我可以使用套接字在Java和C＃之间进行通信吗？

Question

更具体地说，如果一台计算机有一个服务器（一个java.net.ServerSocket实例），我可以使用C＃System.Net.Sockets.Socket实例连接到它吗？

Answer 1

主要问题是您需要非常小心的发送和接收数据的编码。这是一对一起工作的程序。 C＃客户端首先发送一个字符串作为整数发送它的长度，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。然后编写一个echo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。应该有一种方法可以避免所有的按位元素，但老实说我对这些东西有些生疏，特别是在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(); 
    } 
} 

C＃客户：

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(); 
     } 
    } 
}