Spring:如何在初始化应用后启动逻辑

Question

我已经实现了这个逻辑

@Component
public class SomeUpdater {

    @Autowired
    private ApplicationEventPublisher applicationEventPublisher;
    private ExecutorService executorService;

    @PostConstruct
    public void init(){
        executorService = Executors.newSingleThreadExecutor();
        executorService.execute(()->{
            //some logic
            applicationEventPublisher.publishEvent(new PurposeEvent(this, 5));
        });
    }

}

@Component
public class SomeClass {

    @EventListener
    public void update(PurposeEvent purposeEvent){
        //update
    }
}

但我可以从日志中看到，update (PurposeEvent purposeEvent)侦听器的初始化时间晚于applicationEventPublisher.publishEvent(new PurposeEvent(this, 5));方法的调用时间。初始化后如何调用逻辑？我尝试为ContextRefreshedEvent使用@EventListener，但据我所知，它可以被多次调用

Answer 1

您可以使用@DependsOn注释，这可以强制Spring容器在使用@DependsOn注释的bean之前初始化一个或多个bean。然后，您将确保在SomeUpdater之前初始化SomeClass。

长期解决方案是：

1. Spring Boot启动挂钩
2. Spring事件类型，如ApplicationStartedEvent、ApplicationReadyEvent.

有用的链接：http://dolszewski.com/spring/running-code-on-spring-boot-startup/ http://javainfinite.com/spring-boot/springboot-applicationreadyevent-applicationfailedevent-contextrefreshedevent/

Answer 2

您可以使用spring事件，如下所示：

@EventListener(ApplicationReadyEvent.class)
public void init() {
    final ExecutorService executorService = Executors.newSingleThreadExecutor();
    executorService.execute(() -> {
        //some logic
        applicationEventPublisher.publishEvent(new PurposeEvent(this, 5));
    });
}