C++ 服务端与 Java 客户端的简单连接

记录一下如何用两种语言简单通信，（其实也大差不差的，应该把。。。）

// C++ 服务端
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#include <iostream>
#include <cstring>

using std::cout;
using std::endl;
using std::string;

void Error(string msg) {
    cout << msg << " " << strerror(errno) << endl;
}

int main()
{
    cout << "---服务器启动---" << endl;
    int sock = socket(AF_INET, SOCK_STREAM, 0);
    sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = inet_addr("0.0.0.0");
    addr.sin_port = htons(26119);
    if (bind(sock, (sockaddr*)&addr, sizeof(addr)) == -1) {
        Error("绑定失败");
    }

    if (listen(sock, 255) == -1) {
        Error("监听失败");
    }

    int client = accept(sock, 0, 0);
    if (client == -1) {
        Error("接收失败");
    }
    char* buffer = new char;
    int len = recv(client, buffer, 0xff, 0);
    cout << "有客户端连接，接收数据为：" << buffer << ",长度: " << len <<  endl;

    cout << "发送数据" << endl;

    char* buff = "hello this is came form C++";
    send(client, buff, strlen(buffer), 0);


    close(sock);
    cout << "---服务端关闭---" << endl;
    return 0;
}

// Java 客户端
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class Test {
    public static void main(String[] args) {
        System.out.println("---客户端启动---");
        try{
            Socket socket = new Socket("120.24.177.154",26119);
            //使用PrintWriter和BufferedReader进行读写数据
            PrintWriter pw = new PrintWriter(socket.getOutputStream());
            BufferedReader is = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            
            //发送数据
            pw.println("hello, this's come from java socket");
            pw.flush();
            
//          //接收数据
            String line = is.readLine();//readLine必须有结尾，比如\n换行，否则会一直读下去，触发超时
            System.out.println("received from server " + line);
            
            //关闭资源
            pw.close();
            is.close();
            socket.close();
        }
        catch (Exception e){
            e.printStackTrace();
        }
        System.out.println("---客户端关闭---");
    }
}