Java Database Connectivity (JDBC)

Hello every one,
I have gone thro the forums, and also the oracle sample programs, everything deal with uploading a .bmp file or .gif file or something in to a blob and retrieving it. I have a question in mind, whether the same can be achieved for uploading java objects. so, I uploaded a Hashtable, successfully i guess, using the following java program

import java.sql.*;
import oracle.sql.*;
import java.io.*;
import java.util.*;
import oracle.jdbc.*;

public class writeHashtable{
	public static void main(String [] args)
	throws IOException{
		
		Connection con = null;
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		BLOB blob = null;
		
		String selectforupdate = "select myblob from createBLOB where count = ? ";
		
		Hashtable ht = new Hashtable();
		ht.put("java","Storing a Hashtable in a blob");
		
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		ObjectOutput out = new ObjectOutputStream(outStream);
		out.writeObject(ht);
		ByteArrayInputStream inStream = new ByteArrayInputStream(outStream.toByteArray());
		
		try{
			Class.forName("oracle.jdbc.driver.OracleDriver");
		}catch(java.lang.ClassNotFoundException e){
			e.printStackTrace();
		}
		
		try{
			con = DriverManager.getConnection("jdbc:oracle:thin:scott/tiger@localhost:1521:concord4j");
			con.setAutoCommit(false);
			pstmt = con.prepareStatement("insert into calendar values('scott',empty_blob())");
			pstmt.executeUpdate();
			
			pstmt = con.prepareStatement(selectforupdate);
			pstmt.setString(1,"scott");
			
			rs = pstmt.executeQuery();
			
			while(rs.next()){
				blob = ((OracleResultSet)rs).getBLOB(1);
			}
			
			
			OutputStream os = blob.getBinaryOutputStream();
			int chunk = blob.getChunkSize();
			
			byte[] vectorBuffer = new byte[chunk];
			int length = -1;
			while ((length = inStream.read()) != -1) {
				os.write(length);
			}
			
			
		}catch(SQLException esql){
			esql.printStackTrace();
		}
	}
}

But the problem comes when i try to retrieve it,
Here is the code, i use for retrieving it.

import java.sql.*;
import oracle.sql.*;
import java.io.*;
import java.util.*;
import oracle.jdbc.*;

public class readHashtable{
	public static void main(String [] args)
	throws Exception{
		
		Connection con = null;
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		BLOB blob = null;
		
		String selectforupdate = "select myblob from createBLOB where count = ? ";
		
		
		try{
			Class.forName("oracle.jdbc.driver.OracleDriver");
		}catch(java.lang.ClassNotFoundException e){
			e.printStackTrace();
		}
		
		try{
			con = DriverManager.getConnection("jdbc:oracle:thin:scott/tiger@localhost:1521:concord4j");
			
			pstmt = con.prepareStatement(selectforupdate);
			pstmt.setString(1,"scott");
			
			rs = pstmt.executeQuery();
			
			while(rs.next()){
				blob = ((OracleResultSet)rs).getBLOB(1);
			}
			
			
			InputStream is = (InputStream)blob.binaryStreamValue();
			int chunk = blob.getChunkSize();
			System.out.println(chunk);
		
			ObjectInputStream in = new ObjectInputStream(is);
			
			Hashtable ht = (Hashtable)in.readObject(); // Exception at this line
			
			System.out.println(ht.get("java").toString());
		}catch(SQLException esql){
			esql.printStackTrace();
		}
	}
}

But i get an exception saying that

Exception in thread "main" java.io.EOFException: Expecting code
at java.io.ObjectInputStream.peekCode(ObjectInputStream.java:1551)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:292)
at java.io.ObjectInputStream.inputArray(ObjectInputStream.java:1142)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:374)
at java.io.ObjectInputStream.inputClassFields(ObjectInputStream.java:226
2)
at java.io.ObjectInputStream.defaultReadObject(ObjectInputStream.java:51
9)
at java.io.ObjectInputStream.inputObject(ObjectInputStream.java:1411)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:386)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:236)
at readBLob.main(readHashtable.java:44)

I am frustrated over this, trying to figure out what i am doing wrong. but i couldn't get any clue. so, i really appreciate, your help on this.
Thank you
concord4j