Spring Boot关闭endpoint应该关闭整个JVM进程，还是仅仅关闭应用程序上下文？

Answer 1

感谢Stéphane，我找到了阻止JVM进程在到达/shutdownendpoint后终止的原因。在我的一个依赖项中有一个ScheduledExecutor没有随应用程序上下文关闭，它阻止JVM进程关闭（即使在应用程序上下文关闭之后）。我写了一个简单的例子来展示如何再现该行为，还有一个例子展示如何解析它。

当您命中/关闭endpoint时，此示例不会终止JVM进程：

@SpringBootApplication
public class AppSpringConfiguration {

    public static void main(String[] args) {
        SpringApplication.run(AppSpringConfiguration.class);
    }

    @Bean
    public ClassWithExecutor ce() {
        return new ClassWithExecutor();
    }

    @PostConstruct
    public void startScheduledTask() {
        ce().startScheduledTask();
    }

    @RestController
    public static class BusinessLogicController {

        @RequestMapping(value = "/hi")
        public String businessLogic() {
            return "hi";
        }
    }            

    public static class ClassWithExecutor {
        ScheduledExecutorService es;

        ClassWithExecutor() {
            this.es = Executors.newSingleThreadScheduledExecutor();
        }

        public void startScheduledTask() {
            es.scheduleAtFixedRate(new Runnable() {
                @Override
                public void run() {
                    System.out.println("Printing this every minute");
                }
            }, 0, 3, TimeUnit.SECONDS);
        }    
    }
}

通过添加在应用程序上下文关闭时关闭ScheduledExecutor的shutdown钩子,JVM进程现在在到达/shutdownendpoint后被终止：

@SpringBootApplication
public class AppSpringConfiguration {

    public static void main(String[] args) {
        SpringApplication.run(AppSpringConfiguration.class);
    }

    @Bean
    public ClassWithExecutor ce() {
        return new ClassWithExecutor();
    }

    @Bean
    ShutdownAction sa() {
        return new ShutdownAction(ce());
    }

    @PostConstruct
    public void startScheduledTask() {
        ce().startScheduledTask();
    }

    @RestController
    public static class BusinessLogicController {

        @RequestMapping(value = "/hi")
        public String businessLogic() {
            return "hi";
        }
    }

    public static class ShutdownAction implements ApplicationListener<ContextClosedEvent> {
        private ClassWithExecutor classWithExecutor;

        ShutdownAction(ClassWithExecutor classWithExecutor) {
            this.classWithExecutor = classWithExecutor;
        }

        @Override
        public void onApplicationEvent(ContextClosedEvent event) {
            classWithExecutor.shutdown();
        }
    }

    public static class ClassWithExecutor {
        ScheduledExecutorService es;

        ClassWithExecutor() {
            this.es = Executors.newSingleThreadScheduledExecutor();
        }

        public void startScheduledTask() {
            es.scheduleAtFixedRate(new Runnable() {
                @Override
                public void run() {
                    System.out.println("Printing this every minute");
                }
            }, 0, 3, TimeUnit.SECONDS);
        }

        public void shutdown() {
            es.shutdownNow();
        }
    }
}