一.需求是想将我的写一个方法能在项目启动后就运行,之前使用了redis的消息监听器,感觉可以照着监听器这个思路做,于是想到了sringboot的监听器
二.目前spring boot中支持的事件类型如下
- ApplicationFailedEvent:该事件为spring boot启动失败时的操作
- ApplicationPreparedEvent:上下文context准备时触发
- ApplicationReadyEvent:上下文已经准备完毕的时候触发
- ApplicationStartedEvent:spring boot 启动监听类
- SpringApplicationEvent:获取SpringApplication
- ApplicationEnvironmentPreparedEvent:环境事先准备
三.监听器的使用
第一:首先定义一个自己使用的监听器类并实现ApplicationListener接口。
@Componen
public class MessageReceiver implements ApplicationListener<ApplicationReadyEvent> {
private Logger logger = LoggerFactory.getLogger(MessageReceiver.class);
private UserService userService = null;
@Override
public void onApplicationEvent(ApplicationReadyEvent event) {
ConfigurableApplicationContext applicationContext = event.getApplicationContext();
//解决userService一直为空
userService = applicationContext.getBean(UserService.class);
System.out.println("name"+userService.getName());
}
}
第二:通过SpringApplication类中的addListeners方法将自定义的监听器注册进去
public class Application {
public static void main(String[] args) {
SpringApplication application = new SpringApplication(Application.class);
application.addListeners(new MessageReceiver());
application.run(args);
}
}
启动项目