[JAVA-27376] Moved article "Programmatically Restarting a Spring Boot… (#15412)

* [JAVA-27376] Moved article "Programmatically Restarting a Spring Boot Application" to spring-boot-runtime-2 module

* [JAVA-27367]

spring-boot-modules/spring-boot-runtime-2/README.md

@@ -5,3 +5,6 @@ This module contains articles about administering a Spring Boot runtime
 ### Relevant Articles:									
  - [Configure the Heap Size When Starting a Spring Boot Application](https://www.baeldung.com/spring-boot-heap-size)
  - [Max-HTTP-Header-Size in Spring Boot 2](https://www.baeldung.com/spring-boot-max-http-header-size)
+ - [Programmatically Restarting a Spring Boot Application](https://www.baeldung.com/java-restart-spring-boot-app)
+
+ - More articles: [[<-- prev]](../spring-boot-runtime)

spring-boot-modules/spring-boot-runtime-2/pom.xml

@@ -28,6 +28,15 @@
             <groupId>org.springframework.security</groupId>
             <artifactId>spring-security-test</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter</artifactId>
+            <version>${springcloud.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -64,4 +73,7 @@
         </plugins>
     </build>
 
+    <properties>
+        <springcloud.version>3.1.3</springcloud.version>
+    </properties>
 </project>

spring-boot-modules/spring-boot-runtime-2/src/main/java/com/baeldung/restart/Application.java

@@ -0,0 +1,30 @@
+package com.baeldung.restart;
+
+import org.springframework.boot.ApplicationArguments;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
+
+@SpringBootApplication
+public class Application extends SpringBootServletInitializer {   
+
+    private static ConfigurableApplicationContext context;
+
+    public static void main(String[] args) {
+        context = SpringApplication.run(Application.class, args);
+    }
+
+    public static void restart() {
+        ApplicationArguments args = context.getBean(ApplicationArguments.class);
+
+        Thread thread = new Thread(() -> {
+            context.close();
+            context = SpringApplication.run(Application.class, args.getSourceArgs());
+        });
+
+        thread.setDaemon(false);
+        thread.start();
+    }
+
+}

spring-boot-modules/spring-boot-runtime-2/src/main/java/com/baeldung/restart/RestartController.java

@@ -0,0 +1,23 @@
+package com.baeldung.restart;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class RestartController {
+    
+    @Autowired
+    private RestartService restartService;
+    
+    @PostMapping("/restart")
+    public void restart() {
+        Application.restart();
+    }
+    
+    @PostMapping("/restartApp")
+    public void restartUsingActuator() {
+        restartService.restartApp();
+    }
+    
+}

spring-boot-modules/spring-boot-runtime-2/src/main/java/com/baeldung/restart/RestartService.java

@@ -0,0 +1,17 @@
+package com.baeldung.restart;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cloud.context.restart.RestartEndpoint;
+import org.springframework.stereotype.Service;
+
+@Service
+public class RestartService {
+    
+    @Autowired
+    private RestartEndpoint restartEndpoint;
+    
+    public void restartApp() {
+        restartEndpoint.restart();
+    }
+
+}

spring-boot-modules/spring-boot-runtime-2/src/main/resources/application.properties

@@ -0,0 +1,7 @@
+management.endpoints.web.exposure.include=*
+management.metrics.enable.root=true
+management.metrics.enable.jvm=true
+management.endpoint.restart.enabled=true
+spring.datasource.jmx-enabled=false
+spring.jmx.enabled=true
+management.endpoint.shutdown.enabled=true

spring-boot-modules/spring-boot-runtime-2/src/test/java/com/baeldung/restart/RestartApplicationManualTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.restart;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.ResponseEntity;
+
+/**
+ * We have to make sure that while running this test, 8080 and 8090 ports are free.
+ * Otherwise it will fail.
+ */
+public class RestartApplicationManualTest {
+
+    private TestRestTemplate restTemplate = new TestRestTemplate();
+
+    @Test
+    public void givenBootApp_whenRestart_thenOk() throws Exception {
+        Application.main(new String[0]);
+
+        ResponseEntity response = restTemplate.exchange("http://localhost:8080/restart",
+           HttpMethod.POST, null, Object.class);
+        
+        assertEquals(200, response.getStatusCode().value());
+    }
+    
+    @Test
+    public void givenBootApp_whenRestartUsingActuator_thenOk() throws Exception {
+        Application.main(new String[] { "--server.port=8090" });
+
+        ResponseEntity response = restTemplate.exchange("http://localhost:8090/restartApp",
+           HttpMethod.POST, null, Object.class);
+        
+        assertEquals(200, response.getStatusCode().value());
+    }
+
+}