Basic Java Fileserver

Question

I am trying to create a very barebones fileserver that does nothing more than download a zip file and exit, but I am running into problems. I have two main problems.

The first is that when I test on localhost, it sort of works, in that it transfers the zip file, but when I try to open it, I get an error about it being corrupt. It may be something to do with the zip file format, or how I am transferring it.

The second problem is that it fails whenever I use anything but localhost. I have tried a website redirect to my IP, and just putting in my ip address, and both fail, even when I turn off all firewalls and antivirus.

Server code:

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

public class FileServer {
    public static void main(String[] args) throws IOException {
    final int PORT_NUMBER = 44444;
    ServerSocket serverSock = null;
    PrintWriter out = null;
    BufferedInputStream bin = null;
    OutputStream os = null;
    Socket clientSock = null;
    File file;
    byte[] fileData;
    String filename = "file.zip";

    while(true) {
        try {
        //Listen on port
        serverSock = new ServerSocket(PORT_NUMBER);

        //Get connection
        clientSock = serverSock.accept();
        System.out.println("Connected client");

        //Get output stream
        out = new PrintWriter(clientSock.getOutputStream(), true);

        out.println(filename);    //Print filename
        file = new File(filename); //Get file
        fileData = new byte[(int)file.length()]; //Stores the file data
        bin = new BufferedInputStream(new FileInputStream(file));
        out.println((int)file.length()); //Print filesize
        bin.read(fileData); //Read contents of file
        os = clientSock.getOutputStream();
        os.write(fileData); //Write the file data
        os.flush();
        } catch(SocketException e) {
        System.out.println("Client disconnected");
        } catch(Exception e) {
        System.out.println(e.getMessage());
        System.exit(1);
        } finally {
        //Close all connections
        System.out.println("Shutting down");

        if(os != null) {
            os.close();
        }

        if(bin != null) {
            bin.close();
        }

        if(out != null) {
            out.close();
        }

        if(clientSock != null) {
            clientSock.close();
        }

        if(serverSock != null) {
            serverSock.close();
        }
        }
    }
    }
}

Client code snippet, assume that all syntax is correct and everything else exists and works, because I probably mismatched some braces or something when I cut the snippet out.

import java.io.*;
import java.net.*;
import javax.swing.JOptionPane;

public static void main(String[] args) {
        final int PORT_NUMBER = 44444;
        final String HOSTNAME = "127.0.0.1";
        String filename = "default.txt";
        Socket sock = null;
        BufferedReader in = null;
        BufferedOutputStream bos = null;
        InputStream is = null;
        byte[] fileData;

        //Attempt to connect
        try {
        sock = new Socket(HOSTNAME, PORT_NUMBER);
        in = new BufferedReader(new InputStreamReader(sock.getInputStream()));
        is = sock.getInputStream();
        } catch(UnknownHostException e) {
        JOptionPane.showMessageDialog(this, "Error: could not connect to host " + HOSTNAME + " on port number " + PORT_NUMBER);
        System.exit(1);
        } catch(ConnectException e) {
        JOptionPane.showMessageDialog(this, "Error: connection refused");
        System.exit(1);
        } catch(Exception e) {
        JOptionPane.showMessageDialog(this, e);
        System.exit(1);
        }

        try {
        filename = in.readLine();
        bos = new BufferedOutputStream(new FileOutputStream(filename));
        fileData = new byte[Integer.decode(in.readLine())]; //Gets file size
        is.read(fileData);
        bos.write(fileData);
        bos.flush();
        bos.close();

        if(is != null) {
            is.close();
        }

        if(in != null) {
            in.close();
        }

        if(bos != null) {
            bos.close();
        }

        if(sock != null) {
            sock.close();
        }
        } catch(Exception e) {
        JOptionPane.showMessageDialog(this, e);
        System.exit(1);
        }

        JOptionPane.showMessageDialog(this, "Download complete");
    }
    }
    }                                        

}

EDIT: It works just fine on localhost with .doc and .docx files, it is only .zip that causes problems.