(原)测试 Java中Synchronized锁定对象的用法
今天再android_serial_port中看到了关键字 synchronized;因为刚好在学java和android，所以就查了一下它的用法：
于是把代码中的一小段代码拿了出来，做了一下修改，测试了下，结果出现的情况：
1 public class syncThreadDemo { 2 3 public static void main(String[] args) { 4 // TODO Auto-generated method stub 5 /*测试1*/ 6 // Account account = new Account("zhang san", 10000.0f); 7 // AccountOperator accountOperator = new AccountOperator(account); 8 // 9 // final int THREAD_NUM = 5; 10 // Thread threads[] = new Thread[THREAD_NUM]; 11 // for (int i = 0; i < THREAD_NUM; i ++) { 12 // threads[i] = new Thread(accountOperator, "Thread" + i); 13 // threads[i].start(); 14 // } 15 16 /*测试2*/ 17 18 Thread thread1=new Thread(new syncThreadDemo().new SendingThread("send1"),"thread1"); 19 thread1.start(); 20 Thread thread2=new Thread(new syncThreadDemo().new ReceiveThread("recv1"),"thread2"); 21 thread2.start(); 22 23 } 24 /*创建一个内部类来测试synchronized锁定一个对象*/ 25 static Object mByteReceivedBackSemaphore = new Object(); 26 27 private class SendingThread implements Runnable{ 28 private int i=0; 29 private String name; 30 //创建一个构造函数 31 public SendingThread(String strName) { 32 // TODO Auto-generated constructor stub 33 this.name=strName; 34 } 35 36 @Override 37 public void run(){ 38 while (i<10) { 39 synchronized (mByteReceivedBackSemaphore) { 40 try { 41 // Wait for 100ms before sending next byte, or as soon as 42 // the sent byte has been read back. 43 System.out.println(Thread.currentThread().getName()+": wait"); 44 mByteReceivedBackSemaphore.wait(100); 45 i++; 46 System.out.println(Thread.currentThread().getName()+":"+i); 47 } 48 catch (Exception e) { 49 // TODO: handle exception 50 } 51 } 52 } 53 } 54 } 55 56 private class ReceiveThread implements Runnable{ 57 private int j=0; 58 private String name; 59 60 public ReceiveThread(String strName) { 61 // TODO Auto-generated constructor stub 62 this.name=strName; 63 } 64 65 @Override 66 public void run(){ 67 while(j<10){ 68 synchronized(mByteReceivedBackSemaphore){ 69 System.out.println(Thread.currentThread().getName()+": notify"); 70 mByteReceivedBackSemaphore.notify(); 71 j++; 72 System.out.println(Thread.currentThread().getName()+":"+j); 73 } 74 } 75 } 76 } 77 }
测试结果：
thread1: wait thread2: notify thread2:1 thread2: notify thread2:2 thread2: notify thread2:3 thread2: notify thread2:4 thread2: notify thread2:5 thread2: notify thread2:6 thread2: notify thread2:7 thread2: notify thread2:8 thread2: notify thread2:9 thread2: notify thread2:10 thread1:1 thread1: wait thread1:2 thread1: wait thread1:3 thread1: wait thread1:4 thread1: wait thread1:5 thread1: wait thread1:6 thread1: wait thread1:7 thread1: wait thread1:8 thread1: wait thread1:9 thread1: wait thread1:10
