[java] Programmatically shut down Spring Boot application

How can I programmatically shutdown a Spring Boot application without terminating the VM?

In other works, what is the opposite of

new SpringApplication(Main.class).run(args);

In the application you can use SpringApplication. This has a static exit() method that takes two arguments: the ApplicationContext and an ExitCodeGenerator:

i.e. you can declare this method:

@Autowired
public void shutDown(ExecutorServiceExitCodeGenerator exitCodeGenerator) {
    SpringApplication.exit(applicationContext, exitCodeGenerator);
}

Inside the Integration tests you can achieved it by adding @DirtiesContext annotation at class level:

• @DirtiesContext(classMode=ClassMode.AFTER_CLASS) - The associated ApplicationContext will be marked as dirty after the test class.
• @DirtiesContext(classMode=ClassMode.AFTER_EACH_TEST_METHOD) - The associated ApplicationContext will be marked as dirty after each test method in the class.

i.e.

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = {Application.class},
    webEnvironment= SpringBootTest.WebEnvironment.DEFINED_PORT, properties = {"server.port:0"})
@DirtiesContext(classMode= DirtiesContext.ClassMode.AFTER_CLASS)
public class ApplicationIT {
...

This works, even done is printed.

  SpringApplication.run(MyApplication.class, args).close();
  System.out.println("done");

So adding .close() after run()

Explanation:

public ConfigurableApplicationContext run(String... args)

Run the Spring application, creating and refreshing a new ApplicationContext. Parameters:

args - the application arguments (usually passed from a Java main method)

Returns: a running ApplicationContext

and:

void close() Close this application context, releasing all resources and locks that the implementation might hold. This includes destroying all cached singleton beans. Note: Does not invoke close on a parent context; parent contexts have their own, independent lifecycle.

This method can be called multiple times without side effects: Subsequent close calls on an already closed context will be ignored.

So basically, it will not close the parent context, that's why the VM doesn't quit.

This will make sure that the SpringBoot application is closed properly and the resources are released back to the operating system,

@Autowired
private ApplicationContext context;

@GetMapping("/shutdown-app")
public void shutdownApp() {

    int exitCode = SpringApplication.exit(context, (ExitCodeGenerator) () -> 0);
    System.exit(exitCode);
}

The simplest way would be to inject the following object where you need to initiate the shutdown

ShutdownManager.java

import org.springframework.context.ApplicationContext;
import org.springframework.boot.SpringApplication;

@Component
class ShutdownManager {

    @Autowired
    private ApplicationContext appContext;

    /*
     * Invoke with `0` to indicate no error or different code to indicate
     * abnormal exit. es: shutdownManager.initiateShutdown(0);
     **/
    public void initiateShutdown(int returnCode){
        SpringApplication.exit(appContext, () -> returnCode);
    }
}