Java 服务器，C# 客户端。发送数据

Question

所以，我在将数据从 C# 客户端发送到 Java 服务器时遇到了问题。连接正在建立，但我猜我在某个地方搞砸了。

这是服务器端代码

package com.chris.net;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;


public class Server implements Runnable
{
    private String serverName;
    private boolean isRunning;

private ServerSocket serverSocket;
private Socket clientSocket;

public Server(String name, int port)
{
    try 
    {
        this.serverName = name;
        this.serverSocket = new ServerSocket(port);
        this.isRunning = true;
        new Thread(this).start();
    } 
    catch (IOException e) 
    {
        e.printStackTrace();
    }
}

private BufferedReader recv;

public void run()
{
    while(isRunning)
    {
        try 
        {
            clientSocket = serverSocket.accept();
            System.out.println("Client Connected from " + clientSocket.getInetAddress().getHostAddress() + ":" + clientSocket.getPort());

            recv = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

            System.out.println("Data Recieved: " + recv.readLine());

            clientSocket.close();
        }
        catch (IOException e) 
        {
            e.printStackTrace();
        }
    }
}
}

这是客户端代码

lass TCPClient
{
    private TcpClient Client;
    private NetworkStream Stream;

    private Byte[] Data;

    public TCPClient(string address, int port)
    {
        Client = new TcpClient();
        Client.Connect(address, port);

        Stream = Client.GetStream();

        SendData("Test Data");

        while (Client.Connected)
        {

        }
    }

    public void SendData(string message)
    {
        Data = System.Text.Encoding.ASCII.GetBytes(message);
        Stream.Write(Data, 0, Data.Length);

        Console.WriteLine("Sent: {0}", message);
    }
}

服务器注册连接，客户端似乎认为它已经发送了数据，但是我不知道是客户端没有发送数据还是服务器没有接收它。考虑到 Console.Writeline 只是打印出转换为字节的消息，我不知道。

Answer 1

如果您想使用 JSON，请参阅 this 优秀文章，了解让 Java 发送将您的 java 类型序列化为 JSON 的消息以及接收 C# 以将其 Deserealize 为 C# 类型。

Java 中的摘录：

import java.io.IOException;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import com.google.gson.Gson;

public class GuyServer {
 public static void main(String[] args)
 throws IOException {
      Gson gson = new Gson();
      ServerSocket serverSocket = new ServerSocket(16001);
      System.out.println("Listening on port 16001. " 
              + "Press enter to quit "
              + "after the next connection.");
      while (System.in.available() == 0) {
           Socket socket = serverSocket.accept();
           System.out.println("A client has connected." 
               + " Sending a new Guy down the pipe.");
           PrintWriter out =
               new PrintWriter(socket.getOutputStream(),
                   true);
           Guy guy = Guy.getRandomGuy();
           String json = gson.toJson(guy);
           out.print(json);
           out.close();
           socket.close();
       }
      System.out.println("Quitting...");
      serverSocket.close();
  }
}

C#结束：

using System;
using System.IO;
using System.Net.Sockets;
using System.Web.Script.Serialization;

class GuyClient
{
     static void Main(string[] args)
     {
          String input;

          using (TcpClient tcpClient = 
                  new TcpClient("localhost", 16001))
          using (NetworkStream networkStream = 
                  tcpClient.GetStream())
          using (StreamReader streamReader = 
                  new StreamReader(networkStream))
          {
               input = streamReader.ReadToEnd();
           }

          Console.WriteLine("Received data: " + input + "\n");

          JavaScriptSerializer javaScriptSerializer = 
                  new JavaScriptSerializer();
          Guy bob = javaScriptSerializer
                  .Deserialize<Guy>(input) as Guy;
          Console.WriteLine(bob.ToString());
      }
}

Java 类

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class Guy {
     private String name;
     public String getName() {
          return name;
      }     
 }

}

C# 可序列化类

using System;
using System.Collections.Generic;

[Serializable]
class Guy
{
     public string Name { get; set; }    
}

我稍微整理了一下，以便更容易理解。它不会编译，但你明白了。

Answer 2

C# TCP 客户端：（这更新了第一个答案），注意到在 C# 中使用 BinaryWriter 类似于 Java 中的 DataOutputStream：

在代码中的某处定义 MAX_BUFFER_SIZE=1024 (example) 的常量！

public static void WriteString(BinaryWriter os, string value)  {
            if (value!=null) {
                byte[] array = System.Text.Encoding.Unicode.GetBytes(value);
                WriteBuffer(os,array);
            } else {
                WriteInt(os,0);
            }
        }

public static void WriteBuffer(BinaryWriter os, byte[] array) {
            if ((array!=null) && (array.Length > 0) && (array.Length < MAX_BUFFER_SIZE)) {
                WriteInt(os,array.Length);
                os.Write(array);
            } else {
                WriteInt(os,0);
            }
        }

public static void WriteInt(BinaryWriter outStream, int value)  {
            byte[] buffer = BitConverter.GetBytes(value);
            //  Array.Reverse(buffer);
            outStream.Write(buffer);
        }

Answer 3

Java TCP 客户端：您应该分别使用DataInputStream 和DataOutputStream 来发送和接收数据：

try
                    {
                        mOutStream = new DataOutputStream(mClientSocket.getOutputStream());
                        mInStream = new DataInputStream(mClientSocket.getInputStream());
                    }
                    catch (Exception e)
                    {
                        e.printStackTrace();
                    }

操作输出数据流的例子（发送出去）：

public static void WriteString(DataOutputStream os, String value) throws IOException {
        if (value!=null) {
            byte[] array = value.getBytes(CHARSET);
            WriteBuffer(os,array);
        } else {
            WriteInt(os,0);
        }
    }

public static void WriteBuffer(DataOutputStream os, byte[] array) throws IOException {
        if ((array!=null) && (array.length > 0) && (array.length <= MAX_BUFFER_SIZE)) {
            WriteInt(os,array.length);
            os.write(array);
            //os.flush();
        } else {
            WriteInt(os,0);
        }
    }

public static void WriteInt(DataOutputStream os, int value) throws IOException {
        byte[] intAsBytes = ConvertIntToBytes(value);
        os.write(intAsBytes);
        //os.flush();
    }

使用输入流（接收）的例子：

public static String ReadString(DataInputStream is) throws IOException {
        String ret=null;
        int len = ReadInt(is);
        if ((len == 0) || (len > MAX_BUFFER_SIZE)) {
            ret = "";
        } else {
            byte[] buffer = new byte[len];
            is.readFully(buffer, 0, len);
            ret = new String(buffer, CHARSET);
        }
        return (ret);
    }

public static int ReadInt(DataInputStream is) throws IOException {
        int ret=0;
        byte[] intAsBytes = new byte[4];
        // this will just block forever...
        is.readFully(intAsBytes);
        ret = ConvertBytesToInt(intAsBytes);
        return (ret);
    }

public static int ConvertBytesToInt( byte[] array) {
        int rv = 0;
        for ( int x = 3; x >= 0; x-- )
        {
            long bv = array[ x ];
            if ( x < 3 & bv < 0 ) // keeping the sign intact???
                bv +=256;
            //rv *= 256;
            rv = rv << 8;
            rv += bv;
        }
        return rv;
    }