概述：

main方法：主線程想做兩件事=兩個(gè)任務(wù)：報(bào)名考試和買(mǎi)書(shū)
但是用一個(gè)Callable任務(wù)發(fā)起一個(gè)線程來(lái)做買(mǎi)書(shū)的任務(wù)-耗時(shí)7秒轴捎；
主線程自己完成報(bào)名考試的任務(wù)-耗時(shí)10秒悄谐；

package com.niewj.concurrent;

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;

/**
 * Future和Callable例1
 * @author weijun.nie
 *
 */
public class ES_TPE_Test {

    public static void main(String[] args) throws InterruptedException, ExecutionException {
        ExecutorService executerService = Executors.newSingleThreadExecutor();

        // 主線程要做兩件事：1.買(mǎi)書(shū); 2.報(bào)名考試
        long start = System.currentTimeMillis();

        // 1. 第一件事：買(mǎi)書(shū)
        Future<Book> future = executerService.submit(new BuyBookTask()); // 定義了一個(gè)任務(wù)：買(mǎi)書(shū)陵叽，需要一定的時(shí)間
        executerService.shutdown();
        
        
        // 2. 第一件事：報(bào)名考試 報(bào)名考試花費(fèi)10秒
        for (int i = 1; i <= 10; i++) {
            Thread.sleep(1000);
            System.out.println("==== ==== 等報(bào)名排隊(duì)等了[ " + i + " ]天了 ==== ==== ");
        }
        
        Book book = future.get();
        System.out.println("考試報(bào)上名了; 書(shū)也買(mǎi)到了： " + book);
        long end = System.currentTimeMillis();
        System.out.println("總耗時(shí)秒數(shù)： " + (end - start) / 1000);

    }

}

/**
 * 購(gòu)買(mǎi)書(shū)籍任務(wù)-需要耗費(fèi)一定時(shí)間：假定買(mǎi)書(shū)需要等7天(一秒模擬一天)
 * 
 * @author weijun.nie
 *
 */
class BuyBookTask implements Callable<Book> {

    final int restockDays = 7; // 等進(jìn)貨時(shí)間

    @Override
    public Book call() throws Exception {
        for (int i = 1; i <= restockDays; i++) {
            Thread.sleep(1000);
            System.out.println("等書(shū)等了[ " + i + " ]天了。好啰。。数苫。。柱查。");
        }

        return new Book("稀缺書(shū)套裝", 120.5);
    }

}

class Book {
    private String name;
    private Double price;

    public Book(String name, Double price) {
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    @Override
    public String toString() {
        if (this.name == null && this.price == null) {
            return "沒(méi)有書(shū)！";
        } else {
            return name + " 這本書(shū) " + price + "元錢(qián)";
        }
    }
}