SpringBoot中SmartLifecycle的使用解析

public class TestSmartLifecycle implements SmartLifecycle {
   
  @Override
    public void start() {
        System.out.println("TestSmartLifecycle is start");
    }
//SmartLifecycle组件停止后的回调，程序被异步关闭
    @Override
    public void stop() {
        System.out.println("SmartLifecycle is stop");
    }
//为false，并且isAutoStartup为true，执行start方法
//为true，执行stop方法。
    @Override
    public boolean isRunning() {
        return false;
    }
//如果为true，实现了SmartLifecycle 接口的组件，能再ApplicationContext已经刷新的时候，自动执行start方法，
    @Override
    public boolean isAutoStartup() {
        return true;
    }
//当running为true时，再应用关闭时会执行stop(Runnable callback)方法,
如果再执行完stop后，running没有设置为false时，应用会卡住一段时间，无法退出
    @Override
    public void stop(Runnable callback) {
        System.out.println("TestSmartLifecycle is stop");
        callback.run();
    }
 
    @Override
    public int getPhase() {
        return 0;
    }
}

@Configuration
public class TestConfiguration {
 
    @Bean
    TestSmartLifecycle testSmartLifecycle(){
        return new TestSmartLifecycle();
    }
}

private void startBeans(boolean autoStartupOnly) {
		Map<String, Lifecycle> lifecycleBeans = getLifecycleBeans();
		Map<Integer, LifecycleGroup> phases = new HashMap<>();
		lifecycleBeans.forEach((beanName, bean) -> {
			if (!autoStartupOnly || (bean instanceof SmartLifecycle && ((SmartLifecycle) bean).isAutoStartup())) {
				int phase = getPhase(bean);
				LifecycleGroup group = phases.get(phase);
				if (group == null) {
					group = new LifecycleGroup(phase, this.timeoutPerShutdownPhase, lifecycleBeans, autoStartupOnly);
					phases.put(phase, group);
				}
				group.add(beanName, bean);
			}
		});
		if (!phases.isEmpty()) {
			List<Integer> keys = new ArrayList<>(phases.keySet());
			Collections.sort(keys);
			for (Integer key : keys) {
				phases.get(key).start();
			}
		}
	}