BAEL-6179: Add Actuator sample without Spring Boot (#14032)

* BAEL-6179: Add Actuator sample without Spring Boot

* BAEL-6179: Simplify custom health indicator

parent-spring-6/README.md

@@ -0,0 +1,3 @@
+## Parent Spring 5
+
+This is a parent module for all projects using Spring 5

parent-spring-6/pom.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         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">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>parent-spring-6</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>parent-spring-6</name>
+    <packaging>pom</packaging>
+    <description>Parent for all spring 6 core modules</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework</groupId>
+                <artifactId>spring-framework-bom</artifactId>
+                <version>${spring.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-core</artifactId>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <spring.version>6.0.8</spring.version>
+    </properties>
+
+</project>

pom.xml

@@ -331,6 +331,7 @@
                 <module>parent-boot-2</module>
                 <module>parent-spring-4</module>
                 <module>parent-spring-5</module>
+                <module>parent-spring-6</module>
                 <module>parent-java</module>
 
                 <module>checker-framework</module>
@@ -408,6 +409,7 @@
                 <module>parent-boot-2</module>
                 <module>parent-spring-4</module>
                 <module>parent-spring-5</module>
+                <module>parent-spring-6</module>
                 <module>parent-java</module>
 
                 <module>spring-4</module>
@@ -468,6 +470,7 @@
                 <module>parent-boot-2</module>
                 <module>parent-spring-4</module>
                 <module>parent-spring-5</module>
+                <module>parent-spring-6</module>
                 <module>parent-java</module>
 
                 <module>apache-spark</module>
@@ -509,6 +512,7 @@
                 <module>parent-boot-2</module>
                 <module>parent-spring-4</module>
                 <module>parent-spring-5</module>
+                <module>parent-spring-6</module>
                 <module>parent-java</module>
 
                 <module>checker-framework</module>
@@ -577,6 +581,7 @@
                 <module>parent-boot-2</module>
                 <module>parent-spring-4</module>
                 <module>parent-spring-5</module>
+                <module>parent-spring-6</module>
                 <module>parent-java</module>
 
                 <module>spring-4</module>
@@ -629,6 +634,7 @@
                 <module>parent-boot-2</module>
                 <module>parent-spring-4</module>
                 <module>parent-spring-5</module>
+                <module>parent-spring-6</module>
                 <module>parent-java</module>
 
                 <module>apache-spark</module>
@@ -896,6 +902,7 @@
                 <module>spring-5-webflux</module>
                 <module>spring-5-webflux-2</module>
                 <module>spring-activiti</module>
+                <module>spring-actuator</module>
                 <module>spring-core-2</module>
                 <module>spring-core-3</module>
                 <module>spring-credhub</module>
@@ -1201,6 +1208,7 @@
                 <module>parent-boot-2</module>
                 <module>parent-spring-4</module>
                 <module>parent-spring-5</module>
+                <module>parent-spring-6</module>
                 <module>parent-java</module>
             </modules>
 

spring-actuator/pom.xml

@@ -0,0 +1,75 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    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">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-actuator</artifactId>
+    <name>spring-actuator</name>
+    <packaging>war</packaging>
+    <description>Demo project for Spring Boot Actuator without Spring Boot</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-spring-6</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-spring-6</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>jakarta.servlet</groupId>
+            <artifactId>jakarta.servlet-api</artifactId>
+            <version>5.0.0</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webmvc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-actuator-autoconfigure</artifactId>
+            <version>${spring-boot.version}</version>
+        </dependency>
+        <!-- Jetty embedded -->
+        <dependency>
+            <groupId>org.eclipse.jetty</groupId>
+            <artifactId>jetty-servlet</artifactId>
+            <version>${jetty.version}</version>
+        </dependency>
+    </dependencies>
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-war-plugin</artifactId>
+                    <version>3.3.2</version>
+                </plugin>
+                <!-- to run the server, use mvn jetty:run -->
+                <plugin>
+                    <groupId>org.eclipse.jetty</groupId>
+                    <artifactId>jetty-maven-plugin</artifactId>
+                    <version>${jetty.version}</version>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+        <plugins>
+            <plugin>
+                <groupId>org.eclipse.jetty</groupId>
+                <artifactId>jetty-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <spring-boot.version>3.0.6</spring-boot.version>
+        <jetty.version>11.0.15</jetty.version>
+    </properties>
+
+</project>

spring-actuator/src/main/java/com/baeldung/spring/actuator/ActuatorConfiguration.java

@@ -0,0 +1,26 @@
+package com.baeldung.spring.actuator;
+
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.info.InfoContributor;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class ActuatorConfiguration {
+
+    @Bean
+    public HealthIndicator sampleHealthIndicator() {
+        return Health.up()
+          .withDetail("info", "Sample Health")
+          ::build;
+    }
+
+    @Bean
+    public InfoContributor provideSampleInfos() {
+        return builder ->
+          builder
+            .withDetail("app-title", "Actuator Sample Application");
+
+    }
+}

spring-actuator/src/main/java/com/baeldung/spring/actuator/AppConfig.java

@@ -0,0 +1,11 @@
+package com.baeldung.spring.actuator;
+
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.PropertySource;
+
+@EnableAutoConfiguration
+@PropertySource("classpath:application.properties")
+@ComponentScan(basePackageClasses = AppConfig.class)
+public class AppConfig {
+}

spring-actuator/src/main/java/com/baeldung/spring/actuator/Start.java

@@ -0,0 +1,64 @@
+package com.baeldung.spring.actuator;
+
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.web.context.ContextLoaderListener;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
+import org.springframework.web.servlet.DispatcherServlet;
+
+public class Start {
+
+    private static final Logger logger = LoggerFactory.getLogger(Start.class);
+    private static final int DEFAULT_PORT = 8080;
+    private static final String CONTEXT_PATH = "/";
+    private static final String CONFIG_LOCATION = AppConfig.class.getName();
+    private static final String MAPPING_URL = "/*";
+
+    /*
+     * This application runs a Jetty webcontainer that runs the
+     * Spring Dispatcher Servlet.
+     */
+    public static void main(String[] args) throws Exception {
+        new Start().startJetty(getPortFromArgs(args));
+    }
+
+    private static int getPortFromArgs(String[] args) {
+        if (args.length > 0) {
+            try {
+                return Integer.parseInt(args[0]);
+            } catch (NumberFormatException ignore) {
+            }
+        }
+        logger.info("No server port configured, falling back to {}", DEFAULT_PORT);
+        return DEFAULT_PORT;
+    }
+
+    private void startJetty(int port) throws Exception {
+        logger.info("Starting server at port {}", port);
+        Server server = new Server(port);
+        server.setHandler(getServletContextHandler(getContext()));
+        server.start();
+        logger.info("Server started at port {}", port);
+        server.join();
+    }
+
+    private static ServletContextHandler getServletContextHandler(WebApplicationContext context) {
+        ServletContextHandler contextHandler = new ServletContextHandler();
+        contextHandler.setErrorHandler(null);
+        contextHandler.setContextPath(CONTEXT_PATH);
+        contextHandler.addServlet(new ServletHolder(new DispatcherServlet(context)), MAPPING_URL);
+        contextHandler.addEventListener(new ContextLoaderListener(context));
+        return contextHandler;
+    }
+
+    private static WebApplicationContext getContext() {
+        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
+        context.setConfigLocation(CONFIG_LOCATION);
+        return context;
+    }
+
+}

spring-actuator/src/main/java/com/baeldung/spring/actuator/WebMvcConfiguration.java

@@ -0,0 +1,23 @@
+package com.baeldung.spring.actuator;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class WebMvcConfiguration {
+
+    @Bean
+    public WebMvcConfigurer webMvcConfigurer() {
+        return new WebMvcConfigurer() {
+            @Override
+            public void addViewControllers(ViewControllerRegistry registry) {
+                registry
+                  .addViewController("/")
+                  .setViewName("redirect:/actuator");
+            }
+        };
+    }
+
+}

spring-actuator/src/main/resources/application.properties

@@ -0,0 +1,2 @@
+management.endpoints.web.exposure.include=*
+management.endpoint.health.show-details=always