsterProperties;
+
+/**
+ * Zuul filter for limiting the number of HTTP calls per client.
+ *
+ * See the Bucket4j documentation at https://github.com/vladimir-bukhtoyarov/bucket4j
+ * https://github.com/vladimir-bukhtoyarov/bucket4j/blob/master/doc-pages/jcache-usage
+ * .md#example-1---limiting-access-to-http-server-by-ip-address
+ */
+public class RateLimitingFilter extends ZuulFilter {
+
+    private final Logger log = LoggerFactory.getLogger(RateLimitingFilter.class);
+
+    public final static String GATEWAY_RATE_LIMITING_CACHE_NAME = "gateway-rate-limiting";
+
+    private final JHipsterProperties jHipsterProperties;
+
+    private javax.cache.Cache<String, GridBucketState> cache;
+
+    private ProxyManager<String> buckets;
+
+    public RateLimitingFilter(JHipsterProperties jHipsterProperties) {
+        this.jHipsterProperties = jHipsterProperties;
+
+        CachingProvider cachingProvider = Caching.getCachingProvider();
+        CacheManager cacheManager = cachingProvider.getCacheManager();
+        CompleteConfiguration<String, GridBucketState> config =
+            new MutableConfiguration<String, GridBucketState>()
+                .setTypes(String.class, GridBucketState.class);
+
+        this.cache = cacheManager.createCache(GATEWAY_RATE_LIMITING_CACHE_NAME, config);
+        this.buckets = Bucket4j.extension(JCache.class).proxyManagerForCache(cache);
+    }
+
+    @Override
+    public String filterType() {
+        return "pre";
+    }
+
+    @Override
+    public int filterOrder() {
+        return 10;
+    }
+
+    @Override
+    public boolean shouldFilter() {
+        // specific APIs can be filtered out using
+        // if (RequestContext.getCurrentContext().getRequest().getRequestURI().startsWith("/api")) { ... }
+        return true;
+    }
+
+    @Override
+    public Object run() {
+        String bucketId = getId(RequestContext.getCurrentContext().getRequest());
+        Bucket bucket = buckets.getProxy(bucketId, getConfigSupplier());
+        if (bucket.tryConsume(1)) {
+            // the limit is not exceeded
+            log.debug("API rate limit OK for {}", bucketId);
+        } else {
+            // limit is exceeded
+            log.info("API rate limit exceeded for {}", bucketId);
+            apiLimitExceeded();
+        }
+        return null;
+    }
+
+    private Supplier<BucketConfiguration> getConfigSupplier() {
+        return () -> {
+            JHipsterProperties.Gateway.RateLimiting rateLimitingProperties =
+                jHipsterProperties.getGateway().getRateLimiting();
+
+            return Bucket4j.configurationBuilder()
+                .addLimit(Bandwidth.simple(rateLimitingProperties.getLimit(),
+                    Duration.ofSeconds(rateLimitingProperties.getDurationInSeconds())))
+                .build();
+        };
+    }
+
+    /**
+     * Create a Zuul response error when the API limit is exceeded.
+     */
+    private void apiLimitExceeded() {
+        RequestContext ctx = RequestContext.getCurrentContext();
+        ctx.setResponseStatusCode(HttpStatus.TOO_MANY_REQUESTS.value());
+        if (ctx.getResponseBody() == null) {
+            ctx.setResponseBody("API rate limit exceeded");
+            ctx.setSendZuulResponse(false);
+        }
+    }
+
+    /**
+     * The ID that will identify the limit: the user login or the user IP address.
+     */
+    private String getId(HttpServletRequest httpServletRequest) {
+        return SecurityUtils.getCurrentUserLogin().orElse(httpServletRequest.getRemoteAddr());
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/gateway/responserewriting/SwaggerBasePathRewritingFilter.java

@@ -0,0 +1,99 @@
+package com.baeldung.jhipster.gateway.gateway.responserewriting;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.netflix.zuul.context.RequestContext;
+import org.apache.commons.io.IOUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
+import org.springframework.cloud.netflix.zuul.filters.post.SendResponseFilter;
+import springfox.documentation.swagger2.web.Swagger2Controller;
+
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import java.util.LinkedHashMap;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
+
+/**
+ * Zuul filter to rewrite micro-services Swagger URL Base Path.
+ */
+public class SwaggerBasePathRewritingFilter extends SendResponseFilter {
+
+    private final Logger log = LoggerFactory.getLogger(SwaggerBasePathRewritingFilter.class);
+
+    private ObjectMapper mapper = new ObjectMapper();
+
+    public SwaggerBasePathRewritingFilter() {
+        super(new ZuulProperties());
+    }
+
+    @Override
+    public String filterType() {
+        return "post";
+    }
+
+    @Override
+    public int filterOrder() {
+        return 100;
+    }
+
+    /**
+     * Filter requests to micro-services Swagger docs.
+     */
+    @Override
+    public boolean shouldFilter() {
+        return RequestContext.getCurrentContext().getRequest().getRequestURI().endsWith(Swagger2Controller.DEFAULT_URL);
+    }
+
+    @Override
+    public Object run() {
+        RequestContext context = RequestContext.getCurrentContext();
+
+        context.getResponse().setCharacterEncoding("UTF-8");
+
+        String rewrittenResponse = rewriteBasePath(context);
+        if (context.getResponseGZipped()) {
+            try {
+                context.setResponseDataStream(new ByteArrayInputStream(gzipData(rewrittenResponse)));
+            } catch (IOException e) {
+                log.error("Swagger-docs filter error", e);
+            }
+        } else {
+            context.setResponseBody(rewrittenResponse);
+        }
+        return null;
+    }
+
+    @SuppressWarnings("unchecked")
+    private String rewriteBasePath(RequestContext context) {
+        InputStream responseDataStream = context.getResponseDataStream();
+        String requestUri = RequestContext.getCurrentContext().getRequest().getRequestURI();
+        try {
+            if (context.getResponseGZipped()) {
+                responseDataStream = new GZIPInputStream(context.getResponseDataStream());
+            }
+            String response = IOUtils.toString(responseDataStream, StandardCharsets.UTF_8);
+            if (response != null) {
+                LinkedHashMap<String, Object> map = this.mapper.readValue(response, LinkedHashMap.class);
+
+                String basePath = requestUri.replace(Swagger2Controller.DEFAULT_URL, "");
+                map.put("basePath", basePath);
+                log.debug("Swagger-docs: rewritten Base URL with correct micro-service route: {}", basePath);
+                return mapper.writeValueAsString(map);
+            }
+        } catch (IOException e) {
+            log.error("Swagger-docs filter error", e);
+        }
+        return null;
+    }
+
+    public static byte[] gzipData(String content) throws IOException {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        PrintWriter gzip = new PrintWriter(new GZIPOutputStream(bos));
+        gzip.print(content);
+        gzip.flush();
+        gzip.close();
+        return bos.toByteArray();
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/repository/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Spring Data JPA repositories.
+ */
+package com.baeldung.jhipster.gateway.repository;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/AuthoritiesConstants.java

@@ -0,0 +1,16 @@
+package com.baeldung.jhipster.gateway.security;
+
+/**
+ * Constants for Spring Security authorities.
+ */
+public final class AuthoritiesConstants {
+
+    public static final String ADMIN = "ROLE_ADMIN";
+
+    public static final String USER = "ROLE_USER";
+
+    public static final String ANONYMOUS = "ROLE_ANONYMOUS";
+
+    private AuthoritiesConstants() {
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/SecurityUtils.java

@@ -0,0 +1,64 @@
+package com.baeldung.jhipster.gateway.security;
+
+import org.springframework.security.core.context.SecurityContext;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.core.userdetails.UserDetails;
+
+import java.util.Optional;
+
+/**
+ * Utility class for Spring Security.
+ */
+public final class SecurityUtils {
+
+    private SecurityUtils() {
+    }
+
+    /**
+     * Get the login of the current user.
+     *
+     * @return the login of the current user
+     */
+    public static Optional<String> getCurrentUserLogin() {
+        SecurityContext securityContext = SecurityContextHolder.getContext();
+        return Optional.ofNullable(securityContext.getAuthentication())
+            .map(authentication -> {
+                if (authentication.getPrincipal() instanceof UserDetails) {
+                    UserDetails springSecurityUser = (UserDetails) authentication.getPrincipal();
+                    return springSecurityUser.getUsername();
+                } else if (authentication.getPrincipal() instanceof String) {
+                    return (String) authentication.getPrincipal();
+                }
+                return null;
+            });
+    }
+
+    /**
+     * Check if a user is authenticated.
+     *
+     * @return true if the user is authenticated, false otherwise
+     */
+    public static boolean isAuthenticated() {
+        SecurityContext securityContext = SecurityContextHolder.getContext();
+        return Optional.ofNullable(securityContext.getAuthentication())
+            .map(authentication -> authentication.getAuthorities().stream()
+                .noneMatch(grantedAuthority -> grantedAuthority.getAuthority().equals(AuthoritiesConstants.ANONYMOUS)))
+            .orElse(false);
+    }
+
+    /**
+     * If the current user has a specific authority (security role).
+     * <p>
+     * The name of this method comes from the isUserInRole() method in the Servlet API
+     *
+     * @param authority the authority to check
+     * @return true if the current user has the authority, false otherwise
+     */
+    public static boolean isCurrentUserInRole(String authority) {
+        SecurityContext securityContext = SecurityContextHolder.getContext();
+        return Optional.ofNullable(securityContext.getAuthentication())
+            .map(authentication -> authentication.getAuthorities().stream()
+                .anyMatch(grantedAuthority -> grantedAuthority.getAuthority().equals(authority)))
+            .orElse(false);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/SpringSecurityAuditorAware.java

@@ -0,0 +1,20 @@
+package com.baeldung.jhipster.gateway.security;
+
+import com.baeldung.jhipster.gateway.config.Constants;
+
+import java.util.Optional;
+
+import org.springframework.data.domain.AuditorAware;
+import org.springframework.stereotype.Component;
+
+/**
+ * Implementation of AuditorAware based on Spring Security.
+ */
+@Component
+public class SpringSecurityAuditorAware implements AuditorAware<String> {
+
+    @Override
+    public Optional<String> getCurrentAuditor() {
+        return Optional.of(SecurityUtils.getCurrentUserLogin().orElse(Constants.SYSTEM_ACCOUNT));
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/CookieCollection.java

@@ -0,0 +1,139 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import javax.servlet.http.Cookie;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+/**
+ * A Collection of Cookies that allows modification - unlike a mere array.
+ * <p>
+ * Since {@link Cookie} doesn't implement <code>hashCode</code> nor <code>equals</code>,
+ * we cannot simply put it into a <code>HashSet</code>.
+ */
+public class CookieCollection implements Collection<Cookie> {
+    private final Map<String, Cookie> cookieMap;
+
+    public CookieCollection() {
+        cookieMap = new HashMap<>();
+    }
+
+    public CookieCollection(Cookie... cookies) {
+        this(Arrays.asList(cookies));
+    }
+
+    public CookieCollection(Collection<? extends Cookie> cookies) {
+        cookieMap = new HashMap<>(cookies.size());
+        addAll(cookies);
+    }
+
+    @Override
+    public int size() {
+        return cookieMap.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return cookieMap.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        if (o instanceof String) {
+            return cookieMap.containsKey(o);
+        }
+        if (o instanceof Cookie) {
+            return cookieMap.containsValue(o);
+        }
+        return false;
+    }
+
+    @Override
+    public Iterator<Cookie> iterator() {
+        return cookieMap.values().iterator();
+    }
+
+    public Cookie[] toArray() {
+        Cookie[] cookies = new Cookie[cookieMap.size()];
+        return toArray(cookies);
+    }
+
+    @Override
+    public <T> T[] toArray(T[] ts) {
+        return cookieMap.values().toArray(ts);
+    }
+
+    @Override
+    public boolean add(Cookie cookie) {
+        if (cookie == null) {
+            return false;
+        }
+        cookieMap.put(cookie.getName(), cookie);
+        return true;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        if (o instanceof String) {
+            return cookieMap.remove((String)o) != null;
+        }
+        if (o instanceof Cookie) {
+            Cookie c = (Cookie)o;
+            return cookieMap.remove(c.getName()) != null;
+        }
+        return false;
+    }
+
+    public Cookie get(String name) {
+        return cookieMap.get(name);
+    }
+
+    @Override
+    public boolean containsAll(Collection<?> collection) {
+        for(Object o : collection) {
+            if (!contains(o)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends Cookie> collection) {
+        boolean result = false;
+        for(Cookie cookie : collection) {
+            result|= add(cookie);
+        }
+        return result;
+    }
+
+    @Override
+    public boolean removeAll(Collection<?> collection) {
+        boolean result = false;
+        for(Object cookie : collection) {
+            result|= remove(cookie);
+        }
+        return result;
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> collection) {
+        boolean result = false;
+        Iterator<Map.Entry<String, Cookie>> it = cookieMap.entrySet().iterator();
+        while(it.hasNext()) {
+            Map.Entry<String, Cookie> e = it.next();
+            if (!collection.contains(e.getKey()) && !collection.contains(e.getValue())) {
+                it.remove();
+                result = true;
+            }
+        }
+        return result;
+    }
+
+    @Override
+    public void clear() {
+        cookieMap.clear();
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/CookieTokenExtractor.java

@@ -0,0 +1,33 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import org.springframework.security.oauth2.provider.authentication.BearerTokenExtractor;
+
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletRequest;
+
+/**
+ * Extracts the access token from a cookie.
+ * Falls back to a <code>BearerTokenExtractor</code> extracting information from the Authorization header, if no
+ * cookie was found.
+ */
+public class CookieTokenExtractor extends BearerTokenExtractor {
+    /**
+     * Extract the JWT access token from the request, if present.
+     * If not, then it falls back to the {@link BearerTokenExtractor} behaviour.
+     *
+     * @param request the request containing the cookies.
+     * @return the extracted JWT token; or null.
+     */
+    @Override
+    protected String extractToken(HttpServletRequest request) {
+        String result;
+        Cookie accessTokenCookie = OAuth2CookieHelper.getAccessTokenCookie(request);
+        if (accessTokenCookie != null) {
+            result = accessTokenCookie.getValue();
+        } else {
+            result = super.extractToken(request);
+        }
+        return result;
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/CookiesHttpServletRequestWrapper.java

@@ -0,0 +1,31 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletRequestWrapper;
+
+/**
+ * A request mapper used to modify the cookies in the original request.
+ * This is needed such that we can modify the cookies of the request during a token refresh.
+ * The token refresh happens before authentication by the <code>OAuth2AuthenticationProcessingFilter</code>
+ * so we must make sure that further in the filter chain, we have the new cookies and not the expired/missing ones.
+ */
+class CookiesHttpServletRequestWrapper extends HttpServletRequestWrapper {
+    /**
+     * The new cookies of the request. Use these instead of the ones found in the wrapped request.
+     */
+    private Cookie[] cookies;
+
+    public CookiesHttpServletRequestWrapper(HttpServletRequest request, Cookie[] cookies) {
+        super(request);
+        this.cookies = cookies;
+    }
+
+    /**
+     * Return the modified cookies instead of the original ones.
+     */
+    @Override
+    public Cookie[] getCookies() {
+        return cookies;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/OAuth2AuthenticationService.java

@@ -0,0 +1,163 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import com.baeldung.jhipster.gateway.web.rest.errors.InvalidPasswordException;
+import io.github.jhipster.security.PersistentTokenCache;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+import org.springframework.web.client.HttpClientErrorException;
+
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.util.Map;
+
+/**
+ * Manages authentication cases for OAuth2 updating the cookies holding access and refresh tokens accordingly.
+ * <p>
+ * It can authenticate users, refresh the token cookies should they expire and log users out.
+ */
+public class OAuth2AuthenticationService {
+
+    private final Logger log = LoggerFactory.getLogger(OAuth2AuthenticationService.class);
+
+    /**
+     * Number of milliseconds to cache refresh token grants so we don't have to repeat them in case of parallel requests.
+     */
+    private static final long REFRESH_TOKEN_VALIDITY_MILLIS = 10000l;
+
+    /**
+     * Used to contact the OAuth2 token endpoint.
+     */
+    private final OAuth2TokenEndpointClient authorizationClient;
+
+    /**
+     * Helps us with cookie handling.
+     */
+    private final OAuth2CookieHelper cookieHelper;
+
+    /**
+     * Caches Refresh grant results for a refresh token value so we can reuse them.
+     * This avoids hammering UAA in case of several multi-threaded requests arriving in parallel.
+     */
+    private final PersistentTokenCache<OAuth2Cookies> recentlyRefreshed;
+
+    public OAuth2AuthenticationService(OAuth2TokenEndpointClient authorizationClient, OAuth2CookieHelper cookieHelper) {
+        this.authorizationClient = authorizationClient;
+        this.cookieHelper = cookieHelper;
+        recentlyRefreshed = new PersistentTokenCache<>(REFRESH_TOKEN_VALIDITY_MILLIS);
+    }
+
+    /**
+     * Authenticate the user by username and password.
+     *
+     * @param request  the request coming from the client.
+     * @param response the response going back to the server.
+     * @param params   the params holding the username, password and rememberMe.
+     * @return the OAuth2AccessToken as a ResponseEntity. Will return OK (200), if successful.
+     * If the UAA cannot authenticate the user, the status code returned by UAA will be returned.
+     */
+    public ResponseEntity<OAuth2AccessToken> authenticate(HttpServletRequest request, HttpServletResponse response,
+                                                          Map<String, String> params) {
+        try {
+            String username = params.get("username");
+            String password = params.get("password");
+            boolean rememberMe = Boolean.valueOf(params.get("rememberMe"));
+            OAuth2AccessToken accessToken = authorizationClient.sendPasswordGrant(username, password);
+            OAuth2Cookies cookies = new OAuth2Cookies();
+            cookieHelper.createCookies(request, accessToken, rememberMe, cookies);
+            cookies.addCookiesTo(response);
+            if (log.isDebugEnabled()) {
+                log.debug("successfully authenticated user {}", params.get("username"));
+            }
+            return ResponseEntity.ok(accessToken);
+        } catch (HttpClientErrorException ex) {
+            log.error("failed to get OAuth2 tokens from UAA", ex);
+            throw new InvalidPasswordException();
+        }
+    }
+
+    /**
+     * Try to refresh the access token using the refresh token provided as cookie.
+     * Note that browsers typically send multiple requests in parallel which means the access token
+     * will be expired on multiple threads. We don't want to send multiple requests to UAA though,
+     * so we need to cache results for a certain duration and synchronize threads to avoid sending
+     * multiple requests in parallel.
+     *
+     * @param request       the request potentially holding the refresh token.
+     * @param response      the response setting the new cookies (if refresh was successful).
+     * @param refreshCookie the refresh token cookie. Must not be null.
+     * @return the new servlet request containing the updated cookies for relaying downstream.
+     */
+    public HttpServletRequest refreshToken(HttpServletRequest request, HttpServletResponse response, Cookie
+        refreshCookie) {
+        //check if non-remember-me session has expired
+        if (cookieHelper.isSessionExpired(refreshCookie)) {
+            log.info("session has expired due to inactivity");
+            logout(request, response);       //logout to clear cookies in browser
+            return stripTokens(request);            //don't include cookies downstream
+        }
+        OAuth2Cookies cookies = getCachedCookies(refreshCookie.getValue());
+        synchronized (cookies) {
+            //check if we have a result from another thread already
+            if (cookies.getAccessTokenCookie() == null) {            //no, we are first!
+                //send a refresh_token grant to UAA, getting new tokens
+                String refreshCookieValue = OAuth2CookieHelper.getRefreshTokenValue(refreshCookie);
+                OAuth2AccessToken accessToken = authorizationClient.sendRefreshGrant(refreshCookieValue);
+                boolean rememberMe = OAuth2CookieHelper.isRememberMe(refreshCookie);
+                cookieHelper.createCookies(request, accessToken, rememberMe, cookies);
+                //add cookies to response to update browser
+                cookies.addCookiesTo(response);
+            } else {
+                log.debug("reusing cached refresh_token grant");
+            }
+            //replace cookies in original request with new ones
+            CookieCollection requestCookies = new CookieCollection(request.getCookies());
+            requestCookies.add(cookies.getAccessTokenCookie());
+            requestCookies.add(cookies.getRefreshTokenCookie());
+            return new CookiesHttpServletRequestWrapper(request, requestCookies.toArray());
+        }
+    }
+
+    /**
+     * Get the result from the cache in a thread-safe manner.
+     *
+     * @param refreshTokenValue the refresh token for which we want the results.
+     * @return a RefreshGrantResult for that token. This will either be empty, if we are the first one to do the
+     * request,
+     * or contain some results already, if another thread already handled the grant for us.
+     */
+    private OAuth2Cookies getCachedCookies(String refreshTokenValue) {
+        synchronized (recentlyRefreshed) {
+            OAuth2Cookies ctx = recentlyRefreshed.get(refreshTokenValue);
+            if (ctx == null) {
+                ctx = new OAuth2Cookies();
+                recentlyRefreshed.put(refreshTokenValue, ctx);
+            }
+            return ctx;
+        }
+    }
+
+    /**
+     * Logs the user out by clearing all cookies.
+     *
+     * @param httpServletRequest  the request containing the Cookies.
+     * @param httpServletResponse the response used to clear them.
+     */
+    public void logout(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) {
+        cookieHelper.clearCookies(httpServletRequest, httpServletResponse);
+    }
+
+    /**
+     * Strips token cookies preventing them from being used further down the chain.
+     * For example, the OAuth2 client won't checked them and they won't be relayed to other services.
+     *
+     * @param httpServletRequest the incoming request.
+     * @return the request to replace it with which has the tokens stripped.
+     */
+    public HttpServletRequest stripTokens(HttpServletRequest httpServletRequest) {
+        Cookie[] cookies = cookieHelper.stripCookies(httpServletRequest.getCookies());
+        return new CookiesHttpServletRequestWrapper(httpServletRequest, cookies);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/OAuth2CookieHelper.java

@@ -0,0 +1,334 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import com.baeldung.jhipster.gateway.config.oauth2.OAuth2Properties;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.json.JsonParser;
+import org.springframework.boot.json.JsonParserFactory;
+import org.springframework.security.jwt.Jwt;
+import org.springframework.security.jwt.JwtHelper;
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+import org.springframework.security.oauth2.common.OAuth2RefreshToken;
+import org.springframework.security.oauth2.common.exceptions.InvalidTokenException;
+import org.springframework.security.oauth2.provider.token.AccessTokenConverter;
+import org.springframework.util.StringUtils;
+
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+import static org.apache.http.conn.util.InetAddressUtils.isIPv4Address;
+import static org.apache.http.conn.util.InetAddressUtils.isIPv6Address;
+import org.apache.http.conn.util.PublicSuffixMatcher;
+import org.apache.http.conn.util.PublicSuffixMatcherLoader;
+
+/**
+ * Helps with OAuth2 cookie handling.
+ */
+public class OAuth2CookieHelper {
+    /**
+     * Name of the access token cookie.
+     */
+    public static final String ACCESS_TOKEN_COOKIE = OAuth2AccessToken.ACCESS_TOKEN;
+    /**
+     * Name of the refresh token cookie in case of remember me.
+     */
+    public static final String REFRESH_TOKEN_COOKIE = OAuth2AccessToken.REFRESH_TOKEN;
+    /**
+     * Name of the session-only refresh token in case the user did not check remember me.
+     */
+    public static final String SESSION_TOKEN_COOKIE = "session_token";
+    /**
+     * The names of the Cookies we set.
+     */
+    private static final List<String> COOKIE_NAMES = Arrays.asList(ACCESS_TOKEN_COOKIE, REFRESH_TOKEN_COOKIE,
+        SESSION_TOKEN_COOKIE);
+    /**
+     * Number of seconds to expire refresh token cookies before the enclosed token expires.
+     * This makes sure we don't run into race conditions where the cookie is still there but
+     * expires while we process it.
+     */
+    private static final long REFRESH_TOKEN_EXPIRATION_WINDOW_SECS = 3L;
+
+    /**
+     * Public suffix matcher (to strip private subdomains off cookie scope).
+     */
+    PublicSuffixMatcher suffixMatcher;
+
+    private final Logger log = LoggerFactory.getLogger(OAuth2CookieHelper.class);
+
+    private OAuth2Properties oAuth2Properties;
+
+    /**
+     * Used to parse JWT claims.
+     */
+    private JsonParser jsonParser = JsonParserFactory.getJsonParser();
+
+    public OAuth2CookieHelper(OAuth2Properties oAuth2Properties) {
+        this.oAuth2Properties = oAuth2Properties;
+
+        // Alternatively, always get an up-to-date list by passing an URL
+        this.suffixMatcher = PublicSuffixMatcherLoader.getDefault();
+    }
+
+    public static Cookie getAccessTokenCookie(HttpServletRequest request) {
+        return getCookie(request, ACCESS_TOKEN_COOKIE);
+    }
+
+    public static Cookie getRefreshTokenCookie(HttpServletRequest request) {
+        Cookie cookie = getCookie(request, REFRESH_TOKEN_COOKIE);
+        if (cookie == null) {
+            cookie = getCookie(request, SESSION_TOKEN_COOKIE);
+        }
+        return cookie;
+    }
+
+
+    /**
+     * Get a cookie by name from the given servlet request.
+     *
+     * @param request    the request containing the cookie.
+     * @param cookieName the case-sensitive name of the cookie to get.
+     * @return the resulting Cookie; or null, if not found.
+     */
+    private static Cookie getCookie(HttpServletRequest request, String cookieName) {
+        if (request.getCookies() != null) {
+            for (Cookie cookie : request.getCookies()) {
+                if (cookie.getName().equals(cookieName)) {
+                    String value = cookie.getValue();
+                    if (StringUtils.hasText(value)) {
+                        return cookie;
+                    }
+                }
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Create cookies using the provided values.
+     *
+     * @param request     the request we are handling.
+     * @param accessToken the access token and enclosed refresh token for our cookies.
+     * @param rememberMe  whether the user had originally checked "remember me".
+     * @param result      will get the resulting cookies set.
+     */
+    public void createCookies(HttpServletRequest request, OAuth2AccessToken accessToken, boolean rememberMe,
+                              OAuth2Cookies result) {
+        String domain = getCookieDomain(request);
+        log.debug("creating cookies for domain {}", domain);
+        Cookie accessTokenCookie = new Cookie(ACCESS_TOKEN_COOKIE, accessToken.getValue());
+        setCookieProperties(accessTokenCookie, request.isSecure(), domain);
+        log.debug("created access token cookie '{}'", accessTokenCookie.getName());
+
+        OAuth2RefreshToken refreshToken = accessToken.getRefreshToken();
+        Cookie refreshTokenCookie = createRefreshTokenCookie(refreshToken, rememberMe);
+        setCookieProperties(refreshTokenCookie, request.isSecure(), domain);
+        log.debug("created refresh token cookie '{}', age: {}", refreshTokenCookie.getName(), refreshTokenCookie
+            .getMaxAge());
+
+        result.setCookies(accessTokenCookie, refreshTokenCookie);
+    }
+
+    /**
+     * Create a cookie out of the given refresh token.
+     * Refresh token cookies contain the base64 encoded refresh token (a JWT token).
+     * They also contain a hint whether the refresh token was for remember me or not.
+     * If not, then the cookie will be prefixed by the timestamp it was created at followed by a pipe '|'.
+     * This gives us the chance to expire session cookies regardless of the token duration.
+     */
+    private Cookie createRefreshTokenCookie(OAuth2RefreshToken refreshToken, boolean rememberMe) {
+        int maxAge = -1;
+        String name = SESSION_TOKEN_COOKIE;
+        String value = refreshToken.getValue();
+        if (rememberMe) {
+            name = REFRESH_TOKEN_COOKIE;
+            //get expiration in seconds from the token's "exp" claim
+            Integer exp = getClaim(refreshToken.getValue(), AccessTokenConverter.EXP, Integer.class);
+            if (exp != null) {
+                int now = (int) (System.currentTimeMillis() / 1000L);
+                maxAge = exp - now;
+                log.debug("refresh token valid for another {} secs", maxAge);
+                //let cookie expire a bit earlier than the token to avoid race conditions
+                maxAge -= REFRESH_TOKEN_EXPIRATION_WINDOW_SECS;
+            }
+        }
+        Cookie refreshTokenCookie = new Cookie(name, value);
+        refreshTokenCookie.setMaxAge(maxAge);
+        return refreshTokenCookie;
+    }
+
+    /**
+     * Returns true if the refresh token cookie was set with remember me checked.
+     * We can recognize this by the name of the cookie.
+     *
+     * @param refreshTokenCookie the cookie holding the refresh token.
+     * @return true, if it was set persistently (i.e. for "remember me").
+     */
+    public static boolean isRememberMe(Cookie refreshTokenCookie) {
+        return refreshTokenCookie.getName().equals(REFRESH_TOKEN_COOKIE);
+    }
+
+    /**
+     * Extracts the refresh token from the refresh token cookie.
+     * Since we encode additional information into the cookie, this needs to be called to get
+     * hold of the enclosed JWT.
+     *
+     * @param refreshCookie the cookie we store the value in.
+     * @return the refresh JWT from the cookie.
+     */
+    public static String getRefreshTokenValue(Cookie refreshCookie) {
+        String value = refreshCookie.getValue();
+        int i = value.indexOf('|');
+        if (i > 0) {
+            return value.substring(i + 1);
+        }
+        return value;
+    }
+
+    /**
+     * Checks if the refresh token session has expired.
+     * Only makes sense for non-persistent cookies, i.e. when remember me was not checked.
+     * The motivation for this is that we want to throw out a user after a while if he's inactive.
+     * We cannot do this via refresh token validity because that one is also used for remember me.
+     *
+     * @param refreshCookie the refresh token cookie to check.
+     * @return true, if the session is expired.
+     */
+    public boolean isSessionExpired(Cookie refreshCookie) {
+        if (isRememberMe(refreshCookie)) {       //no session expiration for "remember me"
+            return false;
+        }
+        //read non-remember-me session length in secs
+        int validity = oAuth2Properties.getWebClientConfiguration().getSessionTimeoutInSeconds();
+        if (validity < 0) {           //no session expiration configured
+            return false;
+        }
+        Integer iat = getClaim(refreshCookie.getValue(), "iat", Integer.class);
+        if (iat == null) {           //token creating timestamp in secs is missing, session does not expire
+            return false;
+        }
+        int now = (int) (System.currentTimeMillis() / 1000L);
+        int sessionDuration = now - iat;
+        log.debug("session duration {} secs, will timeout at {}", sessionDuration, validity);
+        return sessionDuration > validity;            //session has expired
+    }
+
+    /**
+     * Retrieve the given claim from the given token.
+     *
+     * @param refreshToken the JWT token to examine.
+     * @param claimName    name of the claim to get.
+     * @param clazz        the Class we expect to find there.
+     * @return the desired claim.
+     * @throws InvalidTokenException if we cannot find the claim in the token or it is of wrong type.
+     */
+    @SuppressWarnings("unchecked")
+    private <T> T getClaim(String refreshToken, String claimName, Class<T> clazz) {
+        Jwt jwt = JwtHelper.decode(refreshToken);
+        String claims = jwt.getClaims();
+        Map<String, Object> claimsMap = jsonParser.parseMap(claims);
+        Object claimValue = claimsMap.get(claimName);
+        if (claimValue == null) {
+            return null;
+        }
+        if (!clazz.isAssignableFrom(claimValue.getClass())) {
+            throw new InvalidTokenException("claim is not of expected type: " + claimName);
+        }
+        return (T) claimValue;
+    }
+
+    /**
+     * Set cookie properties of access and refresh tokens.
+     *
+     * @param cookie   the cookie to modify.
+     * @param isSecure whether it is coming from a secure request.
+     * @param domain   the domain for which the cookie is valid. If null, then will fall back to default.
+     */
+    private void setCookieProperties(Cookie cookie, boolean isSecure, String domain) {
+        cookie.setHttpOnly(true);
+        cookie.setPath("/");
+        cookie.setSecure(isSecure);       //if the request comes per HTTPS set the secure option on the cookie
+        if (domain != null) {
+            cookie.setDomain(domain);
+        }
+    }
+
+    /**
+     * Logs the user out by clearing all cookies.
+     *
+     * @param httpServletRequest  the request containing the Cookies.
+     * @param httpServletResponse the response used to clear them.
+     */
+    public void clearCookies(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) {
+        String domain = getCookieDomain(httpServletRequest);
+        for (String cookieName : COOKIE_NAMES) {
+            clearCookie(httpServletRequest, httpServletResponse, domain, cookieName);
+        }
+    }
+
+    private void clearCookie(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse,
+                             String domain, String cookieName) {
+        Cookie cookie = new Cookie(cookieName, "");
+        setCookieProperties(cookie, httpServletRequest.isSecure(), domain);
+        cookie.setMaxAge(0);
+        httpServletResponse.addCookie(cookie);
+        log.debug("clearing cookie {}", cookie.getName());
+    }
+
+    /**
+     * Returns the top level domain of the server from the request. This is used to limit the Cookie
+     * to the top domain instead of the full domain name.
+     * <p>
+     * A lot of times, individual gateways of the same domain get their own subdomain but authentication
+     * shall work across all subdomains of the top level domain.
+     * <p>
+     * For example, when sending a request to <code>app1.domain.com</code>,
+     * this returns <code>.domain.com</code>.
+     *
+     * @param request the HTTP request we received from the client.
+     * @return the top level domain to set the cookies for.
+     * Returns null if the domain is not under a public suffix (.com, .co.uk), e.g. for localhost.
+     */
+    private String getCookieDomain(HttpServletRequest request) {
+        String domain = oAuth2Properties.getWebClientConfiguration().getCookieDomain();
+        if (domain != null) {
+            return domain;
+        }
+        // if not explicitly defined, use top-level domain
+        domain = request.getServerName().toLowerCase();
+        // strip off leading www.
+        if (domain.startsWith("www.")) {
+            domain = domain.substring(4);
+        }
+        // if it isn't an IP address
+        if (!isIPv4Address(domain) && !isIPv6Address(domain)) {
+            // strip off private subdomains, leaving public TLD only
+            String suffix = suffixMatcher.getDomainRoot(domain);
+            if (suffix != null && !suffix.equals(domain)) {
+                // preserve leading dot
+                return "." + suffix;
+            }
+        }
+        // no top-level domain, stick with default domain
+        return null;
+    }
+
+    /**
+     * Strip our token cookies from the array.
+     *
+     * @param cookies the cookies we receive as input.
+     * @return the new cookie array without our tokens.
+     */
+    Cookie[] stripCookies(Cookie[] cookies) {
+        CookieCollection cc = new CookieCollection(cookies);
+        if (cc.removeAll(COOKIE_NAMES)) {
+            return cc.toArray();
+        }
+        return cookies;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/OAuth2Cookies.java

@@ -0,0 +1,35 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletResponse;
+
+/**
+ * Holds the access token and refresh token cookies.
+ */
+class OAuth2Cookies {
+    private Cookie accessTokenCookie;
+    private Cookie refreshTokenCookie;
+
+    public Cookie getAccessTokenCookie() {
+        return accessTokenCookie;
+    }
+
+    public Cookie getRefreshTokenCookie() {
+        return refreshTokenCookie;
+    }
+
+    public void setCookies(Cookie accessTokenCookie, Cookie refreshTokenCookie) {
+        this.accessTokenCookie = accessTokenCookie;
+        this.refreshTokenCookie = refreshTokenCookie;
+    }
+
+    /**
+     * Add the access token and refresh token as cookies to the response after successful authentication.
+     *
+     * @param response the response to add them to.
+     */
+    void addCookiesTo(HttpServletResponse response) {
+        response.addCookie(getAccessTokenCookie());
+        response.addCookie(getRefreshTokenCookie());
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/OAuth2SignatureVerifierClient.java

@@ -0,0 +1,23 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import org.springframework.security.jwt.crypto.sign.SignatureVerifier;
+
+/**
+ * Abstracts how to create a SignatureVerifier to verify JWT tokens with a public key.
+ * Implementations will have to contact the OAuth2 authorization server to fetch the public key
+ * and use it to build a SignatureVerifier in a server specific way.
+ *
+ * @see UaaSignatureVerifierClient
+ */
+public interface OAuth2SignatureVerifierClient {
+    /**
+     * Returns the SignatureVerifier used to verify JWT tokens.
+     * Fetches the public key from the Authorization server to create
+     * this verifier.
+     *
+     * @return the new verifier used to verify JWT signatures.
+     * Will be null if we cannot contact the token endpoint.
+     * @throws Exception if we could not create a SignatureVerifier or contact the token endpoint.
+     */
+    SignatureVerifier getSignatureVerifier() throws Exception;
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/OAuth2TokenEndpointClient.java

@@ -0,0 +1,32 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+
+/**
+ * Client talking to an OAuth2 Authorization server token endpoint.
+ *
+ * @see UaaTokenEndpointClient
+ * @see OAuth2TokenEndpointClientAdapter
+ */
+public interface OAuth2TokenEndpointClient {
+    /**
+     * Send a password grant to the token endpoint.
+     *
+     * @param username the username to authenticate.
+     * @param password his password.
+     * @return the access token and enclosed refresh token received from the token endpoint.
+     * @throws org.springframework.security.oauth2.common.exceptions.ClientAuthenticationException
+     * if we cannot contact the token endpoint.
+     */
+    OAuth2AccessToken sendPasswordGrant(String username, String password);
+
+    /**
+     * Send a refresh_token grant to the token endpoint.
+     *
+     * @param refreshTokenValue the refresh token used to get new tokens.
+     * @return the new access/refresh token pair.
+     * @throws org.springframework.security.oauth2.common.exceptions.ClientAuthenticationException
+     * if we cannot contact the token endpoint.
+     */
+    OAuth2AccessToken sendRefreshGrant(String refreshTokenValue);
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/OAuth2TokenEndpointClientAdapter.java

@@ -0,0 +1,120 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import com.baeldung.jhipster.gateway.config.oauth2.OAuth2Properties;
+import io.github.jhipster.config.JHipsterProperties;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+import org.springframework.security.oauth2.common.exceptions.InvalidClientException;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.RestTemplate;
+
+/**
+ * Default base class for an OAuth2TokenEndpointClient.
+ * Individual implementations for a particular OAuth2 provider can use this as a starting point.
+ */
+public abstract class OAuth2TokenEndpointClientAdapter implements OAuth2TokenEndpointClient {
+    private final Logger log = LoggerFactory.getLogger(OAuth2TokenEndpointClientAdapter.class);
+    protected final RestTemplate restTemplate;
+    protected final JHipsterProperties jHipsterProperties;
+    protected final OAuth2Properties oAuth2Properties;
+
+    public OAuth2TokenEndpointClientAdapter(RestTemplate restTemplate, JHipsterProperties jHipsterProperties, OAuth2Properties oAuth2Properties) {
+        this.restTemplate = restTemplate;
+        this.jHipsterProperties = jHipsterProperties;
+        this.oAuth2Properties = oAuth2Properties;
+    }
+
+    /**
+     * Sends a password grant to the token endpoint.
+     *
+     * @param username the username to authenticate.
+     * @param password his password.
+     * @return the access token.
+     */
+    @Override
+    public OAuth2AccessToken sendPasswordGrant(String username, String password) {
+        HttpHeaders reqHeaders = new HttpHeaders();
+        reqHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+        MultiValueMap<String, String> formParams = new LinkedMultiValueMap<>();
+        formParams.set("username", username);
+        formParams.set("password", password);
+        formParams.set("grant_type", "password");
+        addAuthentication(reqHeaders, formParams);
+        HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<>(formParams, reqHeaders);
+        log.debug("contacting OAuth2 token endpoint to login user: {}", username);
+        ResponseEntity<OAuth2AccessToken>
+            responseEntity = restTemplate.postForEntity(getTokenEndpoint(), entity, OAuth2AccessToken.class);
+        if (responseEntity.getStatusCode() != HttpStatus.OK) {
+            log.debug("failed to authenticate user with OAuth2 token endpoint, status: {}", responseEntity.getStatusCodeValue());
+            throw new HttpClientErrorException(responseEntity.getStatusCode());
+        }
+        OAuth2AccessToken accessToken = responseEntity.getBody();
+        return accessToken;
+    }
+
+    /**
+     * Sends a refresh grant to the token endpoint using the current refresh token to obtain new tokens.
+     *
+     * @param refreshTokenValue the refresh token to use to obtain new tokens.
+     * @return the new, refreshed access token.
+     */
+    @Override
+    public OAuth2AccessToken sendRefreshGrant(String refreshTokenValue) {
+        MultiValueMap<String, String> params = new LinkedMultiValueMap<>();
+        params.add("grant_type", "refresh_token");
+        params.add("refresh_token", refreshTokenValue);
+        HttpHeaders headers = new HttpHeaders();
+        addAuthentication(headers, params);
+        HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<>(params, headers);
+        log.debug("contacting OAuth2 token endpoint to refresh OAuth2 JWT tokens");
+        ResponseEntity<OAuth2AccessToken> responseEntity = restTemplate.postForEntity(getTokenEndpoint(), entity,
+                                                                                      OAuth2AccessToken.class);
+        if (responseEntity.getStatusCode() != HttpStatus.OK) {
+            log.debug("failed to refresh tokens: {}", responseEntity.getStatusCodeValue());
+            throw new HttpClientErrorException(responseEntity.getStatusCode());
+        }
+        OAuth2AccessToken accessToken = responseEntity.getBody();
+        log.info("refreshed OAuth2 JWT cookies using refresh_token grant");
+        return accessToken;
+    }
+
+    protected abstract void addAuthentication(HttpHeaders reqHeaders, MultiValueMap<String, String> formParams);
+
+    protected String getClientSecret() {
+        String clientSecret = oAuth2Properties.getWebClientConfiguration().getSecret();
+        if (clientSecret == null) {
+            throw new InvalidClientException("no client-secret configured in application properties");
+        }
+        return clientSecret;
+    }
+
+    protected String getClientId() {
+        String clientId = oAuth2Properties.getWebClientConfiguration().getClientId();
+        if (clientId == null) {
+            throw new InvalidClientException("no client-id configured in application properties");
+        }
+        return clientId;
+    }
+
+    /**
+     * Returns the configured OAuth2 token endpoint URI.
+     *
+     * @return the OAuth2 token endpoint URI.
+     */
+    protected String getTokenEndpoint() {
+        String tokenEndpointUrl = jHipsterProperties.getSecurity().getClientAuthorization().getAccessTokenUri();
+        if (tokenEndpointUrl == null) {
+            throw new InvalidClientException("no token endpoint configured in application properties");
+        }
+        return tokenEndpointUrl;
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/UaaSignatureVerifierClient.java

@@ -0,0 +1,63 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import com.baeldung.jhipster.gateway.config.oauth2.OAuth2Properties;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.security.jwt.crypto.sign.RsaVerifier;
+import org.springframework.security.jwt.crypto.sign.SignatureVerifier;
+import org.springframework.security.oauth2.common.exceptions.InvalidClientException;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.Map;
+
+/**
+ * Client fetching the public key from UAA to create a SignatureVerifier.
+ */
+@Component
+public class UaaSignatureVerifierClient implements OAuth2SignatureVerifierClient {
+    private final Logger log = LoggerFactory.getLogger(UaaSignatureVerifierClient.class);
+    private final RestTemplate restTemplate;
+    protected final OAuth2Properties oAuth2Properties;
+
+    public UaaSignatureVerifierClient(DiscoveryClient discoveryClient, @Qualifier("loadBalancedRestTemplate") RestTemplate restTemplate,
+                                  OAuth2Properties oAuth2Properties) {
+        this.restTemplate = restTemplate;
+        this.oAuth2Properties = oAuth2Properties;
+        // Load available UAA servers
+        discoveryClient.getServices();
+    }
+
+    /**
+     * Fetches the public key from the UAA.
+     *
+     * @return the public key used to verify JWT tokens; or null.
+     */
+    @Override
+    public SignatureVerifier getSignatureVerifier() throws Exception {
+        try {
+            HttpEntity<Void> request = new HttpEntity<Void>(new HttpHeaders());
+            String key = (String) restTemplate
+                .exchange(getPublicKeyEndpoint(), HttpMethod.GET, request, Map.class).getBody()
+                .get("value");
+            return new RsaVerifier(key);
+        } catch (IllegalStateException ex) {
+            log.warn("could not contact UAA to get public key");
+            return null;
+        }
+    }
+
+    /** Returns the configured endpoint URI to retrieve the public key. */
+    private String getPublicKeyEndpoint() {
+        String tokenEndpointUrl = oAuth2Properties.getSignatureVerification().getPublicKeyEndpointUri();
+        if (tokenEndpointUrl == null) {
+            throw new InvalidClientException("no token endpoint configured in application properties");
+        }
+        return tokenEndpointUrl;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/oauth2/UaaTokenEndpointClient.java

@@ -0,0 +1,40 @@
+package com.baeldung.jhipster.gateway.security.oauth2;
+
+import com.baeldung.jhipster.gateway.config.oauth2.OAuth2Properties;
+import io.github.jhipster.config.JHipsterProperties;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.http.HttpHeaders;
+import org.springframework.stereotype.Component;
+import org.springframework.util.Base64Utils;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import java.nio.charset.StandardCharsets;
+
+/**
+ * Client talking to UAA's token endpoint to do different OAuth2 grants.
+ */
+@Component
+public class UaaTokenEndpointClient extends OAuth2TokenEndpointClientAdapter implements OAuth2TokenEndpointClient {
+
+    public UaaTokenEndpointClient(@Qualifier("loadBalancedRestTemplate") RestTemplate restTemplate,
+                                  JHipsterProperties jHipsterProperties, OAuth2Properties oAuth2Properties) {
+        super(restTemplate, jHipsterProperties, oAuth2Properties);
+    }
+
+    @Override
+    protected void addAuthentication(HttpHeaders reqHeaders, MultiValueMap<String, String> formParams) {
+        reqHeaders.add("Authorization", getAuthorizationHeader());
+    }
+
+    /**
+     * @return a Basic authorization header to be used to talk to UAA.
+     */
+    protected String getAuthorizationHeader() {
+        String clientId = getClientId();
+        String clientSecret = getClientSecret();
+        String authorization = clientId + ":" + clientSecret;
+        return "Basic " + Base64Utils.encodeToString(authorization.getBytes(StandardCharsets.UTF_8));
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/security/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Spring Security configuration.
+ */
+package com.baeldung.jhipster.gateway.security;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/service/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Service layer beans.
+ */
+package com.baeldung.jhipster.gateway.service;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/filter/RefreshTokenFilter.java

@@ -0,0 +1,118 @@
+package com.baeldung.jhipster.gateway.web.filter;
+
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2AuthenticationService;
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2CookieHelper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+import org.springframework.security.oauth2.common.exceptions.ClientAuthenticationException;
+import org.springframework.security.oauth2.common.exceptions.InvalidTokenException;
+import org.springframework.security.oauth2.common.exceptions.UnauthorizedClientException;
+import org.springframework.security.oauth2.provider.token.TokenStore;
+import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.filter.GenericFilterBean;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Filters incoming requests and refreshes the access token before it expires.
+ */
+public class RefreshTokenFilter extends GenericFilterBean {
+    /**
+     * Number of seconds before expiry to start refreshing access tokens so we don't run into race conditions when forwarding
+     * requests downstream. Otherwise, access tokens may still be valid when we check here but may then be expired
+     * when relayed to another microservice a wee bit later.
+     */
+    private static final int REFRESH_WINDOW_SECS = 30;
+
+    private final Logger log = LoggerFactory.getLogger(RefreshTokenFilter.class);
+
+    /**
+     * The OAuth2AuthenticationService is doing the actual work. We are just a simple filter after all.
+     */
+    private final OAuth2AuthenticationService authenticationService;
+    private final TokenStore tokenStore;
+
+    public RefreshTokenFilter(OAuth2AuthenticationService authenticationService, TokenStore tokenStore) {
+        this.authenticationService = authenticationService;
+        this.tokenStore = tokenStore;
+    }
+
+    /**
+     * Check access token cookie and refresh it, if it is either not present, expired or about to expire.
+     */
+    @Override
+    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
+        throws IOException, ServletException {
+        HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
+        HttpServletResponse httpServletResponse = (HttpServletResponse) servletResponse;
+        try {
+            httpServletRequest = refreshTokensIfExpiring(httpServletRequest, httpServletResponse);
+        } catch (ClientAuthenticationException ex) {
+            log.warn("Security exception: could not refresh tokens", ex);
+            httpServletRequest = authenticationService.stripTokens(httpServletRequest);
+        }
+        filterChain.doFilter(httpServletRequest, servletResponse);
+    }
+
+    /**
+     * Refresh the access and refresh tokens if they are about to expire.
+     *
+     * @param httpServletRequest  the servlet request holding the current cookies. If no refresh cookie is present,
+     *                            then we are out of luck.
+     * @param httpServletResponse the servlet response that gets the new set-cookie headers, if they had to be
+     *                            refreshed.
+     * @return a new request to use downstream that contains the new cookies, if they had to be refreshed.
+     * @throws InvalidTokenException if the tokens could not be refreshed.
+     */
+    public HttpServletRequest refreshTokensIfExpiring(HttpServletRequest httpServletRequest, HttpServletResponse
+        httpServletResponse) {
+        HttpServletRequest newHttpServletRequest = httpServletRequest;
+        //get access token from cookie
+        Cookie accessTokenCookie = OAuth2CookieHelper.getAccessTokenCookie(httpServletRequest);
+        if (mustRefreshToken(accessTokenCookie)) {        //we either have no access token, or it is expired, or it is about to expire
+            //get the refresh token cookie and, if present, request new tokens
+            Cookie refreshCookie = OAuth2CookieHelper.getRefreshTokenCookie(httpServletRequest);
+            if (refreshCookie != null) {
+                try {
+                    newHttpServletRequest = authenticationService.refreshToken(httpServletRequest, httpServletResponse, refreshCookie);
+                } catch (HttpClientErrorException ex) {
+                    throw new UnauthorizedClientException("could not refresh OAuth2 token", ex);
+                }
+            } else if (accessTokenCookie != null) {
+                log.warn("access token found, but no refresh token, stripping them all");
+                OAuth2AccessToken token = tokenStore.readAccessToken(accessTokenCookie.getValue());
+                if (token.isExpired()) {
+                    throw new InvalidTokenException("access token has expired, but there's no refresh token");
+                }
+            }
+        }
+        return newHttpServletRequest;
+    }
+
+    /**
+     * Check if we must refresh the access token.
+     * We must refresh it, if we either have no access token, or it is expired, or it is about to expire.
+     *
+     * @param accessTokenCookie the current access token.
+     * @return true, if it must be refreshed; false, otherwise.
+     */
+    private boolean mustRefreshToken(Cookie accessTokenCookie) {
+        if (accessTokenCookie == null) {
+            return true;
+        }
+        OAuth2AccessToken token = tokenStore.readAccessToken(accessTokenCookie.getValue());
+        //check if token is expired or about to expire
+        if (token.isExpired() || token.getExpiresIn() < REFRESH_WINDOW_SECS) {
+            return true;
+        }
+        return false;       //access token is still fine
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/filter/RefreshTokenFilterConfigurer.java

@@ -0,0 +1,36 @@
+package com.baeldung.jhipster.gateway.web.filter;
+
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2AuthenticationService;
+
+import org.springframework.security.config.annotation.SecurityConfigurerAdapter;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.oauth2.provider.authentication.OAuth2AuthenticationProcessingFilter;
+import org.springframework.security.oauth2.provider.token.TokenStore;
+import org.springframework.security.web.DefaultSecurityFilterChain;
+
+/**
+ * Configures a RefreshTokenFilter to refresh access tokens if they are about to expire.
+ *
+ * @see RefreshTokenFilter
+ */
+public class RefreshTokenFilterConfigurer extends SecurityConfigurerAdapter<DefaultSecurityFilterChain, HttpSecurity> {
+    /**
+     * RefreshTokenFilter needs the OAuth2AuthenticationService to refresh cookies using the refresh token.
+     */
+    private OAuth2AuthenticationService authenticationService;
+    private final TokenStore tokenStore;
+
+    public RefreshTokenFilterConfigurer(OAuth2AuthenticationService authenticationService, TokenStore tokenStore) {
+        this.authenticationService = authenticationService;
+        this.tokenStore = tokenStore;
+    }
+
+    /**
+     * Install RefreshTokenFilter as a servlet Filter.
+     */
+    @Override
+    public void configure(HttpSecurity http) throws Exception {
+        RefreshTokenFilter customFilter = new RefreshTokenFilter(authenticationService, tokenStore);
+        http.addFilterBefore(customFilter, OAuth2AuthenticationProcessingFilter.class);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/AuthResource.java

@@ -0,0 +1,68 @@
+package com.baeldung.jhipster.gateway.web.rest;
+
+import com.codahale.metrics.annotation.Timed;
+import com.baeldung.jhipster.gateway.security.oauth2.OAuth2AuthenticationService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.util.Map;
+
+/**
+ * Authentication endpoint for web client.
+ * Used to authenticate a user using OAuth2 access tokens or log him out.
+ *
+ * @author markus.oellinger
+ */
+@RestController
+@RequestMapping("/auth")
+public class AuthResource {
+
+    private final Logger log = LoggerFactory.getLogger(AuthResource.class);
+
+    private OAuth2AuthenticationService authenticationService;
+
+    public AuthResource(OAuth2AuthenticationService authenticationService) {
+        this.authenticationService = authenticationService;
+    }
+
+    /**
+     * Authenticates a user setting the access and refresh token cookies.
+     *
+     * @param request  the HttpServletRequest holding - among others - the headers passed from the client.
+     * @param response the HttpServletResponse getting the cookies set upon successful authentication.
+     * @param params   the login params (username, password, rememberMe).
+     * @return the access token of the authenticated user. Will return an error code if it fails to authenticate the user.
+     */
+    @RequestMapping(value = "/login", method = RequestMethod.POST, consumes = MediaType
+        .APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
+    @Timed
+    public ResponseEntity<OAuth2AccessToken> authenticate(HttpServletRequest request, HttpServletResponse response, @RequestBody
+        Map<String, String> params) {
+        return authenticationService.authenticate(request, response, params);
+    }
+
+    /**
+     * Logout current user deleting his cookies.
+     *
+     * @param request  the HttpServletRequest holding - among others - the headers passed from the client.
+     * @param response the HttpServletResponse getting the cookies set upon successful authentication.
+     * @return an empty response entity.
+     */
+    @RequestMapping(value = "/logout", method = RequestMethod.POST)
+    @Timed
+    public ResponseEntity<?> logout(HttpServletRequest request, HttpServletResponse response) {
+        log.info("logging out user {}", SecurityContextHolder.getContext().getAuthentication().getName());
+        authenticationService.logout(request, response);
+        return ResponseEntity.noContent().build();
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/GatewayResource.java

@@ -0,0 +1,54 @@
+package com.baeldung.jhipster.gateway.web.rest;
+
+import com.baeldung.jhipster.gateway.web.rest.vm.RouteVM;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.netflix.zuul.filters.Route;
+import org.springframework.cloud.netflix.zuul.filters.RouteLocator;
+import org.springframework.http.*;
+import org.springframework.security.access.annotation.Secured;
+import com.baeldung.jhipster.gateway.security.AuthoritiesConstants;
+import org.springframework.web.bind.annotation.*;
+
+import com.codahale.metrics.annotation.Timed;
+
+/**
+ * REST controller for managing Gateway configuration.
+ */
+@RestController
+@RequestMapping("/api/gateway")
+public class GatewayResource {
+
+    private final RouteLocator routeLocator;
+
+    private final DiscoveryClient discoveryClient;
+
+    public GatewayResource(RouteLocator routeLocator, DiscoveryClient discoveryClient) {
+        this.routeLocator = routeLocator;
+        this.discoveryClient = discoveryClient;
+    }
+
+    /**
+     * GET  /routes : get the active routes.
+     *
+     * @return the ResponseEntity with status 200 (OK) and with body the list of routes
+     */
+    @GetMapping("/routes")
+    @Timed
+    @Secured(AuthoritiesConstants.ADMIN)
+    public ResponseEntity<List<RouteVM>> activeRoutes() {
+        List<Route> routes = routeLocator.getRoutes();
+        List<RouteVM> routeVMs = new ArrayList<>();
+        routes.forEach(route -> {
+            RouteVM routeVM = new RouteVM();
+            routeVM.setPath(route.getFullPath());
+            routeVM.setServiceId(route.getId());
+            routeVM.setServiceInstances(discoveryClient.getInstances(route.getLocation()));
+            routeVMs.add(routeVM);
+        });
+        return new ResponseEntity<>(routeVMs, HttpStatus.OK);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/LogsResource.java

@@ -0,0 +1,39 @@
+package com.baeldung.jhipster.gateway.web.rest;
+
+import com.baeldung.jhipster.gateway.web.rest.vm.LoggerVM;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.LoggerContext;
+import com.codahale.metrics.annotation.Timed;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Controller for view and managing Log Level at runtime.
+ */
+@RestController
+@RequestMapping("/management")
+public class LogsResource {
+
+    @GetMapping("/logs")
+    @Timed
+    public List<LoggerVM> getList() {
+        LoggerContext context = (LoggerContext) LoggerFactory.getILoggerFactory();
+        return context.getLoggerList()
+            .stream()
+            .map(LoggerVM::new)
+            .collect(Collectors.toList());
+    }
+
+    @PutMapping("/logs")
+    @ResponseStatus(HttpStatus.NO_CONTENT)
+    @Timed
+    public void changeLevel(@RequestBody LoggerVM jsonLogger) {
+        LoggerContext context = (LoggerContext) LoggerFactory.getILoggerFactory();
+        context.getLogger(jsonLogger.getName()).setLevel(Level.valueOf(jsonLogger.getLevel()));
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/BadRequestAlertException.java

@@ -0,0 +1,42 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import org.zalando.problem.AbstractThrowableProblem;
+import org.zalando.problem.Status;
+
+import java.net.URI;
+import java.util.HashMap;
+import java.util.Map;
+
+public class BadRequestAlertException extends AbstractThrowableProblem {
+
+    private static final long serialVersionUID = 1L;
+
+    private final String entityName;
+
+    private final String errorKey;
+
+    public BadRequestAlertException(String defaultMessage, String entityName, String errorKey) {
+        this(ErrorConstants.DEFAULT_TYPE, defaultMessage, entityName, errorKey);
+    }
+
+    public BadRequestAlertException(URI type, String defaultMessage, String entityName, String errorKey) {
+        super(type, defaultMessage, Status.BAD_REQUEST, null, null, null, getAlertParameters(entityName, errorKey));
+        this.entityName = entityName;
+        this.errorKey = errorKey;
+    }
+
+    public String getEntityName() {
+        return entityName;
+    }
+
+    public String getErrorKey() {
+        return errorKey;
+    }
+
+    private static Map<String, Object> getAlertParameters(String entityName, String errorKey) {
+        Map<String, Object> parameters = new HashMap<>();
+        parameters.put("message", "error." + errorKey);
+        parameters.put("params", entityName);
+        return parameters;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/CustomParameterizedException.java

@@ -0,0 +1,54 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import org.zalando.problem.AbstractThrowableProblem;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.zalando.problem.Status.BAD_REQUEST;
+
+/**
+ * Custom, parameterized exception, which can be translated on the client side.
+ * For example:
+ *
+ * <pre>
+ * throw new CustomParameterizedException(&quot;myCustomError&quot;, &quot;hello&quot;, &quot;world&quot;);
+ * </pre>
+ *
+ * Can be translated with:
+ *
+ * <pre>
+ * "error.myCustomError" :  "The server says {{param0}} to {{param1}}"
+ * </pre>
+ */
+public class CustomParameterizedException extends AbstractThrowableProblem {
+
+    private static final long serialVersionUID = 1L;
+
+    private static final String PARAM = "param";
+
+    public CustomParameterizedException(String message, String... params) {
+        this(message, toParamMap(params));
+    }
+
+    public CustomParameterizedException(String message, Map<String, Object> paramMap) {
+        super(ErrorConstants.PARAMETERIZED_TYPE, "Parameterized Exception", BAD_REQUEST, null, null, null, toProblemParameters(message, paramMap));
+    }
+
+    public static Map<String, Object> toParamMap(String... params) {
+        Map<String, Object> paramMap = new HashMap<>();
+        if (params != null && params.length > 0) {
+            for (int i = 0; i < params.length; i++) {
+                paramMap.put(PARAM + i, params[i]);
+            }
+        }
+        return paramMap;
+    }
+
+    public static Map<String, Object> toProblemParameters(String message, Map<String, Object> paramMap) {
+        Map<String, Object> parameters = new HashMap<>();
+        parameters.put("message", message);
+        parameters.put("params", paramMap);
+        return parameters;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/EmailAlreadyUsedException.java

@@ -0,0 +1,10 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+public class EmailAlreadyUsedException extends BadRequestAlertException {
+
+    private static final long serialVersionUID = 1L;
+
+    public EmailAlreadyUsedException() {
+        super(ErrorConstants.EMAIL_ALREADY_USED_TYPE, "Email is already in use!", "userManagement", "emailexists");
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/EmailNotFoundException.java

@@ -0,0 +1,13 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import org.zalando.problem.AbstractThrowableProblem;
+import org.zalando.problem.Status;
+
+public class EmailNotFoundException extends AbstractThrowableProblem {
+
+    private static final long serialVersionUID = 1L;
+
+    public EmailNotFoundException() {
+        super(ErrorConstants.EMAIL_NOT_FOUND_TYPE, "Email address not registered", Status.BAD_REQUEST);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/ErrorConstants.java

@@ -0,0 +1,21 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import java.net.URI;
+
+public final class ErrorConstants {
+
+    public static final String ERR_CONCURRENCY_FAILURE = "error.concurrencyFailure";
+    public static final String ERR_VALIDATION = "error.validation";
+    public static final String PROBLEM_BASE_URL = "https://www.jhipster.tech/problem";
+    public static final URI DEFAULT_TYPE = URI.create(PROBLEM_BASE_URL + "/problem-with-message");
+    public static final URI CONSTRAINT_VIOLATION_TYPE = URI.create(PROBLEM_BASE_URL + "/constraint-violation");
+    public static final URI PARAMETERIZED_TYPE = URI.create(PROBLEM_BASE_URL + "/parameterized");
+    public static final URI ENTITY_NOT_FOUND_TYPE = URI.create(PROBLEM_BASE_URL + "/entity-not-found");
+    public static final URI INVALID_PASSWORD_TYPE = URI.create(PROBLEM_BASE_URL + "/invalid-password");
+    public static final URI EMAIL_ALREADY_USED_TYPE = URI.create(PROBLEM_BASE_URL + "/email-already-used");
+    public static final URI LOGIN_ALREADY_USED_TYPE = URI.create(PROBLEM_BASE_URL + "/login-already-used");
+    public static final URI EMAIL_NOT_FOUND_TYPE = URI.create(PROBLEM_BASE_URL + "/email-not-found");
+
+    private ErrorConstants() {
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/ExceptionTranslator.java

@@ -0,0 +1,107 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import com.baeldung.jhipster.gateway.web.rest.util.HeaderUtil;
+
+import org.springframework.dao.ConcurrencyFailureException;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.BindingResult;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.zalando.problem.DefaultProblem;
+import org.zalando.problem.Problem;
+import org.zalando.problem.ProblemBuilder;
+import org.zalando.problem.Status;
+import org.zalando.problem.spring.web.advice.ProblemHandling;
+import org.zalando.problem.violations.ConstraintViolationProblem;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import javax.servlet.http.HttpServletRequest;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.stream.Collectors;
+
+/**
+ * Controller advice to translate the server side exceptions to client-friendly json structures.
+ * The error response follows RFC7807 - Problem Details for HTTP APIs (https://tools.ietf.org/html/rfc7807)
+ */
+@ControllerAdvice
+public class ExceptionTranslator implements ProblemHandling {
+
+    /**
+     * Post-process the Problem payload to add the message key for the front-end if needed
+     */
+    @Override
+    public ResponseEntity<Problem> process(@Nullable ResponseEntity<Problem> entity, NativeWebRequest request) {
+        if (entity == null) {
+            return entity;
+        }
+        Problem problem = entity.getBody();
+        if (!(problem instanceof ConstraintViolationProblem || problem instanceof DefaultProblem)) {
+            return entity;
+        }
+        ProblemBuilder builder = Problem.builder()
+            .withType(Problem.DEFAULT_TYPE.equals(problem.getType()) ? ErrorConstants.DEFAULT_TYPE : problem.getType())
+            .withStatus(problem.getStatus())
+            .withTitle(problem.getTitle())
+            .with("path", request.getNativeRequest(HttpServletRequest.class).getRequestURI());
+
+        if (problem instanceof ConstraintViolationProblem) {
+            builder
+                .with("violations", ((ConstraintViolationProblem) problem).getViolations())
+                .with("message", ErrorConstants.ERR_VALIDATION);
+        } else {
+            builder
+                .withCause(((DefaultProblem) problem).getCause())
+                .withDetail(problem.getDetail())
+                .withInstance(problem.getInstance());
+            problem.getParameters().forEach(builder::with);
+            if (!problem.getParameters().containsKey("message") && problem.getStatus() != null) {
+                builder.with("message", "error.http." + problem.getStatus().getStatusCode());
+            }
+        }
+        return new ResponseEntity<>(builder.build(), entity.getHeaders(), entity.getStatusCode());
+    }
+
+    @Override
+    public ResponseEntity<Problem> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, @Nonnull NativeWebRequest request) {
+        BindingResult result = ex.getBindingResult();
+        List<FieldErrorVM> fieldErrors = result.getFieldErrors().stream()
+            .map(f -> new FieldErrorVM(f.getObjectName(), f.getField(), f.getCode()))
+            .collect(Collectors.toList());
+
+        Problem problem = Problem.builder()
+            .withType(ErrorConstants.CONSTRAINT_VIOLATION_TYPE)
+            .withTitle("Method argument not valid")
+            .withStatus(defaultConstraintViolationStatus())
+            .with("message", ErrorConstants.ERR_VALIDATION)
+            .with("fieldErrors", fieldErrors)
+            .build();
+        return create(ex, problem, request);
+    }
+
+    @ExceptionHandler
+    public ResponseEntity<Problem> handleNoSuchElementException(NoSuchElementException ex, NativeWebRequest request) {
+        Problem problem = Problem.builder()
+            .withStatus(Status.NOT_FOUND)
+            .with("message", ErrorConstants.ENTITY_NOT_FOUND_TYPE)
+            .build();
+        return create(ex, problem, request);
+    }
+
+    @ExceptionHandler
+    public ResponseEntity<Problem> handleBadRequestAlertException(BadRequestAlertException ex, NativeWebRequest request) {
+        return create(ex, request, HeaderUtil.createFailureAlert(ex.getEntityName(), ex.getErrorKey(), ex.getMessage()));
+    }
+
+    @ExceptionHandler
+    public ResponseEntity<Problem> handleConcurrencyFailure(ConcurrencyFailureException ex, NativeWebRequest request) {
+        Problem problem = Problem.builder()
+            .withStatus(Status.CONFLICT)
+            .with("message", ErrorConstants.ERR_CONCURRENCY_FAILURE)
+            .build();
+        return create(ex, problem, request);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/FieldErrorVM.java

@@ -0,0 +1,33 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import java.io.Serializable;
+
+public class FieldErrorVM implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    private final String objectName;
+
+    private final String field;
+
+    private final String message;
+
+    public FieldErrorVM(String dto, String field, String message) {
+        this.objectName = dto;
+        this.field = field;
+        this.message = message;
+    }
+
+    public String getObjectName() {
+        return objectName;
+    }
+
+    public String getField() {
+        return field;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/InternalServerErrorException.java

@@ -0,0 +1,16 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import org.zalando.problem.AbstractThrowableProblem;
+import org.zalando.problem.Status;
+
+/**
+ * Simple exception with a message, that returns an Internal Server Error code.
+ */
+public class InternalServerErrorException extends AbstractThrowableProblem {
+
+    private static final long serialVersionUID = 1L;
+
+    public InternalServerErrorException(String message) {
+        super(ErrorConstants.DEFAULT_TYPE, message, Status.INTERNAL_SERVER_ERROR);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/InvalidPasswordException.java

@@ -0,0 +1,13 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+import org.zalando.problem.AbstractThrowableProblem;
+import org.zalando.problem.Status;
+
+public class InvalidPasswordException extends AbstractThrowableProblem {
+
+    private static final long serialVersionUID = 1L;
+
+    public InvalidPasswordException() {
+        super(ErrorConstants.INVALID_PASSWORD_TYPE, "Incorrect password", Status.BAD_REQUEST);
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/LoginAlreadyUsedException.java

@@ -0,0 +1,10 @@
+package com.baeldung.jhipster.gateway.web.rest.errors;
+
+public class LoginAlreadyUsedException extends BadRequestAlertException {
+
+    private static final long serialVersionUID = 1L;
+
+    public LoginAlreadyUsedException() {
+        super(ErrorConstants.LOGIN_ALREADY_USED_TYPE, "Login name already used!", "userManagement", "userexists");
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/errors/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Specific errors used with Zalando's "problem-spring-web" library.
+ *
+ * More information on https://github.com/zalando/problem-spring-web
+ */
+package com.baeldung.jhipster.gateway.web.rest.errors;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Spring MVC REST controllers.
+ */
+package com.baeldung.jhipster.gateway.web.rest;

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/util/HeaderUtil.java

@@ -0,0 +1,45 @@
+package com.baeldung.jhipster.gateway.web.rest.util;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpHeaders;
+
+/**
+ * Utility class for HTTP headers creation.
+ */
+public final class HeaderUtil {
+
+    private static final Logger log = LoggerFactory.getLogger(HeaderUtil.class);
+
+    private static final String APPLICATION_NAME = "gatewayApp";
+
+    private HeaderUtil() {
+    }
+
+    public static HttpHeaders createAlert(String message, String param) {
+        HttpHeaders headers = new HttpHeaders();
+        headers.add("X-" + APPLICATION_NAME + "-alert", message);
+        headers.add("X-" + APPLICATION_NAME + "-params", param);
+        return headers;
+    }
+
+    public static HttpHeaders createEntityCreationAlert(String entityName, String param) {
+        return createAlert(APPLICATION_NAME + "." + entityName + ".created", param);
+    }
+
+    public static HttpHeaders createEntityUpdateAlert(String entityName, String param) {
+        return createAlert(APPLICATION_NAME + "." + entityName + ".updated", param);
+    }
+
+    public static HttpHeaders createEntityDeletionAlert(String entityName, String param) {
+        return createAlert(APPLICATION_NAME + "." + entityName + ".deleted", param);
+    }
+
+    public static HttpHeaders createFailureAlert(String entityName, String errorKey, String defaultMessage) {
+        log.error("Entity processing failed, {}", defaultMessage);
+        HttpHeaders headers = new HttpHeaders();
+        headers.add("X-" + APPLICATION_NAME + "-error", "error." + errorKey);
+        headers.add("X-" + APPLICATION_NAME + "-params", entityName);
+        return headers;
+    }
+}

jhipster/jhipster-uaa/gateway/src/main/java/com/baeldung/jhipster/gateway/web/rest/util/PaginationUtil.java

@@ -0,0 +1,45 @@
+package com.baeldung.jhipster.gateway.web.rest.util;
+
+import org.springframework.data.domain.Page;
+import org.springframework.http.HttpHeaders;
+import org.springframework.web.util.UriComponentsBuilder;
+
+/**
+ * Utility class for handling pagination.
+ *
+ * <p>
+ * Pagination uses the same principles as the <a href="https://developer.github.com/v3/#pagination">GitHub API</a>,
+ * and follow <a href="http://tools.ietf.org/html/rfc5988">RFC 5988 (Link header)</a>.
+ */
+public final class PaginationUtil {
+
+    private PaginationUtil() {
+    }
+
+    public static <T> HttpHeaders generatePaginationHttpHeaders(Page<T> page, String baseUrl) {
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.add("X-Total-Count", Long.toString(page.getTotalElements()));
+        String link = "";
+        if ((page.getNumber() + 1) < page.getTotalPages()) {
+            link = "<" + generateUri(baseUrl, page.getNumber() + 1, page.getSize()) + ">; rel=\"next\",";
+        }
+        // prev link
+        if ((page.getNumber()) > 0) {
+            link += "<" + generateUri(baseUrl, page.getNumber() - 1, page.getSize()) + ">; rel=\"prev\",";
+        }
+        // last and first link
+        int lastPage = 0;
+        if (page.getTotalPages() > 0) {
+            lastPage = page.getTotalPages() - 1;
+        }
+        link += "<" + generateUri(baseUrl, lastPage, page.getSize()) + ">; rel=\"last\",";
+        link += "<" + generateUri(baseUrl, 0, page.getSize()) + ">; rel=\"first\"";
+        headers.add(HttpHeaders.LINK, link);
+        return headers;
+    }
+
+    private static String generateUri(String baseUrl, int page, int size) {
+        return UriComponentsBuilder.fromUriString(baseUrl).queryParam("page", page).queryParam("size", size).toUriString();
+    }
+}