繼承Thread()類完成多線程，一般需要4步：

（1）新建一個MyThread類繼承Thread類

（2）在MyThread類中重寫run()方法

（3）在主線程中創建線程對象 Thread t = new Thread();

（4）在主線程中啟動線程t.start()

上述過程，要分別在兩個類中實現。

下面的將展示在一個類中實現

 1 public class SleepWaitDemo {
 2     public static void main(String[] args) {
 3         final Object lock = new Object();
 
 4         // 創建A線程，並啟動
 5         new Thread(new Runnable() {
 6             public void run() {
 7                 System.out.println("thread A is waiting to  get lock");
 8                 synchronized (lock) {
 9                     try {
10                         System.out.println("thread A get lock");
 
11                         Thread.sleep(20);//sleep()僅釋放CPU但不釋放鎖
12                         System.out.println("thread A  do wait method");
13                         lock.wait(1000);//wait()釋放CPU和鎖
14                         System.out.println("thread A is done");
15                     } catch (InterruptedException e) {
 
16                         e.printStackTrace();
17                     }
18                 }
19             }
20         }).start();// 創建A線程並啟動完畢
21         
22         try {
23             Thread.sleep(10);//主線程sleep 10ms
24         } catch (InterruptedException e1) {
25             e1.printStackTrace();
26         }
27         
28         // 創建B線程，並啟動
29                 new Thread(new Runnable() {
30                     public void run() {
31                         System.out.println("thread B is waiting to get lock");
32                         synchronized (lock) {
33                             try {
34                                 System.out.println("thread B  get lock");
35                                 System.out.println("thread B is sleeping 10ms");
36                                 Thread.sleep(10);
37                                 System.out.println("thread B is done");
38                             } catch (InterruptedException e) {
39                                 e.printStackTrace();
40                             }
41                         }
42                     }
43                 }).start();// 創建B線程並啟動完畢
44     }
45 }

結果為：

thread A is waiting to get lock

thread B is waiting to get lock

thread A do wait method

thread B get lock

thread B is sleeping 10ms

thread B is done

thread A is done

第二個例子

 1 public class SleepWaitDemo {
 2     public static void main(String[] args) {
 3         final Object lock = new Object();
 4         // 創建A線程，並啟動
 5         new Thread(new Runnable() {
 6             public void run() {
 7                 System.out.println("thread A is waiting to  get lock");
 8                 synchronized (lock) {
 9                     try {
10                         System.out.println("thread A get lock");
11                         Thread.sleep(20);//sleep()僅釋放CPU但不釋放鎖
12                         System.out.println("thread A  do wait method");
13                         Thread.sleep(1000);
14                         System.out.println("thread A is done");
15                     } catch (InterruptedException e) {
16                         e.printStackTrace();
17                     }
18                 }
19             }
20         }).start();// 創建A線程並啟動完畢
21         
22         try {
23             Thread.sleep(10);//主線程sleep 10ms
24         } catch (InterruptedException e1) {
25             e1.printStackTrace();
26         }
27         
28         // 創建B線程，並啟動
29                 new Thread(new Runnable() {
30                     public void run() {
31                         System.out.println("thread B is waiting to get lock");
32                         synchronized (lock) {
33                             try {
34                                 System.out.println("thread B  get lock");
35                                 System.out.println("thread B is sleeping 10ms");
36                                 lock.wait(10);//wait()釋放CPU和鎖
37                                 System.out.println("thread B is done");
38                             } catch (InterruptedException e) {
39                                 e.printStackTrace();
40                             }
41                         }
42                     }
43                 }).start();// 創建B線程並啟動完畢
44     }
45 }

結果：

thread A is waiting to get lock

thread A get lock

thread B is waiting to get lock

thread A do wait method

thread A is done

thread B get lock

thread B is sleeping 10ms

thread B is done

在一個類中寫完多線程（sleep 方法和wait 方法的區別）