springboot异步执行

1. 创建springboot项目
2. 调用多线程controller

   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.stereotype.Controller;
   import org.springframework.web.bind.annotation.GetMapping;
   import org.springframework.web.bind.annotation.ResponseBody;
   
   @Controller
   public class AsyncController {
   
   	@Autowired
   	private User2Service user2Service;
   	
   	@GetMapping("/async")
   	@ResponseBody
   	public Object async(){
   		System.out.println("步骤------1");
   		user2Service.index();
   		System.out.println("步骤------2");
   		return "success";
   	}
   }

3. 创建执行多线程方法

   import org.springframework.scheduling.annotation.Async;
   import org.springframework.stereotype.Component;
   
   @Component
   public class User2Service {
   
   	@Async  // 多线程执行
   	public void index(){
   		System.out.println("步骤------3");
   		for (int i = 0; i < 10; i++) {
   			try {
   				Thread.sleep(1000);
   			} catch (InterruptedException e) {
   				// TODO Auto-generated catch block
   				e.printStackTrace();
   			}
   			System.out.println(+i);
   		}
   		System.out.println("步骤------4");
   	}
   	
   }

4. 开启多线程注解

   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.cache.annotation.EnableCaching;
   import org.springframework.scheduling.annotation.EnableAsync;
   import org.springframework.scheduling.annotation.EnableScheduling;
   
   @SpringBootApplication
   @EnableCaching // 开启缓存注解
   //@EnableScheduling // 开启定时任务
   @EnableAsync  // 开启异步注解
   public class App {
   
   	public static void main(String[] args) {
   		// TODO Auto-generated method stub
   		SpringApplication.run(App.class, args);
   	}
   
   }

5. 启动

6. 打印的执行步骤是1-2-3-4    其主线程的执行优先级高，

7. 去掉异步注解在执行的步骤是1-3-4-2    都是主线程在跑