我可以仅使用套接字在Java和C＃之间进行通信吗？

Question

更具体地说，如果计算机上有服务器（java.net.ServerSocket实例），我可以使用C＃System.Net.Sockets.Socket实例连接到该服务器吗？

Answer 1

主要问题是您需要非常小心发送和接收的数据的编码。这是一对可以协同工作的程序。C＃客户端发送字符串，方法是首先发送其长度为整数，然后发送字符串本身的字节。Java服务器读取长度，然后读取消息并将输出打印到控制台。然后编写回显消息，计算其长度，提取字节并将其发送回C＃客户端。客户端读取长度，消息并打印输出。应该有一种方法来避免所有按位排列的东西，但是老实说，我对此东西有些不满意，尤其是在Java方面。

Java服务器：

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class JavaSocket {

    public static void main(String[] args) throws IOException {

        ServerSocket serverSocket = new ServerSocket(4343, 10);
        Socket socket = serverSocket.accept();
        InputStream is = socket.getInputStream();
        OutputStream os = socket.getOutputStream();

        // Receiving
        byte[] lenBytes = new byte[4];
        is.read(lenBytes, 0, 4);
        int len = (((lenBytes[3] & 0xff) << 24) | ((lenBytes[2] & 0xff) << 16) |
                  ((lenBytes[1] & 0xff) << 8) | (lenBytes[0] & 0xff));
        byte[] receivedBytes = new byte[len];
        is.read(receivedBytes, 0, len);
        String received = new String(receivedBytes, 0, len);

        System.out.println("Server received: " + received);

        // Sending
        String toSend = "Echo: " + received;
        byte[] toSendBytes = toSend.getBytes();
        int toSendLen = toSendBytes.length;
        byte[] toSendLenBytes = new byte[4];
        toSendLenBytes[0] = (byte)(toSendLen & 0xff);
        toSendLenBytes[1] = (byte)((toSendLen >> 8) & 0xff);
        toSendLenBytes[2] = (byte)((toSendLen >> 16) & 0xff);
        toSendLenBytes[3] = (byte)((toSendLen >> 24) & 0xff);
        os.write(toSendLenBytes);
        os.write(toSendBytes);

        socket.close();
        serverSocket.close();
    }
}

AC＃客户端：

using System;
using System.Net;
using System.Net.Sockets;

namespace CSharpSocket
{
    class MainClass
    {
        public static void Main (string[] args)
        {
            string toSend = "Hello!";

            IPEndPoint serverAddress = new IPEndPoint(IPAddress.Parse("192.168.0.6"), 4343);

            Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            clientSocket.Connect(serverAddress);

            // Sending
            int toSendLen = System.Text.Encoding.ASCII.GetByteCount(toSend);
            byte[] toSendBytes = System.Text.Encoding.ASCII.GetBytes(toSend);
            byte[] toSendLenBytes = System.BitConverter.GetBytes(toSendLen);
            clientSocket.Send(toSendLenBytes);
            clientSocket.Send(toSendBytes);

            // Receiving
            byte[] rcvLenBytes = new byte[4];
            clientSocket.Receive(rcvLenBytes);
            int rcvLen = System.BitConverter.ToInt32(rcvLenBytes, 0);
            byte[] rcvBytes = new byte[rcvLen];
            clientSocket.Receive(rcvBytes);
            String rcv = System.Text.Encoding.ASCII.GetString(rcvBytes);

            Console.WriteLine("Client received: " + rcv);

            clientSocket.Close();
        }
    }
}