Exception in thread "main" java.net.SocketException: Connection reset -

I have created a simple Client/Server program where the client takes a file from command line arguments. The client then sends the file to the server, where it is compressed with GZIP and sent back to the client.

The server program when ran first is fine, and produces no errors but after running the client I get the error.

I am getting an error saying the connection is reset, and i've tried numerous different ports so i'm wondering if there is something wrong with my code or time at which i've closed the streams?

Any help would be greatly appreciated!

EDIT - Made changes to both programs.

Client:

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

//JZip Client

public class NetZip {

    //Declaring private variables.
    private Socket socket = null;
    private static String fileName = null;
    private File file = null;
    private File newFile = null;
    private DataInputStream fileIn = null;
    private DataInputStream dataIn = null;
    private DataOutputStream dataOut = null;
    private DataOutputStream fileOut = null;


    public static void main(String[] args) throws IOException {
    try {
        fileName = args[0];
        }
    catch (ArrayIndexOutOfBoundsException error) {
        System.out.println("Please Enter a Filename!");
    }
    NetZip x = new NetZip();
    x.toServer();
    x.fromServer();

    }

    public void toServer() throws IOException{
    while (true){
    //Creating socket
       socket = new Socket("localhost", 4567);
       file = new File(fileName);

       //Creating stream to read from file.
       fileIn = new DataInputStream(
           new BufferedInputStream(
               new FileInputStream(
                   file)));

       //Creating stream to write to socket.
       dataOut = new DataOutputStream(
           new BufferedOutputStream(
               socket.getOutputStream()));

       byte[] buffer = new byte[1024];

           int len;
           //While there is data to be read, write to socket.
        while((len = fileIn.read(buffer)) != -1){
            try{
            System.out.println("Attempting to Write " + file
                + "to server.");
            dataOut.write(buffer, 0, len);
            }
            catch(IOException e){
            System.out.println("Cannot Write File!");
            }
           } 
        fileIn.close();
        dataOut.flush();
        dataOut.close();

        }

    }
  //Read data from the serversocket, and write to new .gz file.
    public void fromServer() throws IOException{

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

    fileOut = new DataOutputStream(
           new BufferedOutputStream(
               new FileOutputStream(
                   newFile)));

    byte[] buffer = new byte[1024];

        int len;
        while((len = dataIn.read(buffer)) != -1){
            try {
            System.out.println("Attempting to retrieve file..");
            fileOut.write(buffer, 0, len);
            newFile = new File(file +".gz");

            }
            catch (IOException e ){
            System.out.println("Cannot Recieve File");
            }
        } 
        dataIn.close();
        fileOut.flush();
        fileOut.close();
        socket.close();

    }


}

Server:

import java.io.*;
import java.net.*;
import java.util.zip.GZIPOutputStream;

//JZip Server

public class ZipServer {

    private ServerSocket serverSock = null;
    private Socket socket = null;
    private DataOutputStream zipOut = null;
    private DataInputStream dataIn = null;

    public void zipOut() throws IOException {

    //Creating server socket, and accepting from other sockets.
    try{
    serverSock = new ServerSocket(4567);
    socket = serverSock.accept();
    }
    catch(IOException error){
        System.out.println("Error! Cannot create socket on port");
    }

    //Reading Data from socket
    dataIn = new DataInputStream(
           new BufferedInputStream(
                   socket.getInputStream()));

    //Creating output stream.
    zipOut= new DataOutputStream(
        new BufferedOutputStream(
            new GZIPOutputStream(
                socket.getOutputStream())));

    byte[] buffer = new byte[1024];

        int len;
        //While there is data to be read, write to socket.
        while((len = dataIn.read(buffer)) != -1){
            System.out.println("Attempting to Compress " + dataIn
                + "and send to client");
            zipOut.write(buffer, 0, len);
        } 
        dataIn.close();
        zipOut.flush();
        zipOut.close(); 
        serverSock.close();
        socket.close();
    }

    public static void main(String[] args) throws IOException{
    ZipServer run = new ZipServer();
    run.zipOut();

    }

}

Error Message:

Exception in thread "main" java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(SocketInputStream.java:196)
    at java.net.SocketInputStream.read(SocketInputStream.java:122)
    at java.io.BufferedInputStream.fill(BufferedInputStream.java:235)
    at java.io.BufferedInputStream.read1(BufferedInputStream.java:275)
    at java.io.BufferedInputStream.read(BufferedInputStream.java:334)
    at java.io.DataInputStream.read(DataInputStream.java:100)
    at ZipServer.<init>(ZipServer.java:38)
    at ZipServer.main(ZipServer.java:49)