Java中的Socket流程及简单实现

在java中基于socket的网络通信主要是使用ServerSocket及Socket来分别构建服务端和客户端，双方通过发送和接收字节数组来实现数据的交换，其通信流程如下：

 示例代码如下：

服务端Server.java

public class Server {

    public static void main(String[] args) throws IOException {
        ExecutorService executorService = Executors.newCachedThreadPool();
        ServerSocket serverSocket = new ServerSocket(9999);
        System.out.println("server started...");
        while (true) {
            Socket socket = serverSocket.accept();
            System.out.println("client connected...");
            executorService.execute(() -> {
                process(socket);
            });
        }
    }

    public static void process(Socket socket) {
        long threadId = Thread.currentThread().getId();
        String threadName = Thread.currentThread().getName();
        System.out.println("thread id:" + threadId + ", thread name:" + threadName);
        InputStream inputStream = null;
        OutputStream outputStream = null;
        try {
            inputStream = socket.getInputStream();
            byte[] bytes = new byte[1024];
            int read = inputStream.read(bytes);
            System.out.println("client:" + new String(bytes, 0, read));

            outputStream = socket.getOutputStream();
            outputStream.write("hello client".getBytes());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                inputStream.close();
                outputStream.close();
                socket.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

客户端Client.java

public class Client {

    public static void main(String[] args) throws IOException {
        while (true) {
            Socket socket = new Socket("127.0.0.1", 9999);
            OutputStream outputStream = socket.getOutputStream();
            System.out.println("Please input string:");
            Scanner scanner = new Scanner(System.in);
            String msg = scanner.nextLine();
            outputStream.write(msg.getBytes());

            InputStream inputStream = socket.getInputStream();
            byte[] bytes = new byte[1024];
            int read = inputStream.read(bytes);
            System.out.println("Message from server:" + new String(bytes, 0, read).trim());
            socket.close();
        }
    }
}