Merge branch 'master' of https://github.com/raksha-rao/tutorials

core-java-8/src/main/java/com/baeldung/spliteratorAPI/RelatedAuthorSpliterator.java

@@ -2,46 +2,48 @@ package com.baeldung.spliteratorAPI;
 
 import java.util.List;
 import java.util.Spliterator;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
 
 public class RelatedAuthorSpliterator implements Spliterator<Author> {
-    private final List<Author> list;
+	private final List<Author> list;
-    private int current = 0;
+	AtomicInteger current = new AtomicInteger();
 
-    public RelatedAuthorSpliterator(List<Author> list) {
+	public RelatedAuthorSpliterator(List<Author> list) {
-        this.list = list;
+		this.list = list;
-    }
+	}
 
-    @Override
+	@Override
-    public boolean tryAdvance(Consumer<? super Author> action) {
+	public boolean tryAdvance(Consumer<? super Author> action) {
-        action.accept(list.get(current++));
-        return current < list.size();
-    }
 
-    @Override
+		action.accept(list.get(current.getAndIncrement()));
-    public Spliterator<Author> trySplit() {
+		return current.get() < list.size();
-        int currentSize = list.size() - current;
+	}
-        if (currentSize < 10) {
-            return null;
-        }
-        for (int splitPos = currentSize / 2 + current; splitPos < list.size(); splitPos++) {
-            if (list.get(splitPos)
-                .getRelatedArticleId() == 0) {
-                Spliterator<Author> spliterator = new RelatedAuthorSpliterator(list.subList(current, splitPos));
-                current = splitPos;
-                return spliterator;
-            }
-        }
-        return null;
-    }
 
-    @Override
+	@Override
-    public long estimateSize() {
+	public Spliterator<Author> trySplit() {
-        return list.size() - current;
+		int currentSize = list.size() - current.get();
-    }
+		if (currentSize < 10) {
+			return null;
+		}
+		for (int splitPos = currentSize / 2 + current.intValue(); splitPos < list.size(); splitPos++) {
+			if (list.get(splitPos).getRelatedArticleId() == 0) {
+				Spliterator<Author> spliterator = new RelatedAuthorSpliterator(list.subList(current.get(), splitPos));
+				current.set(splitPos);
+				return spliterator;
+			}
+		}
+		return null;
+	}
+
+	@Override
+	public long estimateSize() {
+		return list.size() - current.get();
+	}
+
+	@Override
+	public int characteristics() {
+		return CONCURRENT;
+	}
 
-    @Override
-    public int characteristics() {
-        return SIZED + CONCURRENT;
-    }
 }

spring-5-reactive/src/main/java/com/baeldung/reactive/websocket/ReactiveJavaClientWebSocket.java

@@ -2,22 +2,25 @@ package com.baeldung.reactive.websocket;
 
 import java.net.URI;
 import java.time.Duration;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.client.ReactorNettyWebSocketClient;
 import org.springframework.web.reactive.socket.client.WebSocketClient;
 
 import reactor.core.publisher.Mono;
 
-@SpringBootApplication
 public class ReactiveJavaClientWebSocket {
-    public static void main(String[] args) throws InterruptedException {
+	public static void main(String[] args) throws InterruptedException {
+		  
         WebSocketClient client = new ReactorNettyWebSocketClient();
-        client.execute(URI.create("ws://localhost:8080/event-emitter"), session ->  session.send(Mono.just(session.textMessage("event-me-from-spring-reactive-client")))
+        client.execute(
+          URI.create("ws://localhost:8080/event-emitter"), 
+          session -> session.send(
+            Mono.just(session.textMessage("event-spring-reactive-client-websocket")))
             .thenMany(session.receive()
-                .map(WebSocketMessage::getPayloadAsText)
+              .map(WebSocketMessage::getPayloadAsText)
-                .log())
+              .log())
             .then())
             .block(Duration.ofSeconds(10L));
     }
+
 }

spring-5-reactive/src/main/java/com/baeldung/reactive/websocket/ReactiveWebSocketHandler.java

@@ -12,7 +12,6 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-import javax.annotation.PostConstruct;
 import java.time.Duration;
 import java.time.LocalDateTime;
 import java.util.UUID;
@@ -20,37 +19,18 @@ import java.util.UUID;
 @Component
 public class ReactiveWebSocketHandler implements WebSocketHandler {
 
-    private Flux<Event> eventFlux;
+    private Flux<Event> eventFlux = Flux.generate(e -> {
-    private Flux<Event> intervalFlux;
+        Event event = new Event(UUID.randomUUID().toString(), LocalDateTime.now().toString());
+        e.next(event);
+    });
 
-    /**
+    private Flux<Event> intervalFlux = Flux.interval(Duration.ofMillis(1000L)).zipWith(eventFlux, (time, event) -> event);
-     * Here we prepare a Flux that will emit a message every second
-     */
-    @PostConstruct
-    private void init() throws InterruptedException {
 
-        eventFlux = Flux.generate(e -> {
+    private ObjectMapper json = new ObjectMapper();
-            Event event = new Event(UUID.randomUUID()
-                .toString(),
-                LocalDateTime.now()
-                    .toString());
-            e.next(event);
-        });
 
-        intervalFlux = Flux.interval(Duration.ofMillis(1000L))
-            .zipWith(eventFlux, (time, event) -> event);
-
-    }
-
-    /**
-     * On each new client session, send the message flux to the client.
-     * Spring subscribes to the flux and send every new flux event to the WebSocketSession object
-     * @param session
-     * @return Mono<Void>
-     */
     @Override
     public Mono<Void> handle(WebSocketSession webSocketSession) {
-        ObjectMapper json = new ObjectMapper();
+
         return webSocketSession.send(intervalFlux.map(event -> {
             try {
                 String jsonEvent = json.writeValueAsString(event);
@@ -60,12 +40,9 @@ public class ReactiveWebSocketHandler implements WebSocketHandler {
                 e.printStackTrace();
                 return "";
             }
-        })
+        }).map(webSocketSession::textMessage))
-            .map(webSocketSession::textMessage))
 
-            .and(webSocketSession.receive()
+                .and(webSocketSession.receive().map(WebSocketMessage::getPayloadAsText).log());
-                .map(WebSocketMessage::getPayloadAsText)
-                .log());
     }
 
 }

spring-cloud/README.md

@@ -12,13 +12,11 @@
 
   Client-side service discovery allows services to find and communicate with each other without hardcoding hostname and port. The only ‘fixed point’ in such an architecture consists of a service registry with which each service has to register.
 
+### Relevant Articles:
 - [Intro to Spring Cloud Netflix - Hystrix](http://www.baeldung.com/spring-cloud-netflix-hystrix)
 - [Dockerizing a Spring Boot Application](http://www.baeldung.com/dockerizing-spring-boot-application)
 - [Introduction to Spring Cloud Rest Client with Netflix Ribbon](http://www.baeldung.com/spring-cloud-rest-client-with-netflix-ribbon)
 - [A Quick Guide to Spring Cloud Consul](http://www.baeldung.com/spring-cloud-consul)
-
-### Relevant Articles:
-- [Introduction to Spring Cloud Rest Client with Netflix Ribbon](http://www.baeldung.com/spring-cloud-rest-client-with-netflix-ribbon)
 - [An Introduction to Spring Cloud Zookeeper](http://www.baeldung.com/spring-cloud-zookeeper)
+- [Using a Spring Cloud App Starter](http://www.baeldung.com/using-a-spring-cloud-app-starter)
 - [Spring Cloud Connectors and Heroku](http://www.baeldung.com/spring-cloud-heroku)
-

spring-cloud/spring-cloud-stream-starters/bash/hadoop.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+
+# For Ubuntu 14.04
+# Inspired from: https://github.com/curran/setupHadoop/blob/master/setupHadoop.sh
+# Use from the user directory
+
+# Install Java
+sudo apt-get update
+sudo add-apt-repository -y ppa:webupd8team/java
+sudo apt-get install -y oracle-java8-installer
+
+# Install Hadoop
+curl -O http://mirror.cogentco.com/pub/apache/hadoop/common/hadoop-2.8.2/hadoop-2.8.2.tar.gz
+tar xfz hadoop-2.8.2.tar.gz
+sudo mv hadoop-2.8.2 /usr/local/hadoop
+rm hadoop-2.8.2.tar.gz
+
+# Environmental Variables
+echo export JAVA_HOME=/usr/lib/jvm/java-8-oracle >> ~/.bashrc
+echo export HADOOP_PREFIX=/usr/local/hadoop >> ~/.bashrc
+echo export PATH=\$PATH:/usr/local/hadoop/bin >> ~/.bashrc
+echo export PATH=\$PATH:/usr/local/hadoop/sbin >> ~/.bashrc
+source ~/.bashrc
+
+# Copy configuration files
+cp master/* /usr/local/hadoop/etc/hadoop/
+
+# Format HDFS
+hdfs namenode -format
+
+# SSH keys for Hadoop to use.
+ssh-keygen -t rsa -P 'password' -f ~/.ssh/id_rsa.pub
+sudo mv ~/.ssh/id_rsa.pub ~/.ssh/authorized_keys
+
+# SSH
+ssh localhost
+# authenticate with osboxes.org
+
+# Start NameNode daemon and DataNode daemon
+start-dfs.sh
+# stop-dfs.sh
+
+# Install Maven
+sudo apt-get install maven
+
+# Access Hadoop - http://localhost:50070

spring-cloud/spring-cloud-stream-starters/boot/.gitignore

@@ -0,0 +1,3 @@
+.idea
+*/target/*
+*.iml

spring-cloud/spring-cloud-stream-starters/boot/pom.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+         xmlns="http://maven.apache.org/POM/4.0.0">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.twitterhdfs</groupId>
+    <artifactId>twitterhdfs</artifactId>
+    <packaging>jar</packaging>
+    <version>1.0.0</version>
+
+    <name>twitterhdfs</name>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>1.5.8.RELEASE</version>
+    </parent>
+
+    <dependencies>
+        <!-- Spring Stream Starter Apps -->
+        <dependency>
+            <groupId>org.springframework.cloud.stream.app</groupId>
+            <artifactId>spring-cloud-starter-stream-source-twitterstream</artifactId>
+            <version>1.3.1.RELEASE</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud.stream.app</groupId>
+            <artifactId>spring-cloud-starter-stream-sink-hdfs</artifactId>
+            <version>1.3.1.RELEASE</version>
+        </dependency>
+
+        <!-- JSTL/JSP -->
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>jstl</artifactId>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+        <finalName>twitterhdfs</finalName>
+    </build>
+</project>

spring-cloud/spring-cloud-stream-starters/boot/src/main/java/com/baeldung/twitterhdfs/aggregate/AggregateApp.java

@@ -0,0 +1,18 @@
+package com.baeldung.twitterhdfs.aggregate;
+
+import com.baeldung.twitterhdfs.processor.ProcessorApp;
+import com.baeldung.twitterhdfs.source.SourceApp;
+import com.baeldung.twitterhdfs.sink.SinkApp;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.stream.aggregate.AggregateApplicationBuilder;
+
+@SpringBootApplication
+public class AggregateApp {
+    public static void main(String[] args) {
+        new AggregateApplicationBuilder()
+                .from(SourceApp.class).args("--fixedDelay=5000")
+                .via(ProcessorApp.class)
+                .to(SinkApp.class).args("--debug=true")
+                .run(args);
+    }
+}

spring-cloud/spring-cloud-stream-starters/boot/src/main/java/com/baeldung/twitterhdfs/processor/ProcessorApp.java

@@ -0,0 +1,20 @@
+package com.baeldung.twitterhdfs.processor;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.stream.annotation.EnableBinding;
+import org.springframework.cloud.stream.messaging.Processor;
+import org.springframework.integration.annotation.Transformer;
+
+@SpringBootApplication
+@EnableBinding(Processor.class)
+public class ProcessorApp {
+    Logger log = LoggerFactory.getLogger(ProcessorApp.class);
+
+    @Transformer(inputChannel = Processor.INPUT, outputChannel = Processor.OUTPUT)
+    public String processMessage(String payload) {
+        log.info("Payload received!");
+        return payload;
+    }
+}

spring-cloud/spring-cloud-stream-starters/boot/src/main/java/com/baeldung/twitterhdfs/sink/SinkApp.java

@@ -0,0 +1,22 @@
+package com.baeldung.twitterhdfs.sink;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.stream.annotation.EnableBinding;
+import org.springframework.cloud.stream.app.hdfs.sink.HdfsSinkConfiguration;
+import org.springframework.cloud.stream.messaging.Sink;
+import org.springframework.context.annotation.Import;
+import org.springframework.integration.annotation.ServiceActivator;
+
+@SpringBootApplication
+@EnableBinding(Sink.class)
+@Import(HdfsSinkConfiguration.class)
+public class SinkApp {
+    Logger log = LoggerFactory.getLogger(SinkApp.class);
+
+    @ServiceActivator(inputChannel= Sink.INPUT)
+    public void loggerSink(Object payload) {
+        log.info("Received: " + payload);
+    }
+}

spring-cloud/spring-cloud-stream-starters/boot/src/main/java/com/baeldung/twitterhdfs/source/SourceApp.java

@@ -0,0 +1,26 @@
+package com.baeldung.twitterhdfs.source;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.stream.annotation.EnableBinding;
+import org.springframework.cloud.stream.app.twitterstream.source.TwitterstreamSourceConfiguration;
+import org.springframework.cloud.stream.messaging.Source;
+import org.springframework.context.annotation.Import;
+import org.springframework.integration.annotation.InboundChannelAdapter;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+@SpringBootApplication
+@EnableBinding(Source.class)
+@Import(TwitterstreamSourceConfiguration.class)
+public class SourceApp {
+    Logger log = LoggerFactory.getLogger(SourceApp.class);
+
+    @InboundChannelAdapter(value = Source.OUTPUT)
+    public String timerMessageSource() {
+        return new SimpleDateFormat().format(new Date());
+    }
+
+}

spring-cloud/spring-cloud-stream-starters/boot/src/main/resources/application.properties

@@ -0,0 +1,6 @@
+hdfs.fs-uri=hdfs://127.0.0.1:50010/
+
+twitter.credentials.access-token=
+twitter.credentials.access-token-secret=
+twitter.credentials.consumer-key=
+twitter.credentials.consumer-secret=

spring-cloud/spring-cloud-stream-starters/hdfs/application.properties

@@ -0,0 +1 @@
+hdfs.fs-uri=hdfs://127.0.0.1:50010/

spring-cloud/spring-cloud-stream-starters/hdfs/hdfs.sh

@@ -0,0 +1,11 @@
+# Git spring-cloud-stream-app-starters
+# https://github.com/spring-cloud-stream-app-starters/hdfs/blob/master/spring-cloud-starter-stream-sink-hdfs/README.adoc
+git clone https://github.com/spring-cloud-stream-app-starters/hdfs.git
+
+# Build it
+./mvnw clean install -PgenerateApps
+
+# Run it
+cd apps
+# Optionally inject application.properties prior to build
+java -jar hdfs-sink.jar --fsUri=hdfs://127.0.0.1:50010/

spring-cloud/spring-cloud-stream-starters/twitter/application.properties

@@ -0,0 +1,4 @@
+twitter.credentials.access-token=
+twitter.credentials.access-token-secret=
+twitter.credentials.consumer-key=
+twitter.credentials.consumer-secret=

spring-cloud/spring-cloud-stream-starters/twitter/twitter.sh

@@ -0,0 +1,12 @@
+# Git spring-cloud-stream-app-starters
+# https://github.com/spring-cloud-stream-app-starters/hdfs/blob/master/spring-cloud-starter-stream-sink-hdfs/README.adoc
+git clone https://github.com/spring-cloud-stream-app-starters/twitter.git
+
+# Build it
+./mvnw clean install -PgenerateApps
+
+# Run it
+cd apps
+# Optionally inject application.properties prior to build
+java -jar twitter_stream_source.jar --consumerKey=<CONSUMER_KEY> --consumerSecret=<CONSUMER_SECRET> \
+    --accessToken=<ACCESS_TOKEN> --accessTokenSecret=<ACCESS_TOKEN_SECRET>

spring-mvc-simple/README.md

@@ -2,3 +2,4 @@
 
 - [HandlerAdapters in Spring MVC](http://www.baeldung.com/spring-mvc-handler-adapters)
 - [Template Engines for Spring](http://www.baeldung.com/spring-template-engines)
+- [Spring 5 and Servlet 4 – The PushBuilder](http://www.baeldung.com/spring-5-push)