java - 无法使用 Socket 连接将数据发送到 c 服务器

Question

这是我的 C 代码。它正在接收客户端发送的数据，并向客户端发送hello。

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include<errno.h>
#include<arpa/inet.h>

#define PORT 6865
#define BUF 1024

int main(int argc, char *argv[])
{
    struct sockaddr_in host, remote;
    int host_fd, remote_fd;
    int size = sizeof(struct sockaddr);;
    int read_t;
    char send_t[]="hello";
    char data[BUF];

    host.sin_family = AF_INET;
    host.sin_addr.s_addr = htonl(INADDR_ANY);
    host.sin_port = htons(PORT);
    memset(&host.sin_zero, 0, sizeof(host.sin_zero));

    host_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(host_fd == -1) 
    {
        printf("socket error %d\n", host_fd);
        return 1;
    }

    if(bind(host_fd, (struct sockaddr *)&host, size)) 
    {
        perror("bind error is\n");
        printf("errorno is %d\n",errno);
        return 1;
    }

    if(listen(host_fd, 5)) 
    {

        printf("listen error");
        return 1;
    }

    printf("Server setup, waiting for connection...\n");
    remote_fd = accept(host_fd, (struct sockaddr *)&remote, &size);

    printf("connection made\n");

    read_t = recv(remote_fd,data,sizeof(data),0);

    data[read_t]='\0';
    printf("read = %d, data = %s\n", read_t, data);
    if(send(remote_fd,send_t,sizeof(send_t),0)==-1)
    {
        printf("error in sending back\n");
        return 1;
    }
    //memset(data[BUF],0,sizeof(data));
    //read_t = recv(remote_fd,data,sizeof(data),0);
    //data[read_t]='\0';
    //printf("read = %d, received_data = %s \n", sizeof(data), data);
    shutdown(remote_fd, SHUT_RDWR);
    close(remote_fd);

    return 0;
}

这是客户端java代码。

package pack.client;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class Client 
{
    public static void main(String[] args) throws UnknownHostException, IOException 
    {
        char[] data = new char[10];
        OutputStreamWriter outs = null;
        InputStreamReader ins= null;

        Socket s = new Socket("10.9.79.80", 6865);
        outs = new OutputStreamWriter(s.getOutputStream());
        outs.append("Socket communication");

        ins= new  InputStreamReader(s.getInputStream());
        int da = ins.read(data, 0, 9);
        System.out.print(data);

        outs.close();
        ins.close();
        s.close();
    }
}

当客户端与服务器建立连接时，我可以在终端上看到已建立连接的消息，但服务器没有接收到数据。

Answer 1

写入服务器后需要刷新输出流。

    outs.append("Socket communication");
// or try this outs.write("Socket communication");
    outs.flush();