ExecutorService invokeAll 实例（转）

10个班级，每个班级20名学生，在指定的时间内查询每个班级学生的集合。

Java代码


package cn.com.ld.study.thread;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.concurrent.Callable;

import java.util.concurrent.ExecutionException;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

import java.util.concurrent.TimeUnit;

public class FutureTest {

//缓存操作数据集

private static final Map<Integer, List<Student>> sutdenMap = new HashMap<Integer, List<Student>>();

//初始化操作数据

static {

List<Student> stuList = null;

Student stu;

for (int i = 0; i < 10; i++) {

stuList = new ArrayList<Student>();

for (int j = 0; j < 2; j++) {

stu = new Student(j, "zld_" + i + "." + j, i);

stuList.add(stu);

}

sutdenMap.put(i, stuList);

}

}

public static class Student {

private int id;

private String name;

private int classID;

public Student(int id, String name, int classID) {

this.id = id;

this.name = name;

this.classID = classID;

}

public String toString() {

return Student.class.getName() + "(id:" + this.id + ",name:"

+ this.name + ")";

}

}

/**

* @filename: SearchTask

* @description: 查询任务

* @author lida

* @date 2013-4-1 下午3:02:29

*/

public static class SearchTask implements Callable<List<Student>> {

public final int classID;

public long sleepTime;

/**

* <p>Title: </p>

* <p>Description: </p>

* @param classID 班级编号

* @param sleepTime 模拟操作所用的时间数（毫秒）

*/

SearchTask(int classID, long sleepTime) {

this.classID = classID;

this.sleepTime = sleepTime;

}

@Override

public List<Student> call() throws Exception {

//模拟操作所用的时间数（毫秒）

Thread.sleep(sleepTime);

List<Student> stuList = sutdenMap.get(classID);

return stuList;

}

}

public static void main(String[] args) {

FutureTest ft = new FutureTest();

ExecutorService exec = Executors.newCachedThreadPool();

List<SearchTask> searchTasks = new ArrayList<SearchTask>();

SearchTask st;

for (int i = 0; i < 10; i++) {

st = new SearchTask(i, 2001);//指定2001 毫米为最大执行时间

searchTasks.add(st);

}

try {

//要求认为在2000毫秒内返回结果，否则取消执行。

List<Future<List<Student>>> futures = exec.invokeAll(searchTasks,

2000, TimeUnit.MILLISECONDS);//invokeAll 第一个参数是任务列表；第二个参数是过期时间；第三个是过期时间单位

for (Future<List<Student>> future : futures) {

List<Student> students = future.get();

for (Student student : students) {

System.out.println(student.toString());

}

}

exec.shutdown();

} catch (InterruptedException e) {

e.printStackTrace();

Thread.interrupted();

} catch (ExecutionException e) {

e.printStackTrace();

}

}

}
http://zld406504302.iteye.com/blog/1840091