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); //0 means get a free port

    int client_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (client_socket < 0)
    {
        printf("Create Socket Failed!
");
        exit(1);
    }
    //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!
");
        exit(1);
    }

    //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) == 0)
    {
        printf("Server IP Address Error! 
");
        exit(1);
    }
    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) < 0)
    {
        printf("Can Not Connect To localhost!
");
        exit(1);
    }else
         printf("connect successful! 
");
    std::string buffer;
    char buf[MAXDATA];
    bool flag = false;
    while(1){
        buffer = flag == true ? "13" : "10";
　　　　 if(write(client_socket,buffer.c_str(),buffer.length()) == -1)
        {
            perror("send error!");
            exit(1);
        }
        sleep(1);
        flag = !flag;
        if((recv(client_socket, buf, MAXDATA,0)) == -1)
                {
                    perror("receive error!");
                    exit(1);
                }

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