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package concurrent;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* Created by IntelliJ IDEA.
*
* @author leizhimin 2008-11-25 14:28:59
*/
public class TestCachedThreadPool {
public static void main(String[] args) {
// ExecutorService executorService = Executors.newCachedThreadPool();
ExecutorService executorService = Executors.newFixedThreadPool(5);
// ExecutorService executorService = Executors.newSingleThreadExecutor();
for (int i = 0; i < 5; i++) {
executorService.execute(new TestRunnable());
System.out.println("************* a" + i + " *************");
}
executorService.shutdown();
}
}
class TestRunnable implements Runnable {
public void run() {
System.out.println(Thread.currentThread().getName() + "线程被调用了。");
while (true) {
try {
Thread.sleep(5000);
System.out.println(Thread.currentThread().getName());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
运行结果:
************* a0 *************
************* a1 *************
pool-1-thread-2线程被调用了。
************* a2 *************
pool-1-thread-3线程被调用了。
pool-1-thread-1线程被调用了。
************* a3 *************
************* a4 *************
pool-1-thread-4线程被调用了。
pool-1-thread-5线程被调用了。
pool-1-thread-2
pool-1-thread-1
pool-1-thread-3
pool-1-thread-5
pool-1-thread-4
pool-1-thread-2
pool-1-thread-1
pool-1-thread-3
pool-1-thread-5
pool-1-thread-4
......
public interface Callable<V>
返回结果并且可能抛出异常的任务。实现者定义了一个不带任何参数的叫做 call 的方法。
Runnable
,两者都是为那些其实例可能被另一个线程执行的类设计的。但是 Runnable 不会返回结果,并且无法抛出经过检查的异常。
Executors
类包含一些从其他普通形式转换成 Callable 类的实用方法。 import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.*;
/**
* Callable接口测试
*
* @author leizhimin 2008-11-26 9:20:13
*/
public class CallableDemo {
public static void main(String[] args) {
ExecutorService executorService = Executors.newCachedThreadPool();
List<Future<String>> resultList = new ArrayList<Future<String>>();
//创建10个任务并执行
for (int i = 0; i < 10; i++) {
//使用ExecutorService执行Callable类型的任务,并将结果保存在future变量中
Future<String> future = executorService.submit(new TaskWithResult(i));
//将任务执行结果存储到List中
resultList.add(future);
}
//遍历任务的结果
for (Future<String> fs : resultList) {
try {
System.out.println(fs.get()); //打印各个线程(任务)执行的结果
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
} finally {
//启动一次顺序关闭,执行以前提交的任务,但不接受新任务。如果已经关闭,则调用没有其他作用。
executorService.shutdown();
}
}
}
}
class TaskWithResult implements Callable<String> {
private int id;
public TaskWithResult(int id) {
this.id = id;
}
/**
* 任务的具体过程,一旦任务传给ExecutorService的submit方法,则该方法自动在一个线程上执行。
*
* @return
* @throws Exception
*/
public String call() throws Exception {
System.out.println("call()方法被自动调用,干活!!! " + Thread.currentThread().getName());
//一个模拟耗时的操作
for (int i = 999999; i > 0; i--) ;
return "call()方法被自动调用,任务的结果是:" + id + " " + Thread.currentThread().getName();
}
}
运行结果:
call()方法被自动调用,干活!!! pool-1-thread-1
call()方法被自动调用,干活!!! pool-1-thread-3
call()方法被自动调用,干活!!! pool-1-thread-4
call()方法被自动调用,干活!!! pool-1-thread-6
call()方法被自动调用,干活!!! pool-1-thread-2
call()方法被自动调用,干活!!! pool-1-thread-5
call()方法被自动调用,任务的结果是:0 pool-1-thread-1
call()方法被自动调用,任务的结果是:1 pool-1-thread-2
call()方法被自动调用,干活!!! pool-1-thread-2
call()方法被自动调用,干活!!! pool-1-thread-6
call()方法被自动调用,干活!!! pool-1-thread-4
call()方法被自动调用,任务的结果是:2 pool-1-thread-3
call()方法被自动调用,干活!!! pool-1-thread-3
call()方法被自动调用,任务的结果是:3 pool-1-thread-4
call()方法被自动调用,任务的结果是:4 pool-1-thread-5
call()方法被自动调用,任务的结果是:5 pool-1-thread-6
call()方法被自动调用,任务的结果是:6 pool-1-thread-2
call()方法被自动调用,任务的结果是:7 pool-1-thread-6
call()方法被自动调用,任务的结果是:8 pool-1-thread-4
call()方法被自动调用,任务的结果是:9 pool-1-thread-3
Process finished with exit code 0
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原文地址:http://www.cnblogs.com/winner-0715/p/5863020.html