客戶端

public class Client {
    public static void main(String[] args) {
        // 服務端地址和埠
        final String DEFAULT_SERVER_HOST = "127.0.0.1";
        final Integer DEFAULT_SERVER_PORT = 8888;
        Socket socket = null;
        try {
            // 建立socket
            socket = new Socket(DEFAULT_SERVER_HOST, DEFAULT_SERVER_PORT);
            
 
// 接收訊息
            BufferedReader buffReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            // 傳送訊息
            BufferedWriter buffWriter = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
            String msg = null;
            // 獲取使用者輸入的訊息
            BufferedReader userReader = new
 
 BufferedReader(new InputStreamReader(System.in));
            while (true) {
                String input = userReader.readLine();
                // 寫入客戶端要傳送的訊息。因為服務端用readLine獲取訊息，其以\n為終點，所以要在訊息最後加上\n
                buffWriter.write(input + "\n");
                // 重新整理快取
                buffWriter.flush();
                
 
// 讀取服務端資訊
                msg = buffReader.readLine();
                System.out.println(msg);
                // 如果客戶端輸入quit就可以跳出迴圈、斷開連線了
                if (input.equals("quit")) {
                    break;
                }
            }
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

服務端

public class Server {
    public static void main(String[] args) {
        // 監聽8888埠
        final int DEFAULT_PORT = 8888;
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(DEFAULT_PORT);
            while (true) {
                // 阻塞監聽
                Socket socket = serverSocket.accept();
                System.out.println("Client[" + socket.getPort() + "]Online");
                // 讀取訊息
                BufferedReader buffReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                // 傳送訊息
                BufferedWriter buffWriter = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
                String msg = null;
                while ((msg = buffReader.readLine()) != null) {
                    System.out.println("Client[" + socket.getPort() + "]:" + msg);
                    // 寫入服務端要傳送的訊息
                    buffWriter.write("Server:" + msg + "\n");
                    buffWriter.flush();
                    if (msg.equals("quit")) {
                        System.out.println("Client[" + socket.getPort() + "]:Offline");
                        break;
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}