习题-多线程
目录
1.爬山
2.线程优先级的设置
3.模拟医院叫号
4.模拟接力赛跑
5.网络购票
1.爬山
每个线程代表一个人，可设置每人爬山速度，每爬完100米显示信息，爬到终点时给出相应提示。
利用继承实现多线程
public class ClimbThread extends Thread{
//爬100米的时长（线程休眠的时常）
private int time;
//爬多少个100米
private int num;
public ClimbThread(String name,int time,int kilo) {
super(name);
this.time = time;
this.num = kilo*1000/100;
}
public void run() {
//未爬到终点
while (num > 0) {
try {
Thread.sleep(time);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()+"爬完了100米；");
num--;
}
System.out.println(Thread.currentThread().getName()+"到达终点！");
}
}
/*爬山
每个线程代表一个人
可设置每人爬山速度
每爬完100米显示信息
爬到终点时给出相应提示
*/
public class TestClimb {
public static void main(String[] args) {
ClimbThread cThread1 = new ClimbThread("年轻人", 150, 1);
ClimbThread cThread2 = new ClimbThread("老年人", 350, 1);
System.out.println("开始爬山");
cThread1.start();
cThread2.start();
}
}
------------------------------------------------------------------
2.线程优先级的设置
将主线程设置为最高优先级、子线程设置为最低优先级并显示
子线程：
//显示主线程、子线程默认优先级
//将主线程设置为最高优先级、子线程设置为最低优先级并显示
public class MyThread implements Runnable{
@Override
public void run() {
}
}
//获得和设置主线程及子线程的优先级
public class TestThread {
public static void main(String[] args) {
//获得主线程
Thread mainThread = Thread.currentThread();
//创建子线程
Thread thread = new Thread(new MyThread());
System.out.println("***********默认优先级*********");
System.out.println("主线程名："+mainThread.getName()+",优先级："+mainThread.getPriority());
System.out.println("子线程名："+thread.getName()+",优先级："+thread.getPriority());
System.out.println("***********修改默认优先级后*********");
mainThread.setPriority(10);
thread.setPriority(1);
System.out.println("主线程名："+mainThread.getName()+",优先级："+mainThread.getPriority());
System.out.println("子线程名："+thread.getName()+",优先级："+thread.getPriority());
}
}
------------------------------------------------------------------
3.模拟医院叫号
n 某科室一天需看普通号2 0 个，特需号 10 个n 特需号看病 时间是 普通号的 2 倍n 开始时普通号和特需号并行叫号 ，叫 到特需号的概率比普通号 高n当普通号叫完第10号时，要求先看完全部特需号，再看普通号n 使用多线程模拟这一过程
特需号：
package dh07.hospital;
//特需号
public class SpecialThread implements Runnable{
public void run() {
for (int i = 1; i <= 10; i++) {
System.out.println("特需号："+i+"号病人在看病！");
//线程休眠表示看病的过程
try {
Thread.sleep(400);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
package dh07.hospital;
public class CommonThread {
public static void main(String[] args) {
Thread speThread = new Thread(new SpecialThread());
speThread.setPriority(10);
speThread.start();
//模拟医院叫号
for (int i = 1; i <= 20; i++) {
System.out.println("普通号："+i+"号病人再看病！");
try {
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (i == 10) {
try {
speThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
------------------------------------------------------------------
4.模拟接力赛跑
多人参加1000米接力跑，每跑100米换人，每10米显示信息。
package dh07.run;
//创建线程类RunThread
public class RunThread implements Runnable{
//多个选手共同跑1000米
private int meters = 1000;
//实现一个选手拿到接力棒跑100米的过程
public void run() {
while (true) {
//同步代码块确保在跑步的只有一个人
synchronized (this) {
if (meters<100) {
break;
}
System.out.println(Thread.currentThread().getName()+"拿到了接力棒！");
for (int i = 10; i <= 100; i += 10) {
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()+"跑了"+i+"米");
}
//剩余路途减少100米
meters -= 100;
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
package dh07.run;
public class TestRun {
public static void main(String[] args) {
Runnable runnable = new RunThread();
Thread thread1 = new Thread(runnable,"1号选手");
Thread thread2 = new Thread(runnable,"2号选手");
Thread thread3 = new Thread(runnable,"3号选手");
Thread thread4 = new Thread(runnable,"4号选手");
thread1.start();
thread2.start();
thread3.start();
thread4.start();
}
}
------------------------------------------------------------------
5.网络购票
三人工抢十张，黄牛党只能抢一张。
package dh07.ticket;
//黄牛党只能抢1张票
public class TicketThread2 implements Runnable {
private int ticket = 10;// 记录车票总数
private int num = 0;// 记录用户抢到了第几张票
public void run() {
while (true) {
if (qiangPiao()) {
break;
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public synchronized boolean qiangPiao() {
// 没有余票，退出循环
if (ticket <= 0) {
return true;
}
// 有余票，则抢票，第一步，修改车票数
ticket--;
num++;
// 第二部：显示出票反馈给用户
System.out.println(Thread.currentThread().getName() + "抢到了第" + num + "张票，剩余" + ticket + "张票。");
if (Thread.currentThread().getName().equals("黄牛党")) {
return true;
}
return false;
}
}
package dh07.ticket;
//黄牛党只能抢1张票
public class TestThread2 {
public static void main(String[] args) {
Runnable runnable = new TicketThread2();
Thread t1 = new Thread(runnable,"A");
Thread t2 = new Thread(runnable,"b");
Thread t3 = new Thread(runnable,"黄牛党");
t1.start();
t2.start();
t3.start();
}
}
