三十三、Spring Boot实现异步调用

                          Spring Boot实现异步调用

开启异步调用：

package com.yang;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableScheduling//开启定时任务
@EnableAsync//开启异步调用
public class DubboSpringBootApplication {

    public static void main(String[] args) {
        SpringApplication.run(DubboSpringBootApplication.class, args);
    }
}

声明可被异步调用的方法：

package com.yang.task;

import java.util.concurrent.Future;

import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;
import org.springframework.stereotype.Component;

@Component
public class AsyncTask {
    //@Async所修饰的函数不要定义为static类型，这样异步调用不会生效
    //异步回调不返回数据
    @Async
    public void dealNoReturnTask(){

        System.out.println("Thread {} deal No Return Task start"
                            + "    "
                            +Thread.currentThread().getName());
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("Thread {} deal No Return Task end at {}"+"    "
                            +Thread.currentThread().getName()+"    "
                            +System.currentTimeMillis());
     }



    //异步回调返回数据
    @Async
    public Future<String> dealHaveReturnTask() {
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }       
        return new AsyncResult<String>("异步回调返回数据！");
    }
}

测试：

//不带返回值的异步回调
 asyncTask.dealNoReturnTask();
  try {
        System.out.println("begin to deal other Task!");
    Thread.sleep(10000);
  } catch (InterruptedException e) {
   e.printStackTrace();
  }


//带返回值的异步回调
//用future.get()来获取异步任务的返回结果
Future<String> future = asyncTask.dealHaveReturnTask();
System.out.println("begin to deal other Task!");
 while (true) {
  if(future.isCancelled()){
      System.out.println("deal async task is Cancelled");
      break;
  }
  if (future.isDone() ) {
      System.out.println("deal async task is Done");
      System.out.println("return result is " + future.get());
      break;
  }
  System.out.println("wait async task to end ...");
  Thread.sleep(1000);
}