本文例項講述了Java使用TCP套接字實現多人聊天功能。分享給大家供大家參考，具體如下：

廢話不多說，直接開搞：

先建立一個服務端：

package interWebWriterEven2;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
/**
 * 服務端
 * @author
 *
 */
public class ServiceT {
    static ArrayList<Socket> list = new ArrayList<Socket>();
    public static void main(String[] args) {
        ServerSocket server;
        try {
            server = new ServerSocket(9999);
            while(true){
                Socket socket = server.accept();
                System.out.println(socket.getInetAddress().getHostName()+"連線成功。IP："+socket.getInetAddress().getHostAddress());
                list.add(socket);
                ServiceThreadT t =new ServiceThreadT(socket);
                t.start();
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

接著是服務端的執行緒：

package interWebWriterEven2;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
/**
 * 服務端執行緒
 * @author
 *
 */
public class ServiceThreadT extends Thread{
    private Socket socket;
    public Socket getSocket() {
        return socket;
    }
    public void setSocket(Socket socket) {
        this.socket = socket;
    }
    public ServiceThreadT(Socket socket) {
        super();
        this.socket = socket;
    }
    @Override
    public void run() {
        try {
            @SuppressWarnings("resource")
            BufferedWriter wFile = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("D://messagesT.txt",true)));
            BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            String strOut = "";
            String strIn = "";
            while(true){
                strIn = socket.getInetAddress().getHostName()+":"+br.readLine();
                strOut = strIn;
                wFile.write(strIn);
                wFile.newLine();
                wFile.flush();
                for (Socket soc : ServiceT.list) {
                    if(soc != socket){
                        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(soc.getOutputStream()));
                        bw.write(strOut);
                        System.out.println(strOut);
                        bw.newLine();
                        bw.flush();
                    }
                }
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

然後是客戶端（應用端）：

package interWebWriterEven2;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.Socket;
/**
 * 客戶端
 * @author
 *
 */
public class ClientT {
    public static void main(String[] args) {
        try {
            Socket socket = new Socket("127.0.0.1",9999);
            ClientThreadT t = new ClientThreadT(socket);
            t.start();
            BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            String strIn = "";
            while(true){
                strIn = br.readLine();
                System.out.println(strIn);
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

最後是客戶端的執行緒：

package interWebWriterEven2;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.util.Scanner;
/**
 * 客戶端的執行緒
 * @author
 *
 */
public class ClientThreadT extends Thread{
    private Socket socket;
    public Socket getSocket() {
        return socket;
    }
    public void setSocket(Socket socket) {
        this.socket = socket;
    }
    public ClientThreadT(Socket socket) {
        super();
        this.socket = socket;
    }
    @Override
    public void run() {
        @SuppressWarnings("resource")
        Scanner sc = new Scanner(System.in);
        try {
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
            while(true){
                System.out.println();
                bw.write(sc.nextLine().trim());
                bw.newLine();
                bw.flush();
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

先執行服務端哦，否則將會報空指標異常的。

更多關於java相關內容感興趣的讀者可檢視本站專題：《Java Socket程式設計技巧總結》、《Java檔案與目錄操作技巧彙總》、《Java資料結構與演算法教程》、《Java操作DOM節點技巧總結》和《Java快取操作技巧彙總》

希望本文所述對大家java程式設計有所幫助。