socket必须在客户端断开连接之后，服务器端才能接收到数据解决方案

socket必须在客户端断开连接之后，服务器端才能接收到数据
android手机为服务器端，PC端软件为客户端
PC客户端通过socket发送数据给服务器端，服务器端一直接收不到数据，只有当PC客户端断开socket连接之后，
手机服务器端才接收到数据，请问是怎么回事？怎么处理，谢谢
代码如下：
android 手机端linux(server)

int make_server_socket()
{
  int sockfd = socket(PF_INET, SOCK_STREAM, 0);
  struct sockaddr_in my_addr;
  memset(&my_addr, 0, sizeof(my_addr));
  my_addr.sin_family = AF_INET;
  my_addr.sin_port = htons(LISTENPORT);
  my_addr.sin_addr.s_addr = INADDR_ANY;

  if(sockfd>0)
  {
  int on = 1;
  setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
  if(bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr))==0)
  {
  if(listen(sockfd, 0)==0)
  {
  // No error
  }
  else
  {
  close(sockfd);
  sockfd = -3;
  }
  }
  else
  {
  close(sockfd);
  sockfd = -2;
  }
  }

  return sockfd;
}

int accept_socket(int sockfd)
{
  // Block until connections
  struct sockaddr_in peer_addr;
  unsigned int sin_size = sizeof(peer_addr);
  int new_fd = accept(sockfd, (struct sockaddr *)&peer_addr, &sin_size);
  return new_fd;
}

int recv_socket(int sockfd, void* buffer, int size)
{
int received = 0;

while (buffer && received < size)
{
int result = recv(sockfd, buffer + received, size - received, MSG_NOSIGNAL);
if (result > 0)
{
received += result;
}
else
{
received = result;
break;
}
}
return received;
}
.............
  while (1)
  {
  listenfd = make_server_socket();
memset(receive_buffer,0,sizeof(receive_buffer));
  if (listenfd > 0)
  {
  while (1)
  {

  tcpipfd = accept_socket(listenfd);
   
  if (tcpipfd > 0)
  {
  len=recv_socket(tcpipfd, recmsg, BUF_LEN_1024);
  }
  else
  {
  break;
  }
sleep(1);
  }
  close_socket(listenfd);
  }
  sleep(2);
  }
............


java客户端：

  byte[] bs = new byte[] { (byte) 127, (byte) 0, 0, 1 };
  InetAddress addr = InetAddress.getByAddress(bs);
  pcsocket =new Socket(addr,port);

  sender=new BufferedOutputStream(pcsocket.getOutputStream(),20);
  receiver=new BufferedInputStream(pcsocket.getInputStream(),20);

  sender.write(data.getBytes(),0,data.length());
  sender.write('n');
  sender.flush();

------解决方案--------------------
你这个是JAVA层的SOCKET通信？