EOFException

I wanted to create a simple method that send a Serializable object/Object through a socket. But it wasnt as easy as I thought, I am getting exception and I dont know why.

The receiver (client)

Code:

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java.io.EOFException
        at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2298)
        at java.io.ObjectInputStream$BlockDataInputStream.readShort(ObjectInputStream.java:2767)
        at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:798)
        at java.io.ObjectInputStream.<init>(ObjectInputStream.java:298)
        at Client.receiveObject(Client.java:101)
        at Client.receiveFile(Client.java:60)
        at Client.receiveFile(Client.java:93)
        at Client.main(Client.java:26)
Exception in thread "main" java.lang.NullPointerException
        at Client.receiveFile(Client.java:60)
        at Client.receiveFile(Client.java:93)
        at Client.main(Client.java:26)

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Code:

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import java.io.*;
import java.net.*;
import java.text.*;
import java.util.*;

public class Client
{
        private static final int BUFFER_SIZE = 65536;
        static File[] files =
                {new File ("E:\\test1.txt"),
                new File  ("E:\\test2.txt"),
                new File  ("E:\\test3.txt")};

    public static void main(String[] args) throws Exception
    {
                enableDebugging ();//Ignore this

                System.out.println ("Client");
      Socket sock = null;

      try
      {
              sock =new Socket ("yrm0dder.no-ip.org", 40000);
                        System.out.println ("Connected");

              receiveFile(sock, files);
      }
      catch (IOException e)
      {
              e.printStackTrace();
      }
      finally
      {
              try {
                        sock.close ();
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }

      }
    }

        public static void receiveFile (Socket sock, File destination)
        {
                BufferedOutputStream fileOut = null;

                try
                {
                        //Receive data from socket
                        InputStream netIn = sock.getInputStream();

                        //Write bytes to a file
                        fileOut = new BufferedOutputStream (new FileOutputStream (destination));

                        byte[] buffer = new byte[BUFFER_SIZE];
                        int readBytes;

                        //Receive the file size
                        long fileSize = (Long) receiveObject (sock);
                        long counter = 0;
                        do
                        {
                                readBytes = netIn.read (buffer);
                                fileOut.write (buffer, 0, readBytes);
                        }
                        while ((counter += readBytes) < fileSize);
                }
                catch (IOException e)
                {
                        e.printStackTrace ();
                }
                finally
                {
                        if (fileOut != null)
                        {
                                try
                                {
                                        fileOut.close ();
                                }
                                catch (IOException e)
                                {
                                        e.printStackTrace();
                                }
                        }
                }
        }

        //Receive files via socket
        public static void receiveFile (Socket sock, File[] destination)
        {
                for (int i = 0; i < destination.length; i++)
                        receiveFile (sock, destination[i]);
        }

        public static Serializable receiveObject (final Socket sock)
        {
                Serializable obj = null;
                try
                {
                        ObjectInputStream objIn = new ObjectInputStream (sock.getInputStream());
                        obj = (Serializable) objIn.readObject();
                }
                catch (IOException | ClassNotFoundException e)
                {
                        e.printStackTrace ();
                }
                return obj;
        }

        public static void enableDebugging () //Never mind what this does
        {
                Date date = new Date ();
                DateFormat df = DateFormat.getDateInstance();
                String theDate = df.format(date);

                java.io.File file = new java.io.File ("debug " + theDate + ".log");

                try
                {
                        System.setErr (new java.io.PrintStream (new java.io.FileOutputStream (file)));
                }
                catch (FileNotFoundException e)
                {
                        e.printStackTrace();
                        System.exit (-1);
                }
        }
}

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The method receiveObject(and sendObject) actually works, I have tested them in a test class. But in this program, it cause EOFException. Why?

For starters make your sender flush its output stream.

kind regards,

Jos