我使用TCPListner在C＃中编写了一个服务器程序，在Java中使用socket编写了一个客户端程序，但是我无法将复杂的对象从Java客户端发送到C＃服务器。
当我通过将字符串转换为字节数组从Java客户端向C＃服务器发送一个简单的字符串时，
在C＃server中转换回String（使用Encoding.utf8.getstring(bytesArray)）时，它总是在消息开头显示一些无效字符。当我将C＃中的String传递给Java Client时，它显示无效的Header错误。
如果任何人有任何替代方案或知道任何可以解决我的问题的免费API，请帮助我。我已经尝试Java-cs-bridge发送复杂的对象，但它总是在C＃服务器上显示Exception。
以下是代码：
C＃服务器代码 - 主要功能
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.IO;
namespace netSocketServer
{
class Program
{
static void Main(string[] args)
{
TcpListener server = new TcpListener(IPAddress.Any, 8888);
var IP = Dns.GetHostEntry(Dns.GetHostName()).AddressList.Where(ip =>ip.AddressFamily == AddressFamily.InterNetwork).Select(ip =>ip).FirstOrDefault();
server.Start();
Console.WriteLine("Server is Running at " + IP.ToString());
TcpClient clientSocket = server.AcceptTcpClient();
Console.WriteLine("Client Connected ... ");
Writer wr = new Writer(clientSocket);
wr.start();
Reader r = new Reader(clientSocket);
r.start();
Console.Read();
}
}
}
C＃服务器读取器类
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Net.Sockets;
using System.Net;
using System.IO;
namespace netSocketServer
{
class Reader
{
TcpClient socket;
NetworkStream ns;
public Reader(TcpClient s)
{
socket = s;
ns = socket.GetStream() ;
}
public void start()
{
new Thread(
t => {
while (true)
{
try
{
int size = ns.ReadByte();
byte[] buff = new byte[size];
ns.Read(buff,0,size);
String message = Encoding.UTF8.getString(buff);
Console.WriteLine("Message from Client : {0}",message);
ns.Flush();
}
catch (Exception e)
{
Console.WriteLine("Client Disconnected : " + e.Message);
}
}
}).Start();
}
}
}
C＃服务器编写器类
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Sockets;
using System.Text;
using System.Threading;
namespace netSocketServer
{
class Writer
{
TcpClient socket;
NetworkStream ns;
public Writer(TcpClient s)
{
socket = s;
ns = socket.GetStream();
}
public void start()
{
new Thread(
t => {
while (true)
{
try
{
Console.Write("Please Enter your Message : ");
string Message = Console.ReadLine();
byte[] buff = Encoding.UTF8.GetBytes(Message);
byte size = (byte)Message.Length;
ns.WriteByte(size);
ns.Write(buff, 0, buff.Length);
ns.Flush();
}
catch(IOException e)
{
Console.WriteLine("Client Disconnected : " + e.Message);
socket.Close();
Thread.CurrentThread.Abort();
Console.WriteLine("Press any key to Closse Server .... ");
}
}
}).Start();
}
}
}
Java客户端 - 主要功能
package javaclient.net;
import java.io.IOException;
import java.net.Socket;
import java.util.Scanner;
/**
*
* @author Numan
*/
public class JavaClientNet {
/**
* @param args the command line arguments
*/
public static void main(String[] args)
{
Socket socket;
Read r;
Writer wr;
Scanner s = new Scanner(System.in);
try
{
// TODO code application logic here
System.out.print("Please Enter Server IP : ");
socket = new Socket(s.next(), 8888);
wr = new Writer(socket);
wr.start();
r = new Read(socket);
r.start();
}
catch (IOException ex)
{
System.out.println(ex.getMessage());
}
}
}
Java客户端 - 读者类
package javaclient.net;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.net.Socket;
/**
*
* @author Numan
*/
public class Read extends Thread
{
Socket socket;
ObjectInputStream inStream;
Read(Socket s)
{
socket = s;
try {
inStream = new ObjectInputStream(socket.getInputStream());
}
catch (IOException ex)
{
System.out.println(ex.getMessage());
}
}
@Override
public void run()
{
while(true)
{
try
{
String str;
byte size = inStream.readByte();
byte[] buf = new byte[size];
inStream.read(buf);
str = new String(buf);
System.out.println("Message form Server : "+str);
}
catch(IOException e)
{
System.out.println(e.getMessage());
Thread.currentThread().stop();
}
}
}
}
Java客户端 - 编写器类
package javaclient.net;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.util.Scanner;
import javacsconverter.core.tobyte.ToByteConvertHelper;
/**
*
* @author Numan
*/
public class Writer extends Thread
{
Socket socket;
ObjectOutputStream outStream;
Scanner scanner = new Scanner(System.in);
Writer(Socket s)
{
socket =s;
try
{
outStream = new ObjectOutputStream(socket.getOutputStream());
}
catch (IOException ex)
{
System.out.println(ex.getMessage());
}
}
@Override
public void run()
{
while(true)
{
try
{
System.out.print("Please Enter Your Message : ");
String str = scanner.nextLine();
byte[] buff = str.getBytes();
outStream.write(buff);
outStream.flush();
}
catch (IOException ex)
{
System.out.println(ex.getMessage());
}
}
}
}
答案 0 :(得分：4)
请不要中止线程（C＃和Java）。
存在数据争用，因为多个线程使用静态Console类：
Program.Main()方法调用Console.Read()方法; Writer.start()方法调用Console.ReadLine()方法。请考虑将Console.Read()方法的Program.Main()方法调用替换为不同的方法，例如Thread.Sleep(Timeout.Infinite)。
有一个错误 - Stream.Read()方法不能保证一次读取指定“大小”的数组（一次调用），返回值应该用于确定读取的实际字节数。让我们看看最初的实现：
int size = ns.ReadByte();
byte[] buff = new byte[size];
// The Stream.Read() method does not guarantee to read the **whole array** "at once".
// Please use the return value of the method.
ns.Read(buff, 0, size);
String message = Encoding.UTF8.GetString(buff);
更正版本：
/// <summary>
/// Helper method to read the specified byte array (number of bytes to read is the size of the array).
/// </summary>
/// <param name="inputStream">Input stream.</param>
/// <param name="buffer">The output buffer.</param>
private static void ReadFully(Stream inputStream, byte[] buffer)
{
if (inputStream == null)
{
throw new ArgumentNullException("inputStream");
}
if (buffer == null)
{
throw new ArgumentNullException("buffer");
}
int totalBytesRead = 0;
int bytesLeft = buffer.Length;
if (bytesLeft <= 0)
{
throw new ArgumentException("There is nothing to read for the specified buffer", "buffer");
}
while (totalBytesRead < buffer.Length)
{
var bytesRead = inputStream.Read(buffer, totalBytesRead, bytesLeft);
if (bytesRead > 0)
{
totalBytesRead += bytesRead;
bytesLeft -= bytesRead;
}
else
{
throw new InvalidOperationException("Input stream reaches the end before reading all the bytes");
}
}
}
public void start()
{
...
int size = ns.ReadByte();
byte[] buff = new byte[size];
ReadFully(ns, buff);
using (var memoryStream = new MemoryStream(buff, false))
{
// The StreamReader class is used to extract the UTF-8 string which is encoded with the byte order mark (BOM).
using (var streamReader = new StreamReader(memoryStream, Encoding.UTF8))
{
string message = streamReader.ReadToEnd();
Console.WriteLine("Message from Client: {0}", message);
}
}
...
}
首先，要描述和确定字节，文本流的顺序考虑包括每个消息的the byte order mark (BOM)（例如）。
此外，还有一个错误 - 发送错误的“缓冲区长度”值。让我们看看最初的实现：
string Message = Console.ReadLine();
byte[] buff = Encoding.UTF8.GetBytes(Message);
// Problem: instead of the length of the string, the size of byte array must be used
// because the UTF-8 encoding is used: generally, string length != "encoded number of bytes".
byte size = (byte)Message.Length;
ns.WriteByte(size);
ns.Write(buff, 0, buff.Length);
ns.Flush();
更正版本：
// UTF-8 with BOM.
var encoding = new UTF8Encoding(true);
// Buffer encoded as UTF-8 with BOM.
byte[] buff = encoding.GetPreamble()
.Concat(encoding.GetBytes(message))
.ToArray();
// Size of the encoded buffer.
byte size = Convert.ToByte(buff.Length);
ns.WriteByte(size);
ns.Write(buff, 0, buff.Length);
ns.Flush();
备用更正版本 - StreamWriter类用于将字符串编码为带字节顺序标记（BOM）的UTF-8：
string message = Console.ReadLine();
using (var memoryStream = new MemoryStream())
{
using (var streamWriter = new StreamWriter(memoryStream, Encoding.UTF8, 1024, true))
{
streamWriter.Write(message);
}
memoryStream.Flush();
byte size = Convert.ToByte(memoryStream.Length);
ns.WriteByte(size);
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(ns);
ns.Flush();
}
首先，请考虑使用DataInputStream类，因为根据问题，以下陈述不正确：
ObjectInputStream对先前使用ObjectOutputStream编写的基元数据和对象进行反序列化。
- java.io.ObjectInputStream class, Java™ Platform Standard Ed. 7。
流的实例化几乎相同：
inStream = new DataInputStream(socket.getInputStream());
其次，有一个错误 - 读取字节数组，但忽略返回值（实际读取的字节数）：
String str;
byte size = inStream.readByte();
byte[] buf = new byte[size];
// The InputStream.read() method does not guarantee to read the **whole array** "at once".
// Please use the return value of the method.
inStream.read(buf);
str = new String(buf);
第三，如上所述，包括字节顺序标记（BOM）。
更正版本：
// Note: inStream must be an instance of DataInputStream class.
byte size = inStream.readByte();
byte[] buf = new byte[size];
// The DataInputStream.readFully() method reads the number of bytes required to fill the buffer entirely.
inStream.readFully(buf);
// Create in-memory stream for the byte array and read the UTF-8 string.
try (ByteArrayInputStream inputStream = new ByteArrayInputStream(buf);
// The BOMInputStream class belongs to Apache Commons IO library.
BOMInputStream bomInputStream = new BOMInputStream(inputStream, false)) {
String charsetName = bomInputStream.getBOMCharsetName();
// The IOUtils class belongs to Apache Commons IO library.
String message = IOUtils.toString(bomInputStream, charsetName);
System.out.println("Message form Server : " + message);
}
有一个错误 - 未明确指定编码。让我们看看最初的实现：
String str = scanner.nextLine();
byte[] buff = str.getBytes();
更正版本：
String str = scanner.nextLine();
byte[] byteOrderMarkBytes = ByteOrderMark.UTF_8.getBytes();
byte[] stringBytes = str.getBytes(StandardCharsets.UTF_8);
// The ArrayUtils.addAll() method belongs to Apache Commons Lang library.
byte[] buff = ArrayUtils.addAll(byteOrderMarkBytes, stringBytes);
outStream.writeByte(buff.length);
outStream.write(buff);
outStream.flush();
备用更正版本 - ByteArrayOutputStream类用于连接数组：
String str = scanner.nextLine();
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
byte[] byteOrderMarkBytes = ByteOrderMark.UTF_8.getBytes();
byteArrayOutputStream.write(byteOrderMarkBytes);
byte[] stringBytes = str.getBytes(StandardCharsets.UTF_8);
byteArrayOutputStream.write(stringBytes);
byteArrayOutputStream.flush();
byte[] buff = byteArrayOutputStream.toByteArray();
outStream.writeByte(buff.length);
outStream.write(buff);
outStream.flush();
希望这有帮助！