Transfer binary file by byte array using TCP in java

Question

I am trying to transfer a binary file from the server to the client by blocks of bytes at a time. However, I am having a issue where it is stuck at transfering 8kb. The file is usually greater than a 1mb and the byte array is of size 1024. I believe it has to do something with my while loop since it doesnt close my connection. Any help? Thanks

Client

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

public class FileClient {

    public static void main(String[] argv) throws IOException {
        Socket sock = new Socket("localhost", 4444);
        InputStream is = null;
        FileOutputStream fos = null;

        byte[] mybytearray = new byte[1024];
        try {
            is = sock.getInputStream();
            fos = new FileOutputStream("myfile.pdf");

            int count;
            while ((count = is.read(mybytearray)) >= 0) {
                fos.write(mybytearray, 0, count);
            }
        } finally {
            fos.close();
            is.close();
            sock.close();
        }
    }
}

Server

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

public class FileServer {

    public static void main(String[] args) throws IOException {
        ServerSocket servsock = new ServerSocket(4444);
        File myFile = new File("myfile.pdf");
        FileInputStream fis = null;
        OutputStream os = null;
        while (true) {
            Socket sock = servsock.accept();
            try {
            byte[] mybytearray = new byte[1024];
            fis = new FileInputStream(myFile);
            os = sock.getOutputStream();

            int count;
            while ((count = fis.read(mybytearray)) >= 0) {
                os.write(mybytearray, 0, count);

            }
            os.flush();
            } finally {
            fis.close();
            os.close();
            sock.close();

            System.out.println("Socket closed");
            }
        }
    }
}

JB Nizet · Accepted Answer · 2012-02-06 08:09:56Z

3

Your loops should check for count >= 0 rather than count > 0, and the streams and the socket should be closed in a finally block. Other than that, the code looks fine to me.

What do you mean by "it is stuck at transfering 8kb"? Any exception occurring?

answered Feb 6, 2012 at 8:09

JB Nizet

694k94 gold badges1.3k silver badges1.3k bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Dan Over a year ago

I've changed the count and added a finally block but problem still exist. What I meant by stuck is that it doesnt reach the finally block. it copies and write only ~8kb of data and it just stalls

JB Nizet Over a year ago

The finally block should be out of the while loop. And you should make sure that each stream is closed by catching the IOException thrown by the close call itself. Which one stalls? the client or the server?

Collectives™ on Stack Overflow

Transfer binary file by byte array using TCP in java

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related