定义事件
@Getter
public class TestEvent extends ApplicationEvent {
private String msg;
public TestEvent(Object source, String msg) {
super(source);
this.msg = msg;
}
}
定义事件监听(注解方式)
@Component
public class TestListen {
@EventListener
public void testListen(TestEvent event) {
System.out.println(event.getMsg());
}
}
注意：@Component 注解
发布事件
@Autowired
private ApplicationContext publiser;
@GetMapping("test-listen")
public void testListen() {
for (int i = 0; i < 10; i++) {
System.out.println("i = " + i);
}
publiser.publishEvent(new TestEvent(this, "测试事件监听"));
for (int j = 0; j < 10; j++) {
System.out.println("j = " + j);
}
}
测试时执行顺序：
异步监听
监听加上@Async注解
@Component
public class TestListen {
@EventListener
@Async
public void testListen(TestEvent event) {
for (int i = 0; i < 10; i++) {
System.out.println("event = [" + event.getMsg() + "]");
}
}
}
测试时执行顺序：
代码： async
springboot进行事件监听有四种方式：
1.手工向ApplicationContext中添加监听器
2.将监听器装载入spring容器
3.在application.properties中配置监听器
4.通过@EventListener注解实现事件监听
讲到事件监听，这里我们说下自定义事件和自定义监听器类的实现方式：
下面讲下4种事件监听的具体实现
方式1.
首先创建MyListener1类
public class MyListener1 implements ApplicationListener<MyEvent>
{
Logger logger = Logger.getLogger(MyListener1.class);
public void onApplicationEvent(MyEvent event)
{
logger.info(String.format("%s监听到事件源：%s.", MyListener1.class.getName(), event.getSource()));
}
}
然后在springboot应用启动类中获取ConfigurableApplicationContext上下文，装载监听
@SpringBootApplication
public class LisenterApplication
{
public static void main(String[] args)
{
ConfigurableApplicationContext context = SpringApplication.run(LisenterApplication.class, args);
//装载监听
context.addApplicationListener(new MyListener1());
}
}
方式2.
创建MyListener2类，并使用@Component注解将该类装载入spring容器中
@Component
public class MyListener2 implements ApplicationListener<MyEvent>
{
Logger logger = Logger.getLogger(MyListener2.class);
public void onApplicationEvent(MyEvent event)
{
logger.info(String.format("%s监听到事件源：%s.", MyListener2.class.getName(), event.getSource()));
}
}
方式3.
首先创建MyListener3类
public class MyListener3 implements ApplicationListener<MyEvent>
{
Logger logger = Logger.getLogger(MyListener3.class);
public void onApplicationEvent(MyEvent event)
{
logger.info(String.format("%s监听到事件源：%s.", MyListener3.class.getName(), event.getSource()));
}
}
然后在application.properties中配置监听
context.listener.classes=com.listener.MyListener3
方式4.
创建MyListener4类，该类无需实现ApplicationListener接口，使用@EventListener装饰具体方法
@Component
public class MyListener4
{
Logger logger = Logger.getLogger(MyListener4.class);
@EventListener
public void listener(MyEvent event)
{
logger.info(String.format("%s监听到事件源：%s.", MyListener4.class.getName(), event.getSource()));
}
}
自定义事件代码如下：
@SuppressWarnings("serial")
public class MyEvent extends ApplicationEvent
{
public MyEvent(Object source)
{
super(source);
}
}
进行测试(在启动类中加入发布事件的逻辑)：
@SpringBootApplication
public class LisenterApplication
{
public static void main(String[] args)
{
ConfigurableApplicationContext context = SpringApplication.run(LisenterApplication.class, args);
//装载事件
context.addApplicationListener(new MyListener1());
//发布事件
context.publishEvent(new MyEvent("测试事件."));
}
}
启动后，日志打印如下：
2018-06-15 10:51:20.198 INFO 4628 --- [ main] com.listener.MyListener3 : com.listener.MyListener3监听到事件源：测试事件..
2018-06-15 10:51:20.198 INFO 4628 --- [ main] com.listener.MyListener4 : com.listener.MyListener4监听到事件源：测试事件..
2018-06-15 10:51:20.199 INFO 4628 --- [ main] com.listener.MyListener2 : com.listener.MyListener2监听到事件源：测试事件..
2018-06-15 10:51:20.199 INFO 4628 --- [ main] com.listener.MyListener1 : com.listener.MyListener1监
听到事件源：测试事件..
由日志打印可以看出，SpringBoot四种事件的实现方式监听是有序的
完整的代码路径：https://github.com/ingorewho/springboot-develope/tree/master/springboot-listener
