Client-Server: File transfer from Android to PC connected via socket And Response from server

Question

I am new in Java and Andriod. I have tried this example:

Client-Server: File transfer from Android to PC connected via socket

and it works perfectly. Now I want to reply from the server any message, and i can´t do it. Here is the code:

server side:

import java.io.*;
import java.net.*;

public class FileServer {

    public static void main(String[] args) throws IOException {
        int filesize=6022386; // filesize temporary hardcoded

        long start = System.currentTimeMillis();
        int bytesRead;
        int current = 0;

        // create socket
        ServerSocket servsock = new ServerSocket(1149);
        while (true) {
          System.out.println("Waiting...");

          Socket sock = servsock.accept();
          System.out.println("Accepted connection : " + sock);

       // receive file
            byte [] mybytearray  = new byte [filesize];
            InputStream is = sock.getInputStream();

            FileOutputStream fos = new FileOutputStream("C:\\Users\\Gustavo\\Desktop\\WebOffice.jpg"); // destination path and name of file
            BufferedOutputStream bos = new BufferedOutputStream(fos);
            bytesRead = is.read(mybytearray,0,mybytearray.length);
            current = bytesRead;

            // Recibe el File JPG
            do {
               bytesRead = is.read(mybytearray, current, (mybytearray.length-current));
               if(bytesRead >= 0) current += bytesRead;
            } while(bytesRead > -1);

            bos.write(mybytearray, 0 , current);
            bos.flush();
            long end = System.currentTimeMillis();
            System.out.println(end-start);
            bos.close();

            //RESPONSE FROM THE SERVER
            PrintWriter out = new PrintWriter(sock.getOutputStream(), true); 
            out.println(99); //REPLY DE NUMBER 99

            out.close();


          sock.close();
          }
    }   
}

client side:

package com.example.sclient;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class SendfileActivity extends Activity {
    /** Called when the activity is first created. */

    private static final int SELECT_PICTURE = 1;

    private String selectedImagePath;
    private ImageView img;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        System.out.println("34");
        img = (ImageView) findViewById(R.id.ivPic);
        System.out.println("36");
        ((Button) findViewById(R.id.bBrowse))
                .setOnClickListener(new OnClickListener() {
                    public void onClick(View arg0) {
                        System.out.println("40");
                        Intent intent = new Intent();
                        intent.setType("image/*");
                        intent.setAction(Intent.ACTION_GET_CONTENT);
                        startActivityForResult(
                                Intent.createChooser(intent, "Select Picture"),
                                SELECT_PICTURE);
                        System.out.println("47");
                    }
                });
        ;
        System.out.println("51");
        Button send = (Button) findViewById(R.id.bSend);
        final TextView status = (TextView) findViewById(R.id.tvStatus);

        send.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {

                Socket sock;
                try {
                    //sock = new Socket("MY_PCs_IP", 1149); 
                    sock = new Socket("192.168.0.12", 1149);
                    System.out.println("Connecting...");

                     // sendfile
                          File myFile = new File (selectedImagePath); 
                          byte [] mybytearray  = new byte [(int)myFile.length()];
                          FileInputStream fis = new FileInputStream(myFile);
                          BufferedInputStream bis = new BufferedInputStream(fis);
                          bis.read(mybytearray,0,mybytearray.length);
                          OutputStream os = sock.getOutputStream();
                          System.out.println("Sending...");
                          os.write(mybytearray,0,mybytearray.length);
                          os.flush();

                          //RESPONSE FROM THE SERVER
                          BufferedReader in = new BufferedReader(new InputStreamReader(sock.getInputStream()));
                          in.ready();
                          String userInput = in.readLine();
                          System.out.println("Response from server..." + userInput);

                        sock.close();
                } catch (UnknownHostException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }




            }
        });
    }
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK) {
            if (requestCode == SELECT_PICTURE) {
                Uri selectedImageUri = data.getData();
                selectedImagePath = getPath(selectedImageUri);
                TextView path = (TextView) findViewById(R.id.tvPath);
                path.setText("Image Path : " + selectedImagePath);
                img.setImageURI(selectedImageUri);
            }
        }
    }

    public String getPath(Uri uri) {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }
}

Explain can't do it. If theres an error , Please post it. – wtsang02 Jul 17 '13 at 14:42 — wtsang02, Jul 17 '13 at 14:42

ja_mesa · Answer 1 · 2013-07-17T21:16:26.967

Gustavo, The transfer is done well, but as long as the server don't know how much data you are sending it waits in the read loop until you close the socket or a timeout occurs. In order to let the server knows you have sent the whole data the socket must be shut down for output, with this, the server will received that indication, read() returns 0. Then the server will send the 99 message to the client.

For example:

at the server:

int ret=0;
int offset=0;
byte[] mybytearray = new byte[filesize];
while ((ret = is.read(mybytearray, offset, filesize -offset)) > 0)
{
    offset+=ret;
    // just in case the file is bigger that the buffer size
   if (offset >= filesize) break;
}
bos.write(mybytearray, 0 , offset);            
bos.flush();            
long end = System.currentTimeMillis();            
System.out.println(end-start);            
bos.close();
// RESPONSE FROM THE SERVER            
PrintWriter out = new PrintWriter(sock.getOutputStream(), true);            
out.println(99); //REPLY DE NUMBER 99
out.close();

at the client:

System.out.println("Sending...");
os.write(mybytearray,0,mybytearray.length);
os.flush();
// RESPONSE FROM THE SERVER 
BufferedReader in = new BufferedReader(new InputStreamReader(sock.getInputStream()));
in.ready(); 
// tell the receiver we are done sending
sock.shutdownOutput();
String userInput = in.readLine();                          
System.out.println("Response from server..." + userInput);

Thks for te reply. I´m going to try this next weekend. Thks Again! — Gustavo, Jul 18 '13 at 13:52
Enhancement for large files : USE: byte [] buffer= new byte[4096]; instead of byte [] mybytearray = new byte [(int)myFile.length()]; — MSaudi, Nov 02 '14 at 10:46

Client-Server: File transfer from Android to PC connected via socket And Response from server

1 Answers1