Merge pull request #4480 from tinomthomas/master

Spring shutdown callback methodologies - BAEL 1831

spring-boot/src/main/java/com/baeldung/shutdownhooks/ShutdownHookApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung.shutdownhooks;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+@EnableAutoConfiguration
+public class ShutdownHookApplication {
+
+    public static void main(String args[]) {
+        SpringApplication.run(ShutdownHookApplication.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/beans/Bean1.java

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+package com.baeldung.shutdownhooks.beans;
+
+import javax.annotation.PreDestroy;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class Bean1 {
+
+    @PreDestroy
+    public void destroy() {
+        System.out.println("Shutdown triggered using @PreDestroy.");
+    }
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/beans/Bean2.java

@@ -0,0 +1,14 @@
+package com.baeldung.shutdownhooks.beans;
+
+import org.springframework.beans.factory.DisposableBean;
+import org.springframework.stereotype.Component;
+
+@Component
+public class Bean2 implements DisposableBean {
+
+    @Override
+    public void destroy() throws Exception {
+        System.out.println("Shutdown triggered using DisposableBean.");
+    }
+
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/beans/Bean3.java

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+package com.baeldung.shutdownhooks.beans;
+
+public class Bean3 {
+
+    public void destroy() {
+        System.out.println("Shutdown triggered using bean destroy method.");
+    }
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/config/ExampleServletContextListener.java

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+package com.baeldung.shutdownhooks.config;
+
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+
+public class ExampleServletContextListener implements ServletContextListener {
+
+    @Override
+    public void contextDestroyed(ServletContextEvent event) {
+        System.out.println("Shutdown triggered using ServletContextListener.");
+    }
+
+    @Override
+    public void contextInitialized(ServletContextEvent event) {
+        // Triggers when context initializes
+    }
+
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/config/ShutdownHookConfiguration.java

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+package com.baeldung.shutdownhooks.config;
+
+import javax.servlet.ServletContextListener;
+
+import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.baeldung.shutdownhooks.beans.Bean3;
+
+@Configuration
+public class ShutdownHookConfiguration {
+
+    @Bean(destroyMethod = "destroy")
+    public Bean3 initializeBean3() {
+        return new Bean3();
+    }
+
+    @Bean
+    ServletListenerRegistrationBean<ServletContextListener> servletListener() {
+        ServletListenerRegistrationBean<ServletContextListener> srb = new ServletListenerRegistrationBean<>();
+        srb.setListener(new ExampleServletContextListener());
+        return srb;
+    }
+}