启动加上@EnableAsync ,需要执行异步方法上加入@Async。
在方法上加上@Async之后 底层使用多线程技术。
先关代码：
package com.yiyang.myfirstspringdemo.controller; import com.yiyang.myfirstspringdemo.service.HelloService; import lombok.extern.slf4j.Slf4j; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import javax.annotation.Resource; @RestController @Slf4j public class HelloController { @Resource private HelloService helloService; @GetMapping("/helloAsync") public String helloAsync() { log.info("1"); helloService.addHello(); log.info("4"); return "hello world ==== async"; } } package com.yiyang.myfirstspringdemo.service; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Service; import javax.annotation.Resource; /** * @Author 刘翊扬 * @Date 2020/10/3 3:14 下午 * @Version 1.0 */ @Service @Slf4j public class HelloService { public void addHello() { log.info("2"); try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } log.info("3"); } }不使用异步处理。
正常输出的顺序：1 2 3 4
在addHello()方法上面加上@Async
同时，启动类上开启异步调用
package com.yiyang.myfirstspringdemo; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.scheduling.annotation.Async; import org.springframework.scheduling.annotation.EnableAsync; @SpringBootApplication(scanBasePackages = {"com.yiyang.myfirstspringdemo"}) //@SpringBootApplication @EnableAsync // 开启异步调用 public class MyFirstSpringDemoApplication { public static void main(String[] args) { SpringApplication.run(MyFirstSpringDemoApplication.class, args); } }再次访问，结果是：1 4 2 3
2020-10-03 15:52:52,660 INFO HelloController:24 - 1 2020-10-03 15:52:52,666 INFO HelloController:26 - 4 2020-10-03 15:52:52,675 INFO HelloService:23 - 2 2020-10-03 15:52:52,675 INFO LogAspect:51 - RESPONSE : hello world ==== async 2020-10-03 15:52:54,681 INFO HelloService:30 - 3注意：在同一个类中，一个方法调用另外一个有注解（比如@Async，@Transational）的方法，注解会失效
例如：
改造HelloService
访问结果是：1 2 3 4
2020-10-03 15:55:51,449 INFO HelloController:24 - 1 2020-10-03 15:55:51,585 INFO HelloService:17 - 2 2020-10-03 15:55:53,595 INFO HelloService:29 - 发送消息!!!!! 2020-10-03 15:55:53,596 INFO HelloService:19 - 3 2020-10-03 15:55:53,598 INFO HelloController:26 - 4 2020-10-03 15:55:53,599 INFO LogAspect:51 - RESPONSE : hello world ==== async解决办法。。。。。。
讲sendMessage()方法放到别的类里面。
新建SendMessageService类
package com.yiyang.myfirstspringdemo.service; import lombok.extern.slf4j.Slf4j; import org.springframework.scheduling.annotation.Async; import org.springframework.stereotype.Service; /** * @Author 刘翊扬 * @Date 2020/10/3 3:37 下午 * @Version 1.0 */ @Service @Slf4j public class SendMessageService { @Async public void sendMessage() { try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } log.info("发送消息!!!!!"); log.info("5"); } }修改HelloService的内容
package com.yiyang.myfirstspringdemo.service; import lombok.extern.slf4j.Slf4j; import org.springframework.scheduling.annotation.Async; import org.springframework.stereotype.Service; import javax.annotation.Resource; /** * @Author 刘翊扬 * @Date 2020/10/3 3:14 下午 * @Version 1.0 */ @Service @Slf4j public class HelloService { @Resource private SendMessageService sendMessage; public void addHello() { log.info("2"); sendMessage.sendMessage(); log.info("3"); } }访问结果是：1 2 3 4 5
2020-10-03 16:00:30,870 INFO HelloController:24 - 1 2020-10-03 16:00:30,871 INFO HelloService:22 - 2 2020-10-03 16:00:30,875 INFO HelloService:24 - 3 2020-10-03 16:00:30,891 INFO HelloController:26 - 4 2020-10-03 16:00:30,901 INFO LogAspect:51 - RESPONSE : hello world ==== async 2020-10-03 16:00:32,889 INFO SendMessageService:23 - 发送消息!!!!! 2020-10-03 16:00:32,890 INFO SendMessageService:24 - 5 那么为什么，在同一类中一个方法调用另外一个有注解（比如@Async，@Transational）的方法，注解会失效呢？？？？看这个博客：https://blog.csdn.net/clementad/article/details/47339519