EOFException

[Pojahn_M]

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)

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)

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);
		}
	}
}

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

[JosAH]

For starters make your sender flush its output stream.

kind regards,

Jos