1. The difference between wait and sleep
Sleep: do not release the lock object, release the CPU usage rights
During the sleep time, you cannot wake up
wait: release the lock object, release the CPU usage rights
During the waiting time, you can wake up
2. The life cycle of the thread (the switching process of the five states)
New (new Thread)
When an instance (object) of the Thread class is created, the thread enters the newly created state (not started).
For example: Thread t1=new Thread();
The runnable
thread has been started and is waiting to be allocated to the CPU time slice, that is to say, the thread is queuing up in the ready queue to obtain CPU resources at this time. For example: t1.start();
The running (running)
thread obtains CPU resources and is executing tasks (run() method). At this time, unless the thread automatically gives up CPU resources or a thread with a higher priority enters, the thread will run until the end.
Dead (dead)
When the thread is executed or killed by other threads, the thread enters the dead state, and the thread cannot enter the ready state to wait for execution.
Natural termination: terminates after running the run() method normally
Abnormal termination: call the stop() method to stop a thread from running
Blocked (blocked)
For some reason, a running thread yields the CPU and suspends its own execution, that is, it enters a blocked state.
Sleeping: Use the sleep(long t) method to put the thread into sleep mode. A sleeping thread can enter the ready state after the specified time has elapsed.
Waiting: call the wait() method. (Call the notify() method to return to the ready state)
被另一个线程所阻塞：调用suspend()方法。（调用resume()方法恢复）
3、有一个抽奖池,该抽奖池中存放了奖励的金额,该抽奖池用一个数组int[] arr = {10,5,20,50,100,200,500,800,2,80,300};
创建两个抽奖箱(线程)设置线程名称分别为“抽奖箱1”，“抽奖箱2”，随机从arr数组中获取奖项元素并打印在控制台上,格式如下:
抽奖箱1 又产生了一个 10 元大奖
抽奖箱2 又产生了一个 100 元大奖
//.....
1 /** 2 * 抽奖池 3 * 4 * @author vanguard 5 * 6 */ 7 public class PoolThread extends Thread { 8 //定义抽奖池数组 9 private int[] arr = { 10, 5, 20, 50, 100, 200, 500, 800, 2, 80, 300 }; 10 //定义奖金个数 11 private int num = arr.length; 12 //定义标记数组 13 private boolean[] flag = new boolean[num]; 14 public void run() { 15 while (true) { 16 synchronized (this) { 17 if(num > 0) { 18 Random r = new Random(); 19 int index = r.nextInt(arr.length); 20 //如果下标为索引的标记数组为false，代表不重复 21 if(!flag[index]) { 22 //将下标下的标记数组设为true，代表已经用过 23 flag[index] = true; 24 System.out.println(Thread.currentThread().getName() + "又产生了" 25 + arr[index] + "元大奖"); 26 //奖金个数减一 27 num--; 28 } 29 } 30 } 31 32 } 33 } 34 }
1 ** 2 * 3、有一个抽奖池,该抽奖池中存放了奖励的金额,该抽奖池用一个数组int[] arr = {10,5,20,50,100,200,500,800,2,80,300}; 3 创建两个抽奖箱(线程)设置线程名称分别为“抽奖箱1”，“抽奖箱2”，随机从arr数组中获取奖项元素并打印在控制台上,格式如下: 4 5 抽奖箱1 又产生了一个 10 元大奖 6 抽奖箱2 又产生了一个 100 元大奖 7 //..... 8 * @author vanguard 9 * 10 */ 11 public class Demo01 { 12 public static void main(String[] args) { 13 PoolThread pt = new PoolThread(); 14 Thread t0 = new Thread(pt); 15 t0.setName("抽奖箱1"); 16 Thread t1 = new Thread(pt); 17 t1.setName("抽奖箱2"); 18 19 t0.start(); 20 t1.start(); 21 } 22 }
4、某公司组织年会,会议入场时有两个入口,在入场时每位员工都能获取一张双色球彩票,假设公司有100个员工,利用多线程模拟年会入场过程,
并分别统计每个入口入场的人数,以及每个员工拿到的彩票的号码。线程运行后打印格式如下：
编号为: 2 的员工 从后门 入场! 拿到的双色球彩票号码是: [17, 24, 29, 30, 31, 32, 07]
编号为: 1 的员工 从后门 入场! 拿到的双色球彩票号码是: [06, 11, 14, 22, 29, 32, 15]
//.....
从后门入场的员工总共: 13 位员工
从前门入场的员工总共: 87 位员工
1 /** 2 * 员工进入会场，获取双色球彩票，统计每位员工的彩票号码 3 * 前门、后门员工个数 4 * @author vanguard 5 * 6 */ 7 public class Entering implements Runnable { 8 private int frontNum = 0; 9 private int backNum = 0; 10 private static int person = 100; 11 12 public void run() { 13 while(true) { 14 synchronized (this) { 15 String ThreadName = Thread.currentThread().getName(); 16 if(person < 0) { 17 return; 18 } 19 if(person > 0) { 20 if(ThreadName.equals("前门")) { 21 frontNum++; 22 System.out.print("编号为" + (100 - person + 1) + "的员工 从" + ThreadName + " 入场，拿到的双色球彩票号码是:"); 23 person--; 24 getNum(); 25 } 26 if(ThreadName.equals("后门")) { 27 backNum++; 28 System.out.print("编号为" + (100 - person + 1) + "的员工 从" + ThreadName + " 入场，拿到的双色球彩票号码是:"); 29 person--; 30 getNum(); 31 } 32 } 33 if(person == 0) { 34 System.out.println("从前门入场的员工总共: " + frontNum + "位员工"); 35 System.out.println("从后门入场的员工总共: " + backNum + "位员工"); 36 person--; 37 } 38 } 39 } 40 41 42 } 43 44 public void getNum() { 45 List<Integer> list = new ArrayList<Integer>(); 46 for(int i = 0; i < 7; i++) { 47 Random r = new Random(); 48 int num = r.nextInt(30) + 1; 49 if(list.contains(num)) { 50 num = r.nextInt(30) + 1; 51 } 52 list.add(num); 53 } 54 System.out.println(list); 55 } 56 }
/** * 4、某公司组织年会,会议入场时有两个入口,在入场时每位员工都能获取一张双色球彩票,假设公司有100个员工,利用多线程模拟年会入场过程, 并分别统计每个入口入场的人数,以及每个员工拿到的彩票的号码。线程运行后打印格式如下： 编号为: 2 的员工 从后门 入场! 拿到的双色球彩票号码是: [17, 24, 29, 30, 31, 32, 07] 编号为: 1 的员工 从后门 入场! 拿到的双色球彩票号码是: [06, 11, 14, 22, 29, 32, 15] //..... 从后门入场的员工总共: 13 位员工 从前门入场的员工总共: 87 位员工 * @author vanguard * */ public class Demo02 { public static void main(String[] args) { Entering e = new Entering(); Thread t0 = new Thread(e, "前门"); Thread t1 = new Thread(e, "后门"); t0.start(); t1.start(); } }