Socket网络编程入门

/**
 * @author Jack
 */
public class Client {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket();
        // 超时时间
        socket.setSoTimeout(3000);
        // 连接本地，端口2000；超时时间3000ms
        socket.connect(new InetSocketAddress(Inet4Address.getLocalHost(), 2000), 3000);
        System.out.println("已发起服务器连接...");
        System.out.println("客户端信息：" + socket.getLocalAddress() + " P:" + socket.getLocalPort());
        System.out.println("服务器信息：" + socket.getInetAddress() + " P:" + socket.getPort());
        try {
            // 发送接收数据
            todo(socket);
        } catch (Exception e) {
            System.out.println("异常关闭");
        }
        // 释放资源
        socket.close();
        System.out.println("客户端已退出～");
    }
    private static void todo(Socket client) throws IOException {
        // 构建键盘输入流
        InputStream in = System.in;
        BufferedReader input = new BufferedReader(new InputStreamReader(in));
        // 得到Socket输出流，并转换为打印流
        OutputStream outputStream = client.getOutputStream();
        PrintStream socketPrintStream = new PrintStream(outputStream);
        // 得到Socket输入流，并转换为BufferedReader
        InputStream inputStream = client.getInputStream();
        BufferedReader socketBufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        boolean flag = true;
        do {
            // 键盘读取一行
            String str = input.readLine();
            // 发送到服务器
            socketPrintStream.println(str);
            // 从服务器读取一行
            String echo = socketBufferedReader.readLine();
            if ("bye".equalsIgnoreCase(echo)) {
                flag = false;
            } else {
                System.out.println(echo);
            }
        } while (flag);
        // 资源释放
        socketPrintStream.close();
        socketBufferedReader.close();
    }
}

/**
 * @author jack
 */
public class Server {
    public static void main(String[] args) throws IOException {
        ServerSocket server = new ServerSocket(2000);
        System.out.println("服务器准备就绪...");
        System.out.println("服务器信息：" + server.getInetAddress() + " P:" + server.getLocalPort());
        // 等待客户端连接
        for (; ; ) {
            // 得到客户端
            Socket client = server.accept();
            // 客户端构建异步线程
            ClientHandler clientHandler = new ClientHandler(client);
            // 启动线程
            clientHandler.start();
        }
    }
    /**
     * 客户端消息处理
     */
    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("新客户端连接：" + socket.getInetAddress() + " P:" + socket.getPort());
            try (// 得到打印流，用于数据输出；服务器回送数据使用
                 PrintStream socketOutput = new PrintStream(socket.getOutputStream());
                 // 得到输入流，用于接收数据
                 BufferedReader socketInput = new BufferedReader(new InputStreamReader(
                         socket.getInputStream()))) {
                do {
                    // 服务器拿到拿到一条数据
                    String str = socketInput.readLine();
                    if ("bye".equalsIgnoreCase(str)) {
                        flag = false;
                        // 回送
                        socketOutput.println("bye");
                    } else {
                        // 打印到屏幕。并回送数据长度
                        System.out.println(str);
                        socketOutput.println("服务器收到了,你发送的长度为 ：" + str.length());
                    }
                } while (flag);
            } catch (Exception e) {
                System.out.println("连接异常断开");
            } finally {
                // 连接关闭
                if (socket != null) {
                    try {
                        socket.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            System.out.println("客户端已退出：" + socket.getInetAddress() + " P:" + socket.getPort());
        }
    }
}