import java.util.Map;

import java.util.concurrent.ConcurrentHashMap;

import org.junit.Assert;

import org.junit.Test;

/**

 * 线程的两种实现方法

 */

public class ThreadImplementTest {

    private Map<Integer, Long> map = new ConcurrentHashMap<>();

    class MethodOne extends Thread {

        private int count = 0;

        @Override

        public void run() {

            map.put(++count, this.getId());

        }

    }

    class MethodTwo implements Runnable {

        private int count = 31;

        @Override

        public void run() {

            map.put(++count, Thread.currentThread().getId());

        }

    }

    @Test

    public void testThread(){

        //方法一：继承Thread

        MethodOne extendsThread = new MethodOne();

        extendsThread.start();

        //方法二：实现Runnable接口

        MethodTwo implementsRunnable = new MethodTwo();

        new Thread(implementsRunnable).start();

        System.out.println("ddd");

    }

    @Test

    public void testTwoRuns() throws InterruptedException{

        /*

         * 注意：一下两种方法启动方式截然不同

         */

        Thread tmp;

        MethodOne extendsThread = new MethodOne();

        for (int i = 0; i < 3; i++) {//只有一个线程

            tmp = new Thread(extendsThread);

            tmp.start();

            tmp.join();

        }

        Assert.assertTrue(map.containsKey(3));

        Assert.assertTrue(map.containsKey(2));

        Assert.assertTrue(map.containsKey(1));

        map.clear();// 清空缓存

        for (int i = 0; i < 3; i++) {// 三个不同线程

            tmp = new MethodOne();

            tmp.start();

            tmp.join();

        }

        Assert.assertEquals(1, map.size());

        Assert.assertTrue(map.containsKey(1));

    }

}