Java ExecutorServic线程池异步实现流程

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author szy 
 * @version 创建时间：2018-5-20 上午10:25:06
 * 
 */
public class Testasync {

  /**
   * @param args
   */
  public static void main(String[] args) {
    // TODO Auto-generated method stub
    if(task0() == true){
      System.out.println("执行完毕，看异步结果");
    }
    
  }

  
  public static void task1(){
    System.out.println("task1 is start");
  }
  
  public static void task2(){
     ExecutorService executor = Executors.newFixedThreadPool(1);
     executor.submit(new Callable(){

      @Override
      public Object call() throws Exception {
        // TODO Auto-generated method stub
        
        //增加睡眠时间，便于查看结果
        /* try {
            Thread.sleep(10000);
          } catch (InterruptedException e) {
            e.printStackTrace();
          }*/
         
        //异步提交
        int sum = 0;
        for (int i = 0; i < 10000; i++) {
           sum += i;
        }
        System.out.println("task2执行数据的大量导入或者导出");
        System.out.println("task2="+sum);
        System.out.println("task2导入或者导出完成");
        return null;
      }
       
       
     });
    
  }
  
  public static void task3(){
    System.out.println("task3 is start");
    int j = 0;
    while(true) {
      if(j++ > 10) {
        break;
      }
      System.out.println("------------task3 end-----------");
    }
  }
  
  public static boolean task0(){
    task1();
    task2();
    task3();
    return true;
  }
}

task1 is start
task3 is start
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
------------task3 end-----------
task2执行数据的大量导入或者导出
执行完毕，看异步结果
task2=49995000
task2导入或者导出完成