代碼詳解の使用CountDownLatch解決面試問題：T1和T2線程執行計算，T3線程計算結果的統計

package com.sdmjhca.springBootDemo.synchronizedtest;

import java.util.concurrent.CountDownLatch;

/**
 * 例子：T1和T2線程執行計算，T3線程進行T1和T2結果的統計
 * 思路定義一個“鎖計數器”爲2的線程併發類，T3通過await方法進行鎖等待，T1執行完成後計數器-1，T2完成後計數器-1；
 * 當計數器爲0後，T3開始執行統計方法，得到最終計算結果
 * @author JHMI on 2017/8/18.
 */
public class SynchronizedMain {
    private static CountDownLatch start = new CountDownLatch(1);
    private static CountDownLatch end = new CountDownLatch(2);
    private static int i = 1;

    private static int j = 1;
    public static void main(String args[]) throws InterruptedException {
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    start.await();
                    System.out.println("T1開始執行");

                    //SynchronizedTest.staticIn.method1();
                    i++;
                    //Thread.sleep(1000);
                    end.countDown();
                    System.out.println("T1計算結束");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

            }
        });
        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    start.await();
                    System.out.println("T2開始執行");

                   // SynchronizedTest.staticIn.method2();

                    j++;
                    //Thread.sleep(1000);
                    end.countDown();
                    System.out.println("T2執行結束");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

            }
        });
        Thread t3 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {

                    start.await();
                    System.out.println("T3開始執行，進入等待狀態");
                    end.await();
                    System.out.println("獲得鎖 開始執行T3");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                //Thread.sleep(1000);

                int c = i+j;
                System.out.println("統計結果="+c);
                System.out.println("T3執行結束");

            }
        });
        t1.start();
        t2.start();
        t3.start();
        start.countDown();
       /* i = i+j;
        System.out.println("i="+i);*/
    }
}