Android : Android client does not update the data when connect with linux socket

I have my android app connect to a linux HAC server (or HPC) implemented on C++ using sockets , but the problem that the android does not update the received message from the server! I have closed the process on the HAC server and every time I still receive the same text from the server! I don't even know how the application still fetching the data even if the process that runs the server is closed! Small scenario to what happens with me: I run the server I fetch any string from the server I close the server process (ctrl+c) I change the server to send the time instead of that old string I recompile it and run the server and still getting the old string instead of the time, even if there server is closed or open!

This is the android client :

withdraw.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
         MyClientTask myClientTask = new MyClientTask(
                 "1.1.1.1.", // removed for security reasons!
                   0000
                   );
                 myClientTask.execute();

    } // end of OnClick
}); // end of setOnClickListener
}



public class MyClientTask extends AsyncTask<Void, Void, Void> {   

  String dstAddress;
  int dstPort;
  String response = "";

  MyClientTask(String addr, int port){
   dstAddress = addr;
   dstPort = port;
  }

  @Override
  protected Void doInBackground(Void... arg0) {

   Socket socket = null;

   try {
    socket = new Socket(dstAddress, dstPort);

    ByteArrayOutputStream byteArrayOutputStream = 
                  new ByteArrayOutputStream(1024);
    byte[] buffer = new byte[1024];

    int bytesRead;
    inputStream = socket.getInputStream();

    /*
     * notice:
     * inputStream.read() will block if no data return
     */
             while ((bytesRead = inputStream.read(buffer)) != -1){
                 byteArrayOutputStream.write(buffer, 0, bytesRead);
                 response += byteArrayOutputStream.toString("UTF-8");
             }

   } catch (UnknownHostException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
    response = "UnknownHostException: " + e.toString();
   } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
    response = "IOException: " + e.toString();
   }finally{
    if(socket != null){
     try {
      socket.close();
      inputStream.close();
     } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
     }
    }
   }
   return null;
  }

  @Override
  protected void onPostExecute(Void result) {
   tv.setText(response);
   super.onPostExecute(result);
  }

 }

and this is the server

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

int main(int argc, char *argv[])
{
    int listenfd = 0, connfd = 0;
    struct sockaddr_in serv_addr; 

    char sendBuff[1025];
    time_t ticks; 

    listenfd = socket(AF_INET, SOCK_STREAM, 0);
    memset(&serv_addr, '0', sizeof(serv_addr));
    memset(sendBuff, '0', sizeof(sendBuff)); 

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(5000); 

    bind(listenfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)); 

    listen(listenfd, 10); 

    while(1)
    {
        connfd = accept(listenfd, (struct sockaddr*)NULL, NULL); 

        ticks = time(NULL);
        snprintf(sendBuff, sizeof(sendBuff), "%.24s\r\n", ctime(&ticks));
        write(connfd, sendBuff, strlen(sendBuff)); 

        close(connfd);
        sleep(1);
     }
}