Java多线程:线程同步——实验3

原文地址: http://blog.csdn.net/huang_xw/article/details/7318554

/** * @Description: 两个线程(线程1与线程2)访问同一个对象的内同步方法syn1()与同步方法syn2() *  结果: 线程1访问对象sameObj的同步方法syn1()时, 线程2访问对象sameObj中的同步方法syn2()阻塞. 或者线程2访问时, 线程1阻塞. *  结论: 通常知道不同线程访问同一个对象的相同同步方法时, 线程间是互斥的.  *                    实际上, 不同线程访问同一个对象的不同同步方法时, 线程间也是互斥的.  *                    将同步方法换成同步块结论也是成立的. 关键的因素在于: 一个对象就一把锁. * @author snoopy * @blog http://blog.csdn.net/huang_xw */package basic.b_syn;import org.apache.log4j.Logger;public class TestSynC {private static Logger logger = Logger.getLogger(TestSynC.class);// 线程1static class T1 implements Runnable {TestSynC s;public T1(TestSynC sameObj) {this.s = sameObj;}// 线程1访问同步方法1public void run() {logger.debug("启动线程1...........");s.syn1();logger.debug("退出线程1...........");}}// 线程2static class T2 implements Runnable {TestSynC s;public T2(TestSynC sameObj) {this.s = sameObj;}// 线程2访问同步方法2public void run() {logger.debug("启动线程2...........");s.Syn2();logger.debug("退出线程2...........");}}// 对象的同步方法1public synchronized void syn1() {logger.debug("▲▲▲▲▲▲线程1开始访问同步方法1");try {logger.debug("线程1正在访问同步方法1!!!");Thread.sleep(3000);} catch (InterruptedException e) {e.printStackTrace();}logger.debug("▲▲▲▲▲▲线程1退出同步方法1");}// 对象的同步方法2public synchronized void Syn2() {logger.debug("●●●●●●线程2开始访问同步方法2");for (int i = 0; i < 5; i++) {try {logger.debug("线程2正在访问同步方法2!!!");Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}}logger.debug("●●●●●●线程2退出同步方法2");}public static void main(String[] args) {// 这是多线程要访问的同一个对象TestSynC sameObj = new TestSynC();// 线程1访问同步方法1, 线程2同样也访问同步方法2.Thread t1 = new Thread(new T1(sameObj));Thread t2 = new Thread(new T2(sameObj));t1.start();t2.start();}}

执行结果:

0    [Thread-0] DEBUG basic.b_syn.TestSynC - 启动线程1...........1    [Thread-0] DEBUG basic.b_syn.TestSynC - ▲▲▲▲▲▲线程1开始访问同步方法11    [Thread-0] DEBUG basic.b_syn.TestSynC - 线程1正在访问同步方法1!!!1    [Thread-1] DEBUG basic.b_syn.TestSynC - 启动线程2...........3001 [Thread-0] DEBUG basic.b_syn.TestSynC - ▲▲▲▲▲▲线程1退出同步方法13001 [Thread-0] DEBUG basic.b_syn.TestSynC - 退出线程1...........3001 [Thread-1] DEBUG basic.b_syn.TestSynC - ●●●●●●线程2开始访问同步方法23001 [Thread-1] DEBUG basic.b_syn.TestSynC - 线程2正在访问同步方法2!!!4001 [Thread-1] DEBUG basic.b_syn.TestSynC - 线程2正在访问同步方法2!!!5001 [Thread-1] DEBUG basic.b_syn.TestSynC - 线程2正在访问同步方法2!!!6002 [Thread-1] DEBUG basic.b_syn.TestSynC - 线程2正在访问同步方法2!!!7002 [Thread-1] DEBUG basic.b_syn.TestSynC - 线程2正在访问同步方法2!!!8006 [Thread-1] DEBUG basic.b_syn.TestSynC - ●●●●●●线程2退出同步方法28007 [Thread-1] DEBUG basic.b_syn.TestSynC - 退出线程2...........