“Spring Boot”方式是使用CommandLineRunner。只需添加该类型的bean，就可以了。在Spring 4.1 (Boot 1.2)中，也有一个SmartInitializingBean，它在所有东西初始化后得到一个回调。还有SmartLifecycle(来自Spring 3)。

尝试这个方法，它将在应用程序上下文完全启动时运行您的代码。

 @Component
public class OnStartServer implements ApplicationListener<ContextRefreshedEvent> {

    @Override
    public void onApplicationEvent(ContextRefreshedEvent arg0) {
                // EXECUTE YOUR CODE HERE 
    }
}

为什么不创建一个bean，在初始化时启动监视器呢?

@Component
public class Monitor {
    @Autowired private SomeService service

    @PostConstruct
    public void init(){
        // start your monitoring in here
    }
}

在为bean完成任何自动装配之前，不会调用init方法。

你试过ApplicationReadyEvent吗?

@Component
public class ApplicationStartup 
implements ApplicationListener<ApplicationReadyEvent> {

  /**
   * This event is executed as late as conceivably possible to indicate that 
   * the application is ready to service requests.
   */
  @Override
  public void onApplicationEvent(final ApplicationReadyEvent event) {

    // here your code ...

    return;
  }
}

代码来自:http://blog.netgloo.com/2014/11/13/run-code-at-spring-boot-startup/

下面是文档中提到的启动事件:

... Application events are sent in the following order, as your application runs: An ApplicationStartedEvent is sent at the start of a run, but before any processing except the registration of listeners and initializers. An ApplicationEnvironmentPreparedEvent is sent when the Environment to be used in the context is known, but before the context is created. An ApplicationPreparedEvent is sent just before the refresh is started, but after bean definitions have been loaded. An ApplicationReadyEvent is sent after the refresh and any related callbacks have been processed to indicate the application is ready to service requests. An ApplicationFailedEvent is sent if there is an exception on startup. ...

在Spring Boot应用程序启动后执行代码块的最佳方法是使用PostConstruct注释。或者你也可以使用命令行运行器。

1. 使用PostConstruct注释

@Configuration
public class InitialDataConfiguration {

    @PostConstruct
    public void postConstruct() {
        System.out.println("Started after Spring boot application !");
    }

}

2. 使用命令行运行器bean

@Configuration
public class InitialDataConfiguration {

    @Bean
    CommandLineRunner runner() {
        return args -> {
            System.out.println("CommandLineRunner running in the UnsplashApplication class...");
        };
    }
}

Spring引导提供了一个带有run()方法的ApplicationRunner接口，在应用程序启动时调用该方法。 但是，我们有一个ApplicationArguments类的实例，而不是传递给回调方法的原始String参数。

@Component
public class AppStartupRunner implements ApplicationRunner {

    @Override
    public void run(ApplicationArguments args) throws Exception {
        //some logic here
    }
}