Java UDP 多人聊天室简易版

服务端

 
 
import java.io.*;
import java.net.*;
import java.util.ArrayList;
public class Server{
    public static ServerSocket server_socket;
    public static ArrayList socketList=new ArrayList();  
    public static void main(String []args){
        try{
            server_socket = new ServerSocket(5000);
            while(true){
                Socket socket = server_socket.accept();
                socketList.add(socket); //把sock对象加入sock集合
                ServerBO_Thread st=new ServerBO_Thread(socket,socketList); //初始化多线程
                st.start();//启动多线程
            }
        }catch(Exception ex){
            ex.printStackTrace();
        }finally{
            try{
                if(server_socket!=null){
                    server_socket.close();
                }
            }catch(Exception ex){
                ex.printStackTrace();
            }
        }
    }
    public void encryptWrite(String src,DataOutputStream output)throws IOException{
        //将一个字符串转化为字符数组
        //System.out.println(src);
        char[] char_arr = src.toCharArray();
        //加密操作
        for(int i = 0;i clients;
    ServerBO_Thread(Socket s,ArrayList ss){//初始化
        client=s;
        clients=ss; 
    }
    public void run(){
        DataInputStream input = null;
        DataOutputStream output =null;
        try{
            input = new DataInputStream(client.getInputStream());
            Server bo = new Server();
            String receive=null;
            String send=null;
            while(true){//监视当前客户端有没有发来消息
                if(!client.isClosed()){
                    receive=bo.readDecrypt(input);
                    clients.trimToSize();
                    String[] param = receive.split("&");
                    if(")start".equals(param[1])){    //分析客户端发来的内容
                        send = param[0]+"进入聊天室";
                    }else{
                        send = param[0]+"说:    "+param[1];
                    }
                    if(!("3333".equals(param[1]))){//3333为退出聊天室信号
                        for(Socket socket:clients){ //遍历socke集合 
                            //把读取到的消息发送给各个客户端  
                            if(!socket.isClosed()){
                                output = new DataOutputStream(socket.getOutputStream());
                                bo.encryptWrite(send,output);
                            }
                        }  
                    }else{//如果有客户端退出
                        for(Socket socket:clients){ //遍历socke集合 
                                if(socket!=client){//告诉其他人此人退出聊天室
                                    if(!(socket.isClosed())){
                                        output = new DataOutputStream(socket.getOutputStream());
                                        bo.encryptWrite(param[0]+"已退出聊天室",output);
                                    }
                                }
                            }
                        output = new DataOutputStream(client.getOutputStream());
                        bo.encryptWrite("3333",output);//返回信号给要退出的客户端，然后关闭线程
                        client.close();
                        input.close();
                        output.close();
                    }
                }else{
                    break;
                }
            }
        }catch(Exception ex){
            ex.printStackTrace();
        }
    }
}

客户端

 
import java.io.IOException;
import java.util.Scanner;
import java.net.*;
import java.io.*;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.BufferedWriter;
import java.io.BufferedReader;
import java.io.DataOutputStream;
public class People{
//服务端ip
    public  String ip = "127.0.0.1";
    //服务端端口
    public  int port = 5000;
    public  DataOutputStream output = null;
    public  Socket socket = null;
    public  DataInputStream input = null;
    public  Scanner sc =new Scanner (System.in);
    public  String send ;
    public  String receive;
    public  String name;
    public String sd = null;
    public static void main(String[]aa){
        People po = new People();
        po.start();
    }
    public void start(){
        try{
            System.out.println("*******欢迎使用匿名聊天室！**********");
            System.out.println("请输入你将要使用的昵称：");
            name=sc.nextLine();//获取昵称
            socket = new Socket(ip,port);
            output=new DataOutputStream(socket.getOutputStream());
            input = new DataInputStream(socket.getInputStream());
            send = name+"&)start";//把昵称发送到server 告诉所有人有新成员加入聊天室
            System.out.println("(如果要退出聊天室请输入“3333”！)");
            System.out.println("*******成功进入匿名聊天室！**********");
            System.out.println("");
            encryptWrite(send,output);
            Out out=new Out(output,name,input,socket);
            out.start();//启动发送聊天内容的多线程
            while(true){    
                String receive = readDecrypt(input);
                if("3333".equals(receive)){//如果收到“3333”则退出聊天室
                    System.out.println("*******成功退出匿名聊天室！**********");
                    input.close();
                    output.close();
                    socket.close();
                    System.exit(0);
                }
                System.out.println(receive);
            }
        }catch(Exception ex){
                ex.printStackTrace();
        }finally{
            try{
                if(socket!=null) socket.close();
                input.close();
                output.close();
            }catch(Exception ex){
                ex.printStackTrace();
            }
        }    
    }
    public void encryptWrite(String src,DataOutputStream output)throws IOException{
        //将一个字符串转化为字符数组
        char[] char_arr = src.toCharArray();
        //加密操作
        for(int i = 0;i

运行结果如下：