java通信聊天室简单命令行版

解决思路

创建服务器端，将连接的客户端对应的Socket保存到列表中，接收到客户端消息后，转发给其他客户端。

创建客户端，启动一个线程接收服务器端消息并输出，同时循环从键盘读取消息发送给给服务器端。

具体步骤

服务器端

创建ServerSocket，阻塞接受客户端请求，当连接建立是会产生一个和客户端对应的Socket,保存到静态列表中。

public static List<Socket> socketList = new ArrayList<Socket>();

ServerSocket serverSocket = new ServerSocket(30000);

Socket socket = serverSocket.accept();

socketList.add(socket);

没建立一个链接就启动一个线程，并把当前Socket传入，此线程用来接收客户端消息并发送给其他客户端

public void run() {
try {
String line;
//循环从Socket中读取客户端发来的数据  发送给所有客户端
while ((line = br.readLine()) != null) {
for (Socket s : MyServer.socketList) {
if (s != this.s) {
PrintStream ps = new PrintStream(s.getOutputStream());
ps.println(line);
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}

客户端

新建Socket并指定地址指定端口

Socket s = new Socket("127.0.0.1", 30000);

启动客户端线程，此线程用来接收服务器端消息并输出

new Thread(new ClientThread(s)).start();

BufferedReader循环读取键盘输入，通过PrintSream流输出给服务器端

//打开Socket对应的输出流 输送到服务器端
PrintStream ps = new PrintStream(s.getOutputStream());
String line = null;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
while ((line = br.readLine()) != null) {
ps.println("有人说："+line);
}

效果如图

放马过来

服务器端

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

public class MyServer {
//对应客户端Socket列表
public static List<Socket> socketList = new ArrayList<Socket>();

public static void main(String[] args) throws IOException {
ServerSocket serverSocket = new ServerSocket(30000);
while (true) {
Socket socket = serverSocket.accept();
socketList.add(socket);
new Thread(new ServerThread(socket)).start();
}
}

private static class ServerThread implements Runnable {
Socket s = null;
BufferedReader br = null;

public ServerThread(Socket socket) throws IOException {
this.s = socket;
br = new BufferedReader(new InputStreamReader(s.getInputStream()));
}

public void run() {
try {
String line;
//循环从Socket中读取客户端发来的数据  发送给所有客户端
while ((line = br.readLine()) != null) {
for (Socket s : MyServer.socketList) {
if (s != this.s) {
PrintStream ps = new PrintStream(s.getOutputStream());
ps.println(line);
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

客户端

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;

public class MyClient {
public static void main(String[] args) throws IOException {
Socket s = new Socket("127.0.0.1", 30000);
//启动客户端线程 接受服务器端消息并输出
new Thread(new ClientThread(s)).start();
//打开Socket对应的输出流 输送到服务器端
PrintStream ps = new PrintStream(s.getOutputStream());
String line = null;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
while ((line = br.readLine()) != null) {
ps.println("有人说："+line);
}
}

private static class ClientThread implements Runnable {
Socket s = null;
BufferedReader br = null;
public ClientThread(Socket s) throws IOException {
this.s = s;
br = new BufferedReader(new InputStreamReader(s.getInputStream()));
}

public void run() {
String line = null;
try {
while ((line = br.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}