我用Java编写的客户端能够用Java与服务器通信。 C ++客户端不使用用java编写的服务器。有人可以帮我解决这个问题。我提供了所有3个代码（Java服务器，Java客户端，C ++客户端）
C ++客户端：
#include <iostream>
#include <conio.h>
#include <winsock2.h>
#include<string>
int main(int argc, char* argv[])
{
WSAData version; //We need to check the version.
WORD mkword=MAKEWORD(2,2);
int what=WSAStartup(mkword,&version);
if(what!=0){
std::cout<<"This version is not supported! - \n"<<WSAGetLastError()<<std::endl;
}
else{
std::cout<<"Good - Everything fine!\n"<<std::endl;
}
SOCKET u_sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
if(u_sock==INVALID_SOCKET)
std::cout<<"Creating socket fail\n";
else
std::cout<<"It was okay to create the socket\n";
//Socket address information
sockaddr_in addr;
addr.sin_family=AF_INET;
addr.sin_addr.s_addr=inet_addr("192.168.45.88");
addr.sin_port=htons(15000);
std::cout<<"Successfully provided the address"<<std::endl;
/*==========Addressing finished==========*/
//Now we connect
int conn=connect(u_sock,(SOCKADDR*)&addr,sizeof(addr));
std::cout<<"conn value:"<<conn<<std::endl;
if(conn==SOCKET_ERROR){
std::cout<<"Error - when connecting "<<WSAGetLastError()<<std::endl;
closesocket(u_sock);
WSACleanup();
}
std::cout<<"Successfully connected to server"<<std::endl;
//Send some message to remote host
char* mymsg="Hello Server...How are you?";
char vect[512]={0};
int smsg=send(u_sock,mymsg,sizeof(mymsg),0);
if(smsg==SOCKET_ERROR){
std::cout<<"Error: "<<WSAGetLastError()<<std::endl;
WSACleanup();
}
int get=recv(u_sock,vect,512,0);
if(get==SOCKET_ERROR){
std::cout<<"Error in Receiving: "<<WSAGetLastError()<<std::endl;
}
std::cout<<vect<<std::endl;
closesocket(u_sock);
getch();
return 0;
}
Java Server：
import java.net.*;
import java.io.*;
public class EchoServer {
public static void main(String[] args) throws IOException {
/* if (args.length != 1) {
System.err.println("Usage: java EchoServer <port number>");
System.exit(1);
}*/
int portNumber = 15000;
try (
ServerSocket serverSocket = new ServerSocket(portNumber);
Socket clientSocket = serverSocket.accept();
PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
) {
String inputLine;
while ((inputLine = in.readLine()) != null) {
System.out.println(inputLine);
out.println(inputLine);
}
} catch (IOException e) {
System.out.println("Exception caught when trying to listen on port "
+ portNumber + " or listening for a connection");
System.out.println(e.getMessage());
}
}
}
Java客户端：
import java.io.*;
import java.net.*;
public class EchoClient {
public static void main(String[] args) throws IOException {
if (args.length != 0) {
System.err.println(
"Usage: java EchoClient <host name> <port number>");
System.exit(1);
}
String hostName = "192.168.45.88";
int portNumber = 15000;
try (
Socket echoSocket = new Socket(hostName, portNumber);
PrintWriter out =
new PrintWriter(echoSocket.getOutputStream(), true);
BufferedReader in =
new BufferedReader(
new InputStreamReader(echoSocket.getInputStream()));
BufferedReader stdIn =
new BufferedReader(
new InputStreamReader(System.in))
) {
String userInput;
while ((userInput = stdIn.readLine()) != null) {
out.println(userInput);
System.out.println("echo: " + in.readLine());
}
} catch (UnknownHostException e) {
System.err.println("Don't know about host " + hostName);
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to " +
hostName);
System.exit(1);
}
}
}
答案 0 :(得分：1)
少数事情：
1）当使用winsock套接字发送数据时，sizeof（mymsg）是错误的，它应该是strlen（mymsg）+1
2）我之前编写过Java-Server-C ++ -Client，主要是处理ASCII与UNICODE。在Java端接收，确保它从ASCII字符构建字符串作为编码。另一方面，当向winsock服务器发送数据时 - 将其作为二进制数据发送，否则winsock服务器无法完成recv（）函数。
答案 1 :(得分：0)
好的。我会为此付出一些努力。有点令人耳目一新的事情。 ^^ 我修改了你的代码，因此使用了消息长度模式。 c客户端向服务器发送消息，java客户端对其进行解码并将其发送回客户端。因此，您既可以编码也可以运行编码方向。请尝试理解代码中发生的情况，否则您将再次遇到问题。 ByteOrder Stuff在java端完成，所以你可以摆弄你的封闭式C服务器。
C客户：
int main(int argc, char* argv[])
{
WSAData version; //We need to check the version.
WORD mkword=MAKEWORD(2,2);
int what=WSAStartup(mkword,&version);
if(what!=0){
std::cout<<"This version is not supported! - \n"<<WSAGetLastError()<<std::endl;
}
else{
std::cout<<"Good - Everything fine!\n"<<std::endl;
}
SOCKET u_sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
if(u_sock==INVALID_SOCKET)
std::cout<<"Creating socket fail\n";
else
std::cout<<"It was okay to create the socket\n";
//Socket address information
sockaddr_in addr;
addr.sin_family=AF_INET;
addr.sin_addr.s_addr=inet_addr("127.0.0.1");
addr.sin_port=htons(15000);
std::cout<<"Successfully provided the address"<<std::endl;
/*==========Addressing finished==========*/
//Now we connect
int conn=connect(u_sock,(SOCKADDR*)&addr,sizeof(addr));
std::cout<<"conn value:"<<conn<<std::endl;
if(conn==SOCKET_ERROR){
std::cout<<"Error - when connecting "<<WSAGetLastError()<<std::endl;
closesocket(u_sock);
WSACleanup();
}
std::cout<<"Successfully connected to server"<<std::endl;
//Send some message to remote host
char* mymsg="Hello Server...How are you?";
int length = strlen(mymsg);
//Cast the integer to char and send it
int smsg=send(u_sock,reinterpret_cast<char*>(&length), sizeof(int),0);
//Send the actual message
smsg=send(u_sock,mymsg,strlen(mymsg),0);
int newlength;
//Receive exactly 4 bytes for the length. If not the right length is received, repeat.
int get = 0;
while((get+=recv(u_sock,(reinterpret_cast<char*>(&newlength))+get,4,0)) < 4) {}
std::cout<<"Length: " << newlength << std::endl;
//Create new char array with newlength + 1 so we have a zero terminated string.
char* newMsg = new char[newlength+1];
memset(newMsg,0,newlength+1);
get = 0;
//Receive the string. If not the right length is received, repeat.
while((get+=recv(u_sock,newMsg+get,newlength,0)) < newlength) {}
std::cout<<"Message: " << newMsg << std::endl;
closesocket(u_sock);
int i;
std::cin >> i;
return 0;
}
Java Server：
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.#
int portNumber = 15000;
try (
ServerSocket serverSocket = new ServerSocket(portNumber);
Socket clientSocket = serverSocket.accept();
OutputStream os = clientSocket.getOutputStream();
PrintWriter out = new PrintWriter(os, true);
//BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
InputStream is = clientSocket.getInputStream();
) {
//RECV
//Create ByteBuffer for length integer
ByteBuffer bLength = ByteBuffer.allocate(4);
//C is usually Little_Endian
bLength.order(ByteOrder.LITTLE_ENDIAN);
//Read 4 bytes
is.read(bLength.array(), 0, 4);
//Convert the length
int length = bLength.getInt();
System.out.println("Length: "+length);
//Allocate ByteBuffer for message
ByteBuffer bMessage = ByteBuffer.allocate(length);
bMessage.order(ByteOrder.LITTLE_ENDIAN);
is.read(bMessage.array(), 0, length);
//Convert the message to string
String msg = new String( bMessage.array() );
System.out.println(msg);
//SEND
//Create ByteBuffer with length
ByteBuffer bLengthNew = ByteBuffer.allocate(4);
bLengthNew.order(ByteOrder.LITTLE_ENDIAN);
bLengthNew.putInt(msg.length());
//Write the length bytebuffer to the outputstream
os.write(bLengthNew.array());
//Write the message to the outputstream. (Don't use println)
out.print(msg);
//Flush it. (It automatically gets flushed on a \n, but we dont want that.
out.flush();
} catch (IOException e) {
System.out.println("Exception caught when trying to listen on port "
+ portNumber + " or listening for a connection");
System.out.println(e.getMessage());
}
}