java多线程的三种创建方式

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java多线程的三种创建方式

第一种方式，继承Thread类，重写run方法，这里我模拟了一个买票的系统，四个窗口同时开始卖票

/**
 * 第一种方式，继承Thread类，重写run方法
 * 
 * @author admin
 *
 */
public class MyThread extends Thread {
	private static int num = 100; // 共享变量(基本数据类型的数据)，不能当对象锁---因为它不是对象
	private static Object obj = new Object();// 可以新建一个与基本数据类型的共享变量平行的对象，来替代它当作锁
	private String name = null;

	public MyThread(String name) {
		this.name = name;
	}

	@Override
	public void run() {
		while (true) {
			synchronized (obj) {// ※静态变量的对象锁是不能用this来代替的
				if (num > 0) {
					System.out.println(name + ":" + num);
					num--;//卖出去了一张，减去一张
					try {
						Thread.sleep(50);//睡眠0.02秒
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				} else {
					break;
				}
			}
		}
	}
}

第一种方法测试类

/**
 * 测试第一种方式
 * 
 * @author admin
 *
 */
public class MyThreadTest {

	public static void main(String[] args) {
		// 开四个窗口(new线程)，让它们都开始卖票(启动线程)
		Thread t1 = new MyThread("窗口1");
		Thread t2 = new MyThread("窗口2");
		Thread t3 = new MyThread("窗口3");
		Thread t4 = new MyThread("窗口4");
		t1.start();
		t2.start();
		t3.start();
		t4.start();
	}
}

控制台输出

窗口1:100
窗口1:99
窗口1:98
窗口1:97
窗口1:96
窗口1:95
窗口1:94
窗口1:93
窗口1:92
窗口1:91
窗口1:90
窗口1:89
窗口1:88
窗口1:87
窗口1:86
窗口1:85
窗口1:84
窗口1:83
窗口1:82
窗口1:81
窗口1:80
窗口1:79
窗口1:78
窗口1:77
窗口1:76
窗口1:75
窗口1:74
窗口1:73
窗口1:72
窗口1:71
窗口1:70
窗口1:69
窗口1:68
窗口1:67
窗口1:66
窗口1:65
窗口1:64
窗口1:63
窗口1:62
窗口1:61
窗口1:60
窗口1:59
窗口1:58
窗口1:57
窗口1:56
窗口1:55
窗口1:54
窗口1:53
窗口1:52
窗口1:51
窗口1:50
窗口1:49
窗口1:48
窗口1:47
窗口1:46
窗口1:45
窗口1:44
窗口1:43
窗口1:42
窗口4:41
窗口4:40
窗口4:39
窗口4:38
窗口4:37
窗口4:36
窗口4:35
窗口4:34
窗口4:33
窗口4:32
窗口4:31
窗口4:30
窗口4:29
窗口4:28
窗口4:27
窗口4:26
窗口4:25
窗口2:24
窗口2:23
窗口2:22
窗口2:21
窗口2:20
窗口2:19
窗口2:18
窗口2:17
窗口2:16
窗口2:15
窗口2:14
窗口2:13
窗口2:12
窗口2:11
窗口2:10
窗口2:9
窗口2:8
窗口2:7
窗口2:6
窗口2:5
窗口2:4
窗口2:3
窗口2:2
窗口2:1

第二种方式，实现runnable接口，重写run方法。这种方法跟第一种类似，因为Thread类实现的就是runnable接口

/**
 * 第二种方式，实现runnable接口，重写run方法
 * 
 * @author admin
 *
 */
public class MyRunnable implements Runnable {
	private static int num = 100;// 共享变量(基本数据类型的数据)，不能当对象锁---因为它不是对象
	private static Object obj = new Object();// 可以新建一个与基本数据类型的共享变量平行的对象，来替代它当作锁

	@Override
	public void run() {
		while (num > 0) {
			synchronized (obj) {
				if (num > 0) {
					System.out.println(Thread.currentThread().getName() + "---" + num);
					num--;//卖出去了一张，减去一张
					try {
						Thread.sleep(50);//睡眠0.05秒
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
			}
		}
	}

}

第二种方式测试

/**
 * 测试第二种方式
 * 
 * @author admin
 *
 */
public class MyRunnableTest {
	public static void main(String[] args) {
		MyRunnable myRunnable = new MyRunnable();//创建runnable对象
		Thread thread1 = new Thread(myRunnable);//runnable对象作为Thread对象的target创建新的线程
		Thread thread2 = new Thread(myRunnable);
		Thread thread3 = new Thread(myRunnable);
		thread1.start();
		thread2.start();
		thread3.start();
	}
}

控制台

Thread-0---100
Thread-0---99
Thread-0---98
Thread-0---97
Thread-0---96
Thread-0---95
Thread-0---94
Thread-0---93
Thread-0---92
Thread-0---91
Thread-0---90
Thread-0---89
Thread-0---88
Thread-0---87
Thread-1---86
Thread-1---85
Thread-1---84
Thread-1---83
Thread-1---82
Thread-1---81
Thread-1---80
Thread-1---79
Thread-1---78
Thread-1---77
Thread-1---76
Thread-1---75
Thread-1---74
Thread-1---73
Thread-1---72
Thread-1---71
Thread-1---70
Thread-1---69
Thread-1---68
Thread-1---67
Thread-2---66
Thread-2---65
Thread-2---64
Thread-2---63
Thread-2---62
Thread-2---61
Thread-2---60
Thread-2---59
Thread-2---58
Thread-2---57
Thread-2---56
Thread-2---55
Thread-2---54
Thread-2---53
Thread-2---52
Thread-2---51
Thread-2---50
Thread-2---49
Thread-2---48
Thread-2---47
Thread-2---46
Thread-2---45
Thread-2---44
Thread-2---43
Thread-2---42
Thread-2---41
Thread-2---40
Thread-2---39
Thread-2---38
Thread-2---37
Thread-2---36
Thread-2---35
Thread-2---34
Thread-2---33
Thread-2---32
Thread-2---31
Thread-2---30
Thread-2---29
Thread-2---28
Thread-1---27
Thread-1---26
Thread-1---25
Thread-1---24
Thread-1---23
Thread-1---22
Thread-1---21
Thread-1---20
Thread-1---19
Thread-1---18
Thread-1---17
Thread-1---16
Thread-1---15
Thread-1---14
Thread-1---13
Thread-1---12
Thread-1---11
Thread-1---10
Thread-1---9
Thread-1---8
Thread-1---7
Thread-1---6
Thread-1---5
Thread-1---4
Thread-1---3
Thread-1---2
Thread-1---1

第三种方式，实现callable接口，重写call方法，这种方法可以获取线程的返回值

/**
 * 第三种方式，实现callable接口，重写call方法
 * 
 * @author admin
 *
 */
public class MyCallable implements Callable<Integer> {
	private static int i = 0;

	@Override
	public Integer call() throws Exception {
		int sum = 0;
		for (; i < 100; i++) {
			System.out.println(Thread.currentThread().getName() + " " + i);
			sum += i;
		}
		return sum;
	}

}

第三种方式测试

/**
 * 测试第三种方式
 * 
 * @author admin
 *
 */
public class MyCallableTest {
	public static void main(String[] args) {
		Callable<Integer> myCallable = new MyCallable(); // 创建MyCallable对象
		FutureTask<Integer> ft = new FutureTask<Integer>(myCallable); // 使用FutureTask来包装MyCallable对象
		Thread thread = new Thread(ft); // FutureTask对象作为Thread对象的target创建新的线程
		thread.start(); // 线程进入到就绪状态
		try {
			int sum = ft.get(); // 用FutureTask对象的get()方法取得新创建的新线程中的call()方法返回的结果
			System.out.println("sum = " + sum);
		} catch (InterruptedException e) {
			e.printStackTrace();
		} catch (ExecutionException e) {
			e.printStackTrace();
		}

	}
}

控制台

Thread-0 0
Thread-0 1
Thread-0 2
Thread-0 3
Thread-0 4
Thread-0 5
Thread-0 6
Thread-0 7
Thread-0 8
Thread-0 9
Thread-0 10
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Thread-0 99
sum = 4950

个人写的小Demo，如有不足还请各路大神指教