一個 Java 的 Socket 服務器和客戶端通信的例子

http://blog.csdn.net/defonds/article/details/7971259

多個客戶端對應一個服務端的通信的一個小例子。

 服務端和客戶端代碼：

public class Server {
    /**
     * 監聽的端口
     */
    public static final int PORT = 12345;

    public static void main(String[] args) {
        System.out.println("服務器啟動》》》》》》");
        Server server = new Server();
        server.init();
    }

    public void init(){
        try {
            ServerSocket serverSocket = new ServerSocket(PORT);
            while (true){
                //一旦有堵塞，表示服務器與客戶端獲得了連接
                Socket client = serverSocket.accept();
                new HandlerThread(client);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private class HandlerThread implements Runnable{
        private Socket socket;

        public HandlerThread(Socket socket) {
            this.socket = socket;
            new Thread(this).start();
        }
        @Override
        public void run() {
            try {
                //讀取客戶端數據
                DataInputStream input = new DataInputStream(socket.getInputStream());
                //這里要注意和客戶端輸出流的寫方法對應,否則會拋 EOFException
                String clientInputStr = input.readUTF();
                //處理客戶端發送的數據
                System.out.println("客戶端發過來的內容："+clientInputStr);
                //想客戶端發送消息
                DataOutputStream out = new DataOutputStream(socket.getOutputStream());
                System.out.println("請輸入：\t");
                String outStr = new BufferedReader(new InputStreamReader(System.in)).readLine();
                out.writeUTF(outStr);
                out.close();
                input.close();

            } catch (IOException e) {
                System.out.println("服務器異常："+e.getMessage());
            }finally {
                if (socket != null) {
                    try {
                        socket.close();
                    } catch (Exception e) {
                        socket = null;
                        System.out.println("服務端 finally 異常:" + e.getMessage());
                    }
                }
            }
        }
    }

}

public class Client {
    public static final int PORT = 12345;
    public static final String IP_ADDR = "localhost";

    public static void main(String[] args) {
        System.out.println("客戶端啟用》》》》》》");
        System.out.println("當接收到服務器端字符為 \"OK\" 的時候, 客戶端將終止\n");
        while (true){
            Socket socket = null;
            try {
                //創建一個流套接字並將其連接到指定主機上的指定端口號
                socket = new Socket(IP_ADDR,PORT);
                socket.setSoTimeout(5000);
                //讀取服務器端數據
                DataInputStream input = new DataInputStream(socket.getInputStream());
                //向服務器端發送數據
                DataOutputStream out = new DataOutputStream(socket.getOutputStream());
                System.out.print("請輸入: \t");
                String str = new BufferedReader(new InputStreamReader(System.in)).readLine();
                out.writeUTF(str);

                String ret = input.readUTF();
                System.out.println("服務器端返回過來的是: " + ret);

                if (ret.endsWith("OK")) {
                    System.out.println("客戶端將關閉連接");
                    Thread.sleep(500);
                    break;
                }
                out.close();
                input.close();


            } catch (IOException  | InterruptedException e) {
                e.printStackTrace();
            }finally {
                if (socket != null) {
                    try {
                        socket.close();
                    } catch (IOException e) {
                        socket = null;
                        System.out.println("客戶端 finally 異常:" + e.getMessage());
                    }
                }
            }
        }
    }
}