1、客戶(hù)端

public class Client {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket();
        // 超時(shí)時(shí)間
        socket.setSoTimeout(3000);

        // 連接本地，端口2000；超時(shí)時(shí)間3000ms
        socket.connect(new InetSocketAddress(Inet4Address.getLocalHost(), 2000), 3000);

        System.out.println("已發(fā)起服務(wù)器連接，并進(jìn)入后續(xù)流程～");
        System.out.println("客戶(hù)端信息：" + socket.getLocalAddress() + " P:" + socket.getLocalPort());
        System.out.println("服務(wù)器信息：" + socket.getInetAddress() + " P:" + socket.getPort());

        try {
            // 發(fā)送接收數(shù)據(jù)
            todo(socket);
        } catch (Exception e) {
            System.out.println("異常關(guān)閉");
        }

        // 釋放資源
        socket.close();
        System.out.println("客戶(hù)端已退出～");

    }

    private static void todo(Socket client) throws IOException {
        // 構(gòu)建鍵盤(pán)輸入流
        InputStream in = System.in;
        BufferedReader input = new BufferedReader(new InputStreamReader(in));


        // 得到Socket輸出流，并轉(zhuǎn)換為打印流
        OutputStream outputStream = client.getOutputStream();
        PrintStream socketPrintStream = new PrintStream(outputStream);


        // 得到Socket輸入流，并轉(zhuǎn)換為BufferedReader
        InputStream inputStream = client.getInputStream();
        BufferedReader socketBufferedReader = new BufferedReader(new InputStreamReader(inputStream));

        boolean flag = true;
        do {
            // 鍵盤(pán)讀取一行
            String str = input.readLine();
            // 發(fā)送到服務(wù)器
            socketPrintStream.println(str);


            // 從服務(wù)器讀取一行
            String echo = socketBufferedReader.readLine();
            if ("bye".equalsIgnoreCase(echo)) {
                flag = false;
            } else {
                System.out.println(echo);
            }
        } while (flag);

        // 資源釋放
        socketPrintStream.close();
        socketBufferedReader.close();

    }
}

2、服務(wù)端

public class Server {
    public static void main(String[] args) throws IOException {
        ServerSocket server = new ServerSocket(2000);


        System.out.println("服務(wù)器準(zhǔn)備就緒～");
        System.out.println("服務(wù)器信息：" + server.getInetAddress() + " P:" + server.getLocalPort());


        // 等待客戶(hù)端連接
        for (; ; ) {
            // 得到客戶(hù)端
            Socket client = server.accept();
            // 客戶(hù)端構(gòu)建異步線(xiàn)程
            ClientHandler clientHandler = new ClientHandler(client);
            // 啟動(dòng)線(xiàn)程
            clientHandler.start();
        }

    }

    /**
     * 客戶(hù)端消息處理
     */
    private static class ClientHandler extends Thread {
        private Socket socket;
        private boolean flag = true;

        ClientHandler(Socket socket) {
            this.socket = socket;
        }

        @Override
        public void run() {
            super.run();
            System.out.println("新客戶(hù)端連接：" + socket.getInetAddress() +
                    " P:" + socket.getPort());

            try {
                // 得到打印流，用于數(shù)據(jù)輸出；服務(wù)器回送數(shù)據(jù)使用
                PrintStream socketOutput = new PrintStream(socket.getOutputStream());
                // 得到輸入流，用于接收數(shù)據(jù)
                BufferedReader socketInput = new BufferedReader(new InputStreamReader(
                        socket.getInputStream()));

                do {
                    // 客戶(hù)端拿到一條數(shù)據(jù)
                    String str = socketInput.readLine();
                    if ("bye".equalsIgnoreCase(str)) {
                        flag = false;
                        // 回送
                        socketOutput.println("bye");
                    } else {
                        // 打印到屏幕。并回送數(shù)據(jù)長(zhǎng)度
                        System.out.println(str);
                        socketOutput.println("回送：" + str.length());
                    }

                } while (flag);

                socketInput.close();
                socketOutput.close();

            } catch (Exception e) {
                System.out.println("連接異常斷開(kāi)");
            } finally {
                // 連接關(guān)閉
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            System.out.println("客戶(hù)端已退出：" + socket.getInetAddress() +
                    " P:" + socket.getPort());

        }
    }
}