springboot启动后监听操作

通过springboot启动源码可以得出，我们可以从下面3步开始

• listeners.started(context)
• callRunners(context, applicationArguments);
• listeners.running(context);

public ConfigurableApplicationContext run(String... args) {
		StopWatch stopWatch = new StopWatch();
		stopWatch.start();
		DefaultBootstrapContext bootstrapContext = createBootstrapContext();
		ConfigurableApplicationContext context = null;
		configureHeadlessProperty();
		SpringApplicationRunListeners listeners = getRunListeners(args);
		listeners.starting(bootstrapContext, this.mainApplicationClass);
		try {
			ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
			ConfigurableEnvironment environment = prepareEnvironment(listeners, bootstrapContext, applicationArguments);
			configureIgnoreBeanInfo(environment);
			Banner printedBanner = printBanner(environment);
			context = createApplicationContext();
			context.setApplicationStartup(this.applicationStartup);
			prepareContext(bootstrapContext, context, environment, listeners, applicationArguments, printedBanner);
			refreshContext(context);
			afterRefresh(context, applicationArguments);
			stopWatch.stop();
			if (this.logStartupInfo) {
				new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
			}
			listeners.started(context);
			callRunners(context, applicationArguments);
		}
		catch (Throwable ex) {
			handleRunFailure(context, ex, listeners);
			throw new IllegalStateException(ex);
		}

		try {
			listeners.running(context);
		}
		catch (Throwable ex) {
			handleRunFailure(context, ex, null);
			throw new IllegalStateException(ex);
		}
		return context;
	}

监听器模式

可以在应用中监听：ApplicationStartedEventApplicationReadyEvent事件

@Component
public class ContextListener {

   @EventListener(value = {ApplicationReadyEvent.class})
   public void text(ApplicationReadyEvent event){
      System.err.println("=============================================:"+event);
   }
}

Runner模式

private void callRunners(ApplicationContext context, ApplicationArguments args) {
   List<Object> runners = new ArrayList<>();
   runners.addAll(context.getBeansOfType(ApplicationRunner.class).values());
   runners.addAll(context.getBeansOfType(CommandLineRunner.class).values());
   AnnotationAwareOrderComparator.sort(runners);
   for (Object runner : new LinkedHashSet<>(runners)) {
      if (runner instanceof ApplicationRunner) {
         callRunner((ApplicationRunner) runner, args);
      }
      if (runner instanceof CommandLineRunner) {
         callRunner((CommandLineRunner) runner, args);
      }
   }
}

可以在代码中实现：ApplicationRunner和CommandLineRunner接口

@Component
public class ContextRunner implements ApplicationRunner {
   @Override
   public void run(ApplicationArguments args) throws Exception {
      System.err.println("=============================================:"+args);
   }
}

操作比较简单