Spring boot 添加 自定义Listener (监听器)
Spring boot 添加 自定义Listener (监听器)
自定义监听器需要实现以下监听器接口中的其中一个
Spring MVC 内置的监听器
-
ServletContextListener ServletContextAttributeListener ServletRequestListener ServletRequestAttributeListener HttpSessionListener HttpSessionAttributeListener
注册自定义监听器的三种方式
- 直接创建自定义的监听器，注册为 Sping 组件
将自定义监听器注册为 Spring 组件即可自动触发监听器
@Component
public class MyListener implements ServletRequestListener {
Logger log = LoggerFactory.getLogger(MyListener.class);
@Override
public void requestInitialized(ServletRequestEvent sre) {
sre.getServletRequest().setAttribute("Listener", "Listener");
log.info("监听器-方法开始");
ServletRequestListener.super.requestInitialized(sre);
}
@Override
public void requestDestroyed(ServletRequestEvent sre) {
log.info("监听器-方法结束");
ServletRequestListener.super.requestDestroyed(sre);
}
}
- 使用 @Bean+ServletListenerRegistrationBean注册
@Configuration
public class MyConfig {
final
MyListener myListener;
public MyConfig(MyListener myListener) {
this.myListener = myListener;
}
@Bean
public ServletListenerRegistrationBean<MyListener> listenerRegistrationBean() {
ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>();
registrationBean.setListener(myListener);
return registrationBean;
}
}
- 使用 @WebListener 注解
@WebListener
public class MyListener implements ServletRequestListener {
Logger log = LoggerFactory.getLogger(MyListener.class);
@Override
public void requestInitialized(ServletRequestEvent sre) {
sre.getServletRequest().setAttribute("Listener", "Listener");
log.info("监听器-方法开始");
ServletRequestListener.super.requestInitialized(sre);
}
@Override
public void requestDestroyed(ServletRequestEvent sre) {
log.info("监听器-方法结束");
ServletRequestListener.super.requestDestroyed(sre);
}
}
注意 使用 @WebListener 注解时，需要在 启动类添加 @ServletComponentScan 注解
@SpringBootApplication
@ServletComponentScan
public class SpringBootFilterListenerApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootFilterListenerApplication.class, args);
}
}
Listener 也可以在Listener 组件上使用 @Order 或者使用 ServletListenerRegistrationBean.setOrder() 方法设置优先级。
