Re: McKoi db error

[Geert Bevin <gbevin at uwyn dot com>]

Dman, attached the wrong version :-/ Take this one instead. Sorry for 
the confusion.

Geert Bevin wrote:
> I've attached a testcase of
> the bug.


--
Geert Bevin             Uwyn
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http://www.uwyn.com     1030 Brussels
gbevin at uwyn dot com         Tel & Fax +32 2 245 41 06

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import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

public class SerializationBug
{
	public static class Expr implements java.io.Serializable
	{
		static final long serialVersionUID = 6981261114471924028L;

		public Expr()
		{
		}

		/*
		 * if this method is commented out you get the error message
		 * 
		 * Exception in thread "main" java.lang.Error:
		 * IO Error: Unknown marker on stream: 0
		 * at SerializationBug.main(java.lang.String[]) (Unknown Source)
		 */
		private void writeObject(java.io.ObjectOutputStream out)
			throws IOException
		{
			out.defaultWriteObject();
		}

		private void readObject(ObjectInputStream in)
			throws IOException, ClassNotFoundException
		{
			in.defaultReadObject();
		}
	}

	public static class NodeType4 implements java.io.Serializable
	{
		static final long serialVersionUID = 7866310557831478639L;

		// this member variable needs to be there too, otherwise
		// the bug doesn't appear, not a single clue why
		private long id;

		public NodeType4()
		{
		}
	}

	public static class NodeType3 implements java.io.Serializable
	{
		static final long serialVersionUID = -108747827391465748L;
		private Object first;
		private Object second;

		public NodeType3(Object first, Object second)
		{
			this.first = first;
			this.second = second;
		}
	}

	public static class NodeType2 implements java.io.Serializable
	{
		static final long serialVersionUID = -7783166856668779902L;
		private Object first;
		private Object second;

		public NodeType2(Object first, Object second)
		{
			this.first = first;
			this.second = second;
		}
	}

	public static class NodeType1 implements java.io.Serializable
	{
		static final long serialVersionUID = 4133205808616807832L;
		
		private Object first;
		private Object second;
		private Object third;

		public NodeType1(Object first, Object second, Object third)
		{
			this.first = first;
			this.second = second;
			this.third = third;
		}
	}

	public static void main(String[] args)
	{
		System.out.println("testing");
		try
		{
			ByteArrayOutputStream byte_out = new ByteArrayOutputStream();
			ObjectOutputStream out = new ObjectOutputStream(byte_out);
			NodeType4 node6 = new NodeType4();
			NodeType3 node5 = new NodeType3(node6, null);
			NodeType4 node4 = new NodeType4();
			NodeType3 node3 = new NodeType3(node4, new Expr());
			NodeType2 node2 = new NodeType2(node3, node6);
			NodeType1 node1 = new NodeType1(node2, null, null);
			System.out.println("writing nodes");
			out.writeObject(node1);
			out.flush();
			out.close();
			out = null;
			System.out.println("reading nodes");
			byte[] buf = byte_out.toByteArray();
			ObjectInputStream in =
				new ObjectInputStream(new ByteArrayInputStream(buf));
			try
			{
				in.readObject();
			}
			catch (ClassNotFoundException e1)
			{
				e1.printStackTrace();
			}
		}
		catch (IOException e)
		{
			throw new Error("IO Error: " + e.getMessage());
		}
	}
}