1.三个售票窗口同时出售20张票

public class Demo1
{public static void main(String[] args){TicketOffice ticketOffice = new TicketOffice(new Object(), 20);new Thread(ticketOffice, "窗口1").start();new Thread(ticketOffice, "窗口2").start();new Thread(ticketOffice, "窗口3").start();}
}class TicketOffice implements Runnable
{private Object object;private int ticketNum;public TicketOffice(java.lang.Object object, int ticketNum){this.object = object;this.ticketNum = ticketNum;}@Overridepublic void run(){while (ticketNum > 0){synchronized (object){if (ticketNum <= 0){System.out.println(Thread.currentThread().getName() + "没有票了");}else{System.out.println(Thread.currentThread().getName() + "卖出了一张票，剩余" + --ticketNum + "张票");try{Thread.sleep(1000L);}catch (InterruptedException e){e.printStackTrace();}}}}}
}

2.创建两个线程，其中一个输出1-52，另外一个输出A-Z。输出格式要求：12A 34B 56C 78D ...

public class Demo2
{public static void main(String[] args){Object object = new Object();new Thread(new Number(object)).start();new Thread(new Character(object)).start();}
}class Number implements Runnable
{private Object object;public Number(Object object){this.object = object;}@Overridepublic void run(){synchronized (object){for (int i = 1; i < 53; i++){if (i > 1 && i % 2 == 1){System.out.print(" ");}System.out.print(i);if (i % 2 == 0){object.notifyAll();try{object.wait();}catch (InterruptedException e){e.printStackTrace();}}}}}
}class Character implements Runnable
{private Object object;public Character(Object object){this.object = object;}@Overridepublic void run(){synchronized (object){for (char i = 'A'; i <= 'Z'; i++){System.out.print(i);object.notifyAll();if (i < 'Z'){try{object.wait();}catch (InterruptedException e){e.printStackTrace();}}}}}
}

3.

启动3个线程打印递增的数字, 线程1先打印1,2,3,4,5, 然后是线程2打印6,7,8,9,10, 然后是线程3打印11,12,13,14,15. 接着再由线程1打印16,17,18,19,20….以此类推, 直到打印到75. 程序的输出结果应该为:

线程1: 1 
线程1: 2 
线程1: 3 
线程1: 4 
线程1: 5

线程2: 6 
线程2: 7 
线程2: 8 
线程2: 9 
线程2: 10 
…

线程3: 71 
线程3: 72
线程3: 73 
线程3: 74 
线程3: 75

public class Demo3
{public static void main(String[] args){Object object = new Object();new Thread(new PrintRunnable(object,1)).start();new Thread(new PrintRunnable(object,2)).start();new Thread(new PrintRunnable(object,3)).start();}}class PrintRunnable implements Runnable
{private static volatile int printNum = 0;private Object object;private int threadId;public PrintRunnable(Object object, int threadId){super();this.object = object;this.threadId = threadId;}@Overridepublic void run(){while (printNum < 75){synchronized (object){if (printNum / 5 % 3 + 1 == threadId){for (int i = 0; i < 5; i++){System.out.println("线程" + threadId + ":" + (++printNum));}object.notifyAll();}else{try{object.wait();}catch (InterruptedException e){e.printStackTrace();}}}}}
}