背景需求：
由于项目启动时，需要自动加载初始化一些数据，这时候可以使用监听类
一、定义监听类，实现ApplicationListener接口：
package com.cobra.webdemo.listener;
import org.springframework.boot.context.event.ApplicationEnvironmentPreparedEvent;
import org.springframework.boot.context.event.ApplicationPreparedEvent;
import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextClosedEvent;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.context.event.ContextStartedEvent;
import org.springframework.context.event.ContextStoppedEvent;
/**
* @Author: Baron
* @Description:
* @Date: Created in 2019/3/2317:16
*/
public class ApplicationEventListener implements ApplicationListener {
@Override
public void onApplicationEvent(ApplicationEvent event) {
if (event instanceof ApplicationEnvironmentPreparedEvent){
System.out.println("环境初始化！！！");
} else if (event instanceof ApplicationPreparedEvent){
System.out.println("初始化完成！！！");
} else if (event instanceof ContextRefreshedEvent) {
System.out.println("应用刷新！！");
} else if (event instanceof ApplicationReadyEvent) {
System.out.println("项目启动完成！！");
} else if (event instanceof ContextStartedEvent) {
System.out.println("应用启动！！");
} else if (event instanceof ContextStoppedEvent) {
System.out.println("项目停止！！");
} else if (event instanceof ContextClosedEvent) {
System.out.println("应用关闭！！");
}
}
}
二、监听类注入容器，添加监听：
方式一，在application.yml配置文件配置：
#配置启动监听
context:
listener:
classes: com.cobra.webdemo.listener.ApplicationEventListener方式二，在启动类main函数添加监听：
package com.cobra.webdemo;
import com.cobra.webdemo.listener.ApplicationEventListener;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class WebdemoApplication {
public static void main(String[] args) {
SpringApplication app = new SpringApplication(WebdemoApplication.class);
app.addListeners(new ApplicationEventListener());
app.run(args);
}
}测试：
方式三，直接用@Component注入bean，这种方法只能监听刷新和启动完成：
package com.cobra.webdemo.listener;
import org.springframework.boot.context.event.ApplicationEnvironmentPreparedEvent;
import org.springframework.boot.context.event.ApplicationPreparedEvent;
import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextClosedEvent;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.context.event.ContextStartedEvent;
import org.springframework.context.event.ContextStoppedEvent;
import org.springframework.stereotype.Component;
/**
* @Author: Baron
* @Description:
* @Date: Created in 2019/3/2317:16
*/
@Component
public class ApplicationEventListener implements ApplicationListener {
@Override
public void onApplicationEvent(ApplicationEvent event) {
if (event instanceof ApplicationEnvironmentPreparedEvent){
System.out.println("环境初始化！！！");
} else if (event instanceof ApplicationPreparedEvent){
System.out.println("初始化完成！！！");
} else if (event instanceof ContextRefreshedEvent) {
System.out.println("应用刷新！！");
} else if (event instanceof ApplicationReadyEvent) {
System.out.println("项目启动完成！！");
} else if (event instanceof ContextStartedEvent) {
System.out.println("应用启动！！");
} else if (event instanceof ContextStoppedEvent) {
System.out.println("项目停止！！");
} else if (event instanceof ContextClosedEvent) {
System.out.println("应用关闭！！");
}
}
}
测试：
