Transferring Multiple files using Java Sockets - Broken Pipe Exception

Question

I've been trying to write a client/server app that sends multiple files using Java sockets. I've looked through what seems like every thread pertaining to this and I just can't figure out why my code for sending the file is throwing a Broken Pipe exception when I write to the socket. I could really use some help; I've tried every method under the sun and I can't figure it out.

EDIT - Thanks, everyone! The code below works perfectly.

Sender code:

long size;

dos.writeInt(fileArray.length);

//send every file in array
for (File fileArray1 : fileArray) {
    int bytesRead = 0;

    fis = new FileInputStream(fileArray1);

    //send filename                        
    dos.writeUTF(fileArray1.getName());

    //send file size (bytes)
    dos.writeLong(size = fileArray1.length());

    System.out.println("Size: " + size);

    //send file 
    try {
        while ((bytesRead = fis.read(buf)) != -1) {
            dos.write(buf, 0, bytesRead);
            publish(new Progress(null, (int) ((sentByteCount / totalByteCount) * 100)));
        }

        dos.flush();

    } catch (IOException ex) {
    System.out.println("ERROR!!!!");
    }

    //close file stream, has been sent at this point
    fis.close();

}

System.out.println("Done sending files");
dos.close();
clientSocket.close();

Receiver Code:

while (true) {

    socket = serverSocket.accept();

    dis = new DataInputStream(new BufferedInputStream(socket.getInputStream()));

    //get number of files being received
    numFiles = dis.readInt();

    //read all files
    for (int i = 0; i < numFiles; i++) {

        filename = dis.readUTF();
        System.out.println("Receiving " + filename);

        size = dis.readLong();

        file = new File(filename);               

        fos = new FileOutputStream(filename);

        long total = 0;
        int count = 0;       

        while ((total < size) && ((count = dis.read(buf, 0, (int) Math.min(buf.length, size - total))) > 0)){
            fos.write(buf, 0, count);
            total += count;
        }

        fos.close();

        System.out.println("Received file " + filename);

    }


    dis.close();

}//end while

Answer 1

This line in the receiver has a return value which is important!

        dis.read(buf);

Most likely, you just want to use readFully() .

Also, you don't need to create a buffer for each read in the receiver, instead, using the multi-param read methods.

Answer 2

After the edit your write loop is still wrong. You're writing junk at the end of the file with this statement:

fos.write(buf);

A correct way to code that loop is as follows:

long total = 0;
while (total < size && (count = in.read(buffer, 0, size-total > buffer.length ? buffer.length : (int)(size-total))) > 0)
{
    fos.write(buffer, 0, count);
    total += count;
}
fos.close();

That way you don't write junk at the end of the file, and you don't need the DataInputStream either.

NB:

• Don't flush inside loops. It completely destroys the point of buffering.

• You don't need this:

   if (!file.exists()) file.createNewFile(); 

Calling new FileOutputStream() already does all that. You're just repeating work that the operating system already does, and it will still do it anyway.