C++做client Java做客户端传送数据

因为要用到，但发现Java怎么都收不到C发来的数据，除非C端自动挂掉，java会一口气全收回来。

后来才发现是因为C发过来的Java用readline是读不到回车的，所以会一直等待。

所以不要用readline（），这是不正确滴。

具体应该如下：

Java Server端：

 package jsi;

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

 public class MyServer {

     public ServerSocket server;

     public MyServer(){
         new Thread(new Runnable(){
             private ServerSocket server;

             @Override
             public void run(){
                 try {
                     server = new ServerSocket(31003);
                     Socket socket = server.accept();
                     BufferedReader read = new BufferedReader(new
                             InputStreamReader(socket.getInputStream()));
                     PrintWriter print = new PrintWriter(socket.getOutputStream());
                     while(true){
                         char[] cbuf = new char[70];
                         read.read(cbuf);   // don't use : String msg = read.readline();
                         String msg = new String(cbuf);
                         if(msg.equals("bye")){
                             break;
                         }
                         print.write("OK");
                         print.flush();
                         double mm = Double.parseDouble(msg);
                         System.out.println(mm);

                     }
                 } catch (IOException e) {
                     // TODO Auto-generated catch block
                     e.printStackTrace();
                 }
             }

         }).start();
     }
     /**
      * @param args
      */
     public static void main(String[] args) {
         // TODO Auto-generated method stub
         new MyServer();
     }

 }

C++客户端：

/*
 * Client.cpp
 *
 *  Created on: 2013-11-29
 *      Author: root
 */

#include <errno.h>
#include <netinet/in.h>    // for sockaddr_in
#include <sys/types.h>    // for socket
#include <sys/socket.h>    // for socket
#include <stdio.h>        // for printf
#include <stdlib.h>        // for exit
#include <string.h>        // for bzero
#include <arpa/inet.h>
#include <unistd.h>
#include <string>
#define SERVER_PORT 31003
#define MAXDATA 50
int main(int argc, char **argv)
{
    struct sockaddr_in client_addr;
    bzero(&client_addr, sizeof(client_addr)); //set zero of this memory
    client_addr.sin_family = AF_INET; //internet protocol
    client_addr.sin_addr.s_addr = htons(INADDR_ANY); //INADDR_ANY means get the local address
    client_addr.sin_port = htons(); //0 means get a free port

    int client_socket = socket(AF_INET, SOCK_STREAM, );
    if (client_socket < )
    {
        printf("Create Socket Failed!\n");
        exit();
    }
    //bind the socket and ip address of the client machine
    if (bind(client_socket, (struct sockaddr*) &client_addr,
            sizeof(client_addr)))
    {
        printf("Client Bind Port Failed!\n");
        exit();
    }

    //socket struct had the server_addr and server port
    struct sockaddr_in server_addr;
    bzero(&server_addr, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    if (inet_aton("127.0.0.1", &server_addr.sin_addr) == )
    {
        printf("Server IP Address Error! \n");
        exit();
    }
    server_addr.sin_port = htons(SERVER_PORT);
    socklen_t server_addr_length = sizeof(server_addr);
    if (connect(client_socket, (struct sockaddr*) &server_addr,
            server_addr_length) < )
    {
        printf("Can Not Connect To localhost!\n");
        exit();
    }else
         printf("connect successful! \n");
    std::string buffer;
    char buf[MAXDATA];
    bool flag = false;
    while(){
        buffer = flag == true ? "" : "";
　　　　 if(write(client_socket,buffer.c_str(),buffer.length()) == -)
        {
            perror("send error!");
            exit();
        }
        sleep();
        flag = !flag;
        if((recv(client_socket, buf, MAXDATA,)) == -)
                {
                    perror("receive error!");
                    exit();
                }

                        printf("Received: %s\n",buf);
    }
}