package cn.galc.test;public class TestThread6 { public static void main(String args[]) { MyThread4 t4 = new MyThread4(); MyThread5 t5 = new MyThread5(); Thread t1 = new Thread(t4); Thread t2 = new Thread(t5); t1.setPriority(Thread.NORM_PRIORITY + 3);// 使用setPriority()方法設(shè)置線程的優(yōu)先級(jí)別，這里把t1線程的優(yōu)先級(jí)別進(jìn)行設(shè)置 /*  * 把線程t1的優(yōu)先級(jí)(priority)在正常優(yōu)先級(jí)(NORM_PRIORITY)的基礎(chǔ)上再提高3級(jí)   * 這樣t1的執(zhí)行一次的時(shí)間就會(huì)比t2的多很多 　　　　  * 默認(rèn)情況下NORM_PRIORITY的值為5  */ t1.start(); t2.start(); System.out.println("t1線程的優(yōu)先級(jí)是：" + t1.getPriority()); // 使用getPriority()方法取得線程的優(yōu)先級(jí)別，打印出t1的優(yōu)先級(jí)別為8 }}class MyThread4 implements Runnable { public void run() { for (int i = 0; i <= 1000; i++) {  System.out.println("T1：" + i); } }}class MyThread5 implements Runnable { public void run() { for (int i = 0; i <= 1000; i++) {  System.out.println("===============T2：" + i); } }}　　run()方法一結(jié)束，線程也就結(jié)束了。

package cn.galc.test;public class TestSync implements Runnable { Timer timer = new Timer(); public static void main(String args[]) { TestSync test = new TestSync(); Thread t1 = new Thread(test); Thread t2 = new Thread(test); t1.setName("t1");// 設(shè)置t1線程的名字 t2.setName("t2");// 設(shè)置t2線程的名字 t1.start(); t2.start(); } public void run() { timer.add(Thread.currentThread().getName()); }}class Timer { private static int num = 0; public/* synchronized */void add(String name) {// 在聲明方法時(shí)加入synchronized時(shí)表示在執(zhí)行這個(gè)方法的過程之中當(dāng)前對(duì)象被鎖定 synchronized (this) {  /*  * 使用synchronized(this)來鎖定當(dāng)前對(duì)象，這樣就不會(huì)再出現(xiàn)兩個(gè)不同的線程同時(shí)訪問同一個(gè)對(duì)象資源的問題了 只有當(dāng)一個(gè)線程訪問結(jié)束后才會(huì)輪到下一個(gè)線程來訪問  */  num++;  try {  Thread.sleep(1);  } catch (InterruptedException e) {  e.printStackTrace();  }  System.out.println(name + "：你是第" + num + "個(gè)使用timer的線程"); } }}

package cn.galc.test;/*這個(gè)小程序模擬的是線程死鎖的問題*/public class TestDeadLock implements Runnable { public int flag = 1; static Object o1 = new Object(), o2 = new Object(); public void run() { System.out.println(Thread.currentThread().getName() + "的flag=" + flag); /*  * 運(yùn)行程序后發(fā)現(xiàn)程序執(zhí)行到這里打印出flag以后就再也不往下執(zhí)行后面的if語句了   * 程序也就死在了這里，既不往下執(zhí)行也不退出  */ /* 這是flag=1這個(gè)線程 */ if (flag == 1) {  synchronized (o1) {  /* 使用synchronized關(guān)鍵字把對(duì)象01鎖定了 */  try {   Thread.sleep(500);  } catch (InterruptedException e) {   e.printStackTrace();  }  synchronized (o2) {   /*   * 前面已經(jīng)鎖住了對(duì)象o1，只要再能鎖住o2，那么就能執(zhí)行打印出1的操作了    * 可是這里無法鎖定對(duì)象o2，因?yàn)樵诹硗庖粋€(gè)flag=0這個(gè)線程里面已經(jīng)把對(duì)象o1給鎖住了    * 盡管鎖住o2這個(gè)對(duì)象的線程會(huì)每隔500毫秒睡眠一次，可是在睡眠的時(shí)候仍然是鎖住o2不放的   */   System.out.println("1");  }  } } /*  * 這里的兩個(gè)if語句都將無法執(zhí)行，因?yàn)橐呀?jīng)造成了線程死鎖的問題   * flag=1這個(gè)線程在等待flag=0這個(gè)線程把對(duì)象o2的鎖解開，   * 而flag=0這個(gè)線程也在等待flag=1這個(gè)線程把對(duì)象o1的鎖解開   * 然而這兩個(gè)線程都不愿意解開鎖住的對(duì)象，所以就造成了線程死鎖的問題  */ /* 這是flag=0這個(gè)線程 */ if (flag == 0) {  synchronized (o2) {  /* 這里先使用synchronized鎖住對(duì)象o2 */  try {   Thread.sleep(500);  } catch (InterruptedException e) {   e.printStackTrace();  }  synchronized (o1) {   /*   * 前面已經(jīng)鎖住了對(duì)象o2，只要再能鎖住o1，那么就能執(zhí)行打印出0的操作了 可是這里無法鎖定對(duì)象o1，因?yàn)樵诹硗庖粋€(gè)flag=1這個(gè)線程里面已經(jīng)把對(duì)象o1給鎖住了 盡管鎖住o1這個(gè)對(duì)象的線程會(huì)每隔500毫秒睡眠一次，可是在睡眠的時(shí)候仍然是鎖住o1不放的   */   System.out.println("0");  }  } } } public static void main(String args[]) { TestDeadLock td1 = new TestDeadLock(); TestDeadLock td2 = new TestDeadLock(); td1.flag = 1; td2.flag = 0; Thread t1 = new Thread(td1); Thread t2 = new Thread(td2); t1.setName("線程td1"); t2.setName("線程td2"); t1.start(); t2.start(); }}

package cn.galc.test;/* 范例名稱：生產(chǎn)者--消費(fèi)者問題 * 源文件名稱：ProducerConsumer.java * 要 點(diǎn)： * 1. 共享數(shù)據(jù)的不一致性/臨界資源的保護(hù) * 2. Java對(duì)象鎖的概念 * 3. synchronized關(guān)鍵字/wait()及notify()方法 */public class ProducerConsumer { public static void main(String args[]){  SyncStack stack = new SyncStack();  Runnable p=new Producer(stack);  Runnable c = new Consumer(stack);  Thread p1 = new Thread(p);  Thread c1 = new Thread(c);    p1.start();  c1.start(); }}class SyncStack{ //支持多線程同步操作的堆棧的實(shí)現(xiàn) private int index = 0; private char []data = new char[6];  public synchronized void push(char c){ if(index == data.length){ try{  this.wait(); }catch(InterruptedException e){} } this.notify(); data[index] = c; index++; } public synchronized char pop(){ if(index ==0){  try{  this.wait();  }catch(InterruptedException e){} } this.notify(); index--; return data[index]; }}class Producer implements Runnable{ SyncStack stack;  public Producer(SyncStack s){ stack = s; } public void run(){ for(int i=0; i<20; i++){  char c =(char)(Math.random()*26+'A');  stack.push(c);  System.out.println("produced："+c);  try{       Thread.sleep((int)(Math.random()*1000));   }catch(InterruptedException e){  } } }}class Consumer implements Runnable{ SyncStack stack;  public Consumer(SyncStack s){ stack = s; } public void run(){ for(int i=0;i<20;i++){  char c = stack.pop();  System.out.println("消費(fèi)："+c);  try{       Thread.sleep((int)(Math.random()*1000));  }catch(InterruptedException e){  } } }}