玩转Java多线程(乒乓球比赛)

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虽然代码有点多，但是这样设计也是为了程序的可扩展性，和解耦合

比赛规则如下:

  1.有四个选手, A1和A2为一个队, B1和B2为另一个队. A1首先发球(启动球), 然后B1, A2, B2将最后发球. 每一轮每个选手发6个球.

  2.选手不改变他们的位置.

  3.比赛期间, 双方选手必须轮流发球,并且在同一个队伍的两个选手可以竞争发球.

  4.当轮到某个选手时, 他/她可以调用一个叫做shot(rate) 的随机函数来模拟比赛,在给定概率rate以内,该函数返回 “in”, 否则返回”out”. 例如 rate=85%, 则球在界内的概率为85%, 出界的概率为15%.

  5.如果shot函数返回”in”, 对方选手必须调用shot函数把球打回.

  6.如果shot函数返回”out”, 对方选手赢得1分,随后重新发球.

  7.当每个选手发完6个球后比赛终止.分数多的一方赢得比赛.分数一样多,比赛为平局.

  8.每个选手作为一个线程实现.

直接上源程序：

package Test;

import java.util.HashMap;
import java.util.concurrent.CountDownLatch;
import java.util.logging.Level;
import java.util.logging.Logger;
/**

* @author haibiscuit(本人博客名)
*/
public class TableTennisThreadDemo {

public static void main(String args[]) {

CountDownLatch countDownLatch = new CountDownLatch(4);
double rate = 0.75; //设置选手赢的概率
int sendNum = 6; //每个选手发球次数

//两个队的名字
String team1_Name = TeamController.getTeamName()[0];
String team2_Name = TeamController.getTeamName()[1];

//四个选手名字
String team1_memName1 = TeamController.getTeamMems(team1_Name)[0];
String team1_memName2 = TeamController.getTeamMems(team1_Name)[1];
String team2_memName1 = TeamController.getTeamMems(team2_Name)[0];
String team2_memName2 = TeamController.getTeamMems(team2_Name)[1];

//创建两个队
Team team1 = new Team(team1_Name);
Team team2 = new Team(team2_Name);

//设置对手
TeamController.setTeamRival(team2, team1);
//设置比赛场数
TeamController.setMatchTimes(sendNum*4); //参数为选手数*每个选手的发球数

//创建乒乓球对象
TableTennis tableTennis = new TableTennis(rate);

//创建四个线程类
Thread thread1 = new Thread(new TeamMember(team1_memName1, sendNum, team1, tableTennis, countDownLatch));
Thread thread2 = new Thread(new TeamMember(team1_memName2, sendNum, team1, tableTennis, countDownLatch));
Thread thread3 = new Thread(new TeamMember(team2_memName1, sendNum, team2, tableTennis, countDownLatch));
Thread thread4 = new Thread(new TeamMember(team2_memName2, sendNum, team2, tableTennis, countDownLatch));
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
Logger.getLogger(TableTennisThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
}

thread1.start();
thread2.start();
thread3.start();
thread4.start();

//等待四个选手运行完
try {
countDownLatch.await();
System.out.println("team1得分："+team1.getScore());
System.out.println("team2得分："+team2.getScore());
if(team1.getScore()>team2.getScore()){
System.out.println("恭喜team1队赢!");
}else if(team1.getScore()<team2.getScore()){
System.out.println("恭喜team2队赢！");
}else{
System.out.println("平局了！");
}
} catch (InterruptedException ex) {
Logger.getLogger(TableTennisThreadDemo.class.getName()).log(Level.SEVERE, null, ex);
}
}
}

class TableTennis {

int rate; //赢的频率
volatile int state = 0; //球的状态,0代表发球,1代表传球,默认是发球状态 
String trail = "team1"; //传球的轨迹
String teamTrail = "team1"; //发球的轨迹
volatile boolean isEnd = false; //判断比赛有没有结束
volatile int totalSendNum = 0; //总共发球次数

public int getTotalSendNum() {
return totalSendNum;
}

public void addTotalSendNum() {
this.totalSendNum = ++totalSendNum;
}

public boolean isIsEnd() {
return isEnd;
}

public void setIsEnd(boolean isEnd) {
this.isEnd = isEnd;
}

public String getTeamTrail() {
return teamTrail;
}

public void setTeamTrail(String teamTrail) {
this.teamTrail = teamTrail;
}

public TableTennis(double rate) {
this.rate = (int) (rate * 100);
}

/**
* 判断输赢
*
* @return
*/
public final String shot() {
int randRate = (int) (Math.random() * 100);
if (((100 - randRate) > (this.rate))) {
return "out";
} else {
return "in";
}
}

public int getRate() {
return rate;
}

public void setRate(int rate) {
this.rate = rate;
}

public int getState() {
return state;
}

public void setState(int state) {
this.state = state;
}

public String getTrail() {
return trail;
}

public void setTrail(String trail) {
this.trail = trail;
}

}

class Team {

String teamName; //球队的名称
int score = 0; //球队的得分

public Team(String teamName) {
this.teamName = teamName;
}

public String getTeamName() {
return teamName;
}

public void setTeamName(String teamName) {
this.teamName = teamName;
}

public int getScore() {
return score;
}

public void addScore() {
this.score = ++score;
}

}

class TeamController {

private static final String[] team = {"team1", "team2"}; //比赛队的名称
private static final HashMap<String, String[]> map = new HashMap(); //用于存放各队的队员信息
private static final HashMap<String, Team> rivalTeam = new HashMap(); //用于存放各队的对手
private static int totalMatchTime; //默认0场比赛

static {
map.put(team[0], new String[]{"A1", "A2"}); //初始化team1队球员 
map.put(team[1], new String[]{"B1", "B2"}); //初始化team2队球员
}

//设置各队的对方队伍
public static void setTeamRival(Team rivalTeam1, Team rivalTeam2) {
rivalTeam.put(team[0], rivalTeam1);
rivalTeam.put(team[1], rivalTeam2);
}
public static void setMatchTimes(int time){
totalMatchTime = time;
}
public static int getMatchTimes(){
return totalMatchTime;
}

public static Team getRivalTeam(String teamName) {
return rivalTeam.get(teamName);
}

public static String[] getTeamName() {
return team;
}

public static String[] getTeamMems(String teamName) {
return map.get(teamName);
}
}
//队员

class TeamMember implements Runnable {

Team team; //球员所在的球队
TableTennis tableTennis; //每个队员所传的球
String memName; //球员名称
int sendNum; //每个队员传球的次数

CountDownLatch countDownLatch; //保证每个球员发球次数

public TeamMember(String memName, int sendNum, Team team, TableTennis tableTennis, CountDownLatch countDownLatch) {
this.team = team;
this.tableTennis = tableTennis;
this.memName = memName;
this.sendNum = sendNum;
this.countDownLatch = countDownLatch;
}

@Override
public void run() {
while (!this.tableTennis.isIsEnd()) { //当在发球此数内
sendBall();
}
countDownLatch.countDown();
}

/**
* 发球的逻辑注意这里的synchronized,并发控制
*/
private void sendBall() {
synchronized (tableTennis) {

// System.out.println("当前发球线程:" + Thread.currentThread().getName());
while (!(this.tableTennis.getTrail().equals(this.team.getTeamName()))) { //判断是否是该队传球
// System.out.println("发球睡眠线程:" + Thread.currentThread().getName());
if(this.tableTennis.isIsEnd()){
return;
} 

try {
tableTennis.wait();
} catch (InterruptedException ex) {
Logger.getLogger(TableTennis.class.getName()).log(Level.SEVERE, null, ex);
}
}
if(this.tableTennis.isIsEnd()){ //判断比赛有没有结束，结束直接返回
return;
} 
if (this.tableTennis.getState() == 0) { //判断是不是发球状态
this.sendNum--; //将发球次数减一 
}

//发球的时候判断在界内还是界外
if (this.tableTennis.shot().equals("in")) { //发球表示球在界内
this.tableTennis.setTrail(TeamController.getRivalTeam(this.team.getTeamName()).getTeamName()); //对手接球
this.tableTennis.setState(1); //如果发球在界内，将发球状态改为传球状态
System.out.print(this.memName + "-in-");
} else { //如果在界外，此时还是发球状态
TeamController.getRivalTeam(this.team.getTeamName()).addScore(); //对方队加上一分
System.out.print(this.memName + "-out ");
this.tableTennis.setTeamTrail(TeamController.getRivalTeam(this.tableTennis.getTeamTrail()).getTeamName());
this.tableTennis.setTrail(this.tableTennis.getTeamTrail());
this.tableTennis.setState(0);
this.tableTennis.addTotalSendNum(); //将发球次数加一
if(this.tableTennis.getTotalSendNum()==TeamController.getMatchTimes()){
this.tableTennis.setIsEnd(true);
}
}

//执行完唤醒对手线程
tableTennis.notifyAll();
}
}

}

实现思路:利用多线程的wait和notifyall的方法实现线程切换,核心类是TableTennis类