学习多线程4---线程池的使用

ExecutorService 创建线程池，线程池可以定义线程的数量

future指线程执行后需要返回的结果，结果可以自己定义

callable相当于runnable

package com.condition;

import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

public class CallableAndFuture {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		ExecutorService threadPool =  Executors.newSingleThreadExecutor();
		Future<String> future =
			threadPool.submit(
				new Callable<String>() {
					public String call() throws Exception {
						Thread.sleep(2000);
						return "hello";
					};
				}
		);
		System.out.println("等待结果");
		try {
			System.out.println("拿到结果：" + future.get());
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
｝