JAVA实现聊天室（局域网）

JAVA用局域网实现聊天室

类和接口
Server类（服务器端）

package Test;import java.io.IOException;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;public class Server {private static final int SERVER_PORT=30000;//使用CrazyitMap对象来保存每个客户名字和对应输出流之间的对应关系public static CrazyitMap<String,PrintStream> clients=new CrazyitMap<>();public void init(){try( //建立监听的ServerSocketServerSocket ss=new ServerSocket(SERVER_PORT)){//采用死循环来不断地接收来自客户端的请求while(true){Socket socket=ss.accept();new ServerThread(socket).start();}}//如果抛出异常catch (IOException ex){System.out.println("服务器启动失败，是否端口"+SERVER_PORT+"已被占用");}}public static void main(String[] args){Server server=new Server();server.init();}
}

ServerThread类

package Test;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;public class ServerThread extends Thread {private Socket socket;BufferedReader br = null;PrintStream ps = null;//定义一个构造器，用于接收一个Socket来创建ServerThread线程public ServerThread(Socket socket) {this.socket = socket;}public void run() {try {//获取该Socket对应的输入流br = new BufferedReader(new InputStreamReader(socket.getInputStream()));//获取该Socket对应的输出流ps = new PrintStream(socket.getOutputStream());String line = null;while ((line = br.readLine()) != null) {//如果读到的行以CrazyitProtocol.USER_ROUND开始，并以其结束//则可以确定读到的是用户登录的用户名if (line.startsWith(CrazyitProtocol.USER_ROUND) && line.endsWith(CrazyitProtocol.USER_ROUND)) {//得到真实消息String userName = getRealMsg(line);//如果用户名重复if (Server.clients.map.containsKey(userName)) {System.out.println("重复");ps.println(CrazyitProtocol.NAME_REP);} else {System.out.println("成功");ps.println(CrazyitProtocol.LOGIN_SUCCESS);Server.clients.put(userName, ps);}}//如果读到的行以CrazyitProtocol.PRIVATE_ROUND开始，//则可以确定是私聊信息，私聊信息只向特定的输入流发送else if (line.startsWith(CrazyitProtocol.PRIVATE_ROUND) && line.endsWith(CrazyitProtocol.PRIVATE_ROUND)) {//得到真实的消息String userAndMsg = getRealMsg(line);//以SPLIT_SIGN分割字符串，前半是私聊用户，后半是聊天信息String user = userAndMsg.split(CrazyitProtocol.SPLIT_SIGN)[0];String msg = userAndMsg.split(CrazyitProtocol.SPLIT_SIGN)[1];//获取私聊用户对应的输出流，并发送私聊信息Server.clients.map.get(user).println(Server.clients.getKeyByValue(ps) + "悄悄对你说：" + msg);}//公聊要向每一个Socket发送else {//得到真实消息String msg = getRealMsg(line);//遍历clients中的每个输出流for (PrintStream clientPs : Server.clients.valueSet()) {clientPs.println(Server.clients.getKeyByValue(ps) + "说：" + msg);}}}}//捕获到异常后，表明Socket对应的客户端已经出现了问题//所以程序将其对应的输出流从Map中删除catch (IOException e) {Server.clients.removeByValue(ps);System.out.println(Server.clients.map.size());//关闭网络，IO资源try {if (br != null) {br.close();}if (ps != null) {ps.close();}if (socket != null) {socket.close();}} catch (IOException ex) {ex.printStackTrace();}}}//将读到的内容去掉前后协议字符，恢复成真实数据private String getRealMsg(String line) {return line.substring(CrazyitProtocol.PROTOCOL_LEN,line.length()-CrazyitProtocol.PROTOCOL_LEN);}
}

Client类

package Test;import javax.swing.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;public class Client {private static final int SERVER_PORT=30000;private Socket socket;private PrintStream ps;private BufferedReader brServer;private BufferedReader keyIn;public void init(){try{//初始化代表键盘的输入流keyIn=new BufferedReader(new InputStreamReader(System.in));//连接到服务器端socket=new Socket("127.0.0.1",SERVER_PORT);//获取该Socket对应的输入流和输出流ps=new PrintStream(socket.getOutputStream());brServer=new BufferedReader(new InputStreamReader(socket.getInputStream()));String tip=" ";//采用不断循环地弹出对话框要求输入用户名while(true){String userName= JOptionPane.showInputDialog(tip+"输入用户名");//用户输入的用户名前后增加协议字符串后发送ps.println(CrazyitProtocol.USER_ROUND+userName+CrazyitProtocol.USER_ROUND);//读取服务器端的响应String result=brServer.readLine();//如果用户名重复，则开始下一次循环if (result.equals(CrazyitProtocol.NAME_REP)){tip="用户名重复，请重试";continue;}//服务器端登录成功if (result.equals(CrazyitProtocol.LOGIN_SUCCESS)){break;}}}//捕获到异常，关闭网络资源，并退出该程序catch (UnknownHostException ex){System.out.println("找不到远程服务器，请确定服务器已经启动");closeRs();System.exit(1);}catch(IOException ex){System.out.println("网络异常，请重新登录");closeRs();System.exit(1);}//以该Socket对应的输入流启动ClientThread线程new ClientThread(brServer).start();}//定义一个读取键盘输出，并以网络发送的方法private void readAndSend(){try{//不断读取键盘输入String line=null;while ((line=keyIn.readLine())!=null){//如果发送的信号中有冒号，并以//开头，则认为想发送私聊信息if (line.indexOf(":")>0&&line.startsWith("//")){line=line.substring(2);ps.println(CrazyitProtocol.PRIVATE_ROUND+line.split(":")[0]+CrazyitProtocol.SPLIT_SIGN+line.split(":")[1]+CrazyitProtocol.PRIVATE_ROUND);}else{ps.println(CrazyitProtocol.MSG_ROUND+line+CrazyitProtocol.MSG_ROUND);}}}catch (IOException ex){System.out.println("网络通信异常！请重新登录");closeRs();System.exit(1);}}//关闭Socket，输入流，输出流的方法private void closeRs(){try{if (keyIn!=null){ps.close();}if (brServer!=null){ps.close();}if (ps!=null){ps.close();}if (socket!=null){keyIn.close();}}catch (IOException ex){ex.printStackTrace();}}public static void main(String[] args){Client client=new Client();client.init();client.readAndSend();}
}

ClientThread类

package Test;import java.io.BufferedReader;
import java.io.IOException;public class ClientThread extends Thread {//该客户端线程负责处理输入流BufferedReader br=null;//使用一个网络输入流来创建客户端线程public ClientThread(BufferedReader br){this.br=br;}public void run(){try{String line=null;//不断地从输入流中读取数据，并将这些数据打印输出while((line=br.readLine())!=null){System.out.println(line);}}catch (IOException ex){ex.printStackTrace();}finally {try {if (br!=null){br.close();}}catch (IOException ex){ex.printStackTrace();}}}
}

CrazyitMap类

package Test;import java.util.*;public class CrazyitMap<k,v> {//创建一个线程安全的HashMappublic Map<k,v> map= Collections.synchronizedMap(new HashMap<k,v>());//根据value来删除指定项public synchronized void removeByValue(Object value){for (Object key:map.keySet()){if (map.get(key)==value){map.remove(key);break;}}}//获取所有value组成的Set集合public synchronized Set<v> valueSet(){Set<v> result=new HashSet<v>();//将map中的所有value添加到result集合中map.forEach((key,value)->result.add(value));return result;}//根据value查找keypublic synchronized k getKeyByValue(v value){//遍历所有key组成的集合for (k key:map.keySet()){//如果指定key对应的value与被搜索的value相同，则返回对应的keyif(map.get(key)==value||map.get(key).equals(value)){return key;}}return null;}//实现put()方法，该方法不允许value重复public synchronized v put(k key,v value){//遍历所有value组成的集合for (v val:valueSet()){//如果某个value与试图放入集合的value相同//则抛出一个RuntimeException异常if (val.equals(value)&&val.hashCode()==value.hashCode()){throw new RuntimeException("MyMap实例不允许有重复的value");}}return map.put(key,value);}
}

CrazyitProtocol类

package Test;public interface CrazyitProtocol {//定义协议字符串的长度int PROTOCOL_LEN=2;//下面是一些协议字符串，服务器端和客户端交换的信息都应该在前后添加这种特殊字符串String MSG_ROUND="ηθ";String USER_ROUND="∏∑";String LOGIN_SUCCESS="1";String NAME_REP="-1";String PRIVATE_ROUND="★【";String SPLIT_SIGN="卐";
}