SpringBoot2.3如何优雅停机

@RestController
public class DemoController {
 @GetMapping("/demo")
 public String demo() throws InterruptedException {
  // 模拟业务耗时处理流程
  Thread.sleep(20 * 1000L);
  return "hello";
 }
}

/**
 * Configuration for shutting down a {@link WebServer}.
 *
 * @author Andy Wilkinson
 * @since 2.3.0
 */
public enum Shutdown {

 /**
  * 优雅停机 （限期停机）
  *
  */
 GRACEFUL,

 /**
  * 立即停机
  */
 IMMEDIATE;

}

//ApplicationContext
 @Override
 public void registerShutdownHook() {
  if (this.shutdownHook == null) {
   // No shutdown hook registered yet.
   this.shutdownHook = new Thread(SHUTDOWN_HOOK_THREAD_NAME) {
    @Override
    public void run() {
     synchronized (startupShutdownMonitor) {
      doClose();
     }
    }
   };
   Runtime.getRuntime().addShutdownHook(this.shutdownHook);
  }
 }

@Endpoint(id = "shutdown", enableByDefault = false)
public class ShutdownEndpoint implements ApplicationContextAware {

 @WriteOperation
 public Map<String, String> shutdown() {
  Thread thread = new Thread(this::performShutdown);
  thread.setContextClassLoader(getClass().getClassLoader());
  thread.start();
 }

 private void performShutdown() {
  try {
   Thread.sleep(500L);
  }
  catch (InterruptedException ex) {
   Thread.currentThread().interrupt();
  }

  // 此处close 逻辑和上边 shutdownhook 的处理一样
  this.context.close();
 }
}