Hi,

I am trying to save Blob data using ByteArrayInputStream instead of byte[]
as in BinaryBlobType example in http://www.hibernate.org/73.html.

My BinaryBlobType code as following:

<Code>
package sample;

import java.io.ByteArrayInputStream;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import java.sql.Blob;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.UserType;

public class BinaryBlobType implements UserType
{
public int[] sqlTypes()
{
return new int[] { Types.BLOB };
}

public Class returnedClass()
{
//return byte[].class;
return ByteArrayInputStream.class;
}

public boolean equals(Object x, Object y)
{
//ByteArrayInputStream x = (ByteArrayInputStream)a;
//ByteArrayInputStream y = (ByteArrayInputStream)b;

return (x == y) //ClassCastException here ************
|| (x != null
&& y != null
&& java.util.Arrays.equals((byte[]) x, (byte[]) y));
}

public Object nullSafeGet(ResultSet rs, String[] names, Object owner)
throws HibernateException, SQLException
{
Blob blob = rs.getBlob(names[0]);
//return blob.getBytes(1, (int) blob.length());
return (ByteArrayInputStream) blob.getBinaryStream();
}

public void nullSafeSet(PreparedStatement st, Object value, int index)
throws HibernateException, SQLException
{
//st.setBlob(index, Hibernate.createBlob((byte[]) value));
final byte[] buf = (byte[]) value;
ByteArrayInputStream in = new ByteArrayInputStream(buf);
st.setBinaryStream(index, in, buf.length);
}

public Object deepCopy(Object value)
{
if (value == null) return null;

//byte[] bytes = (byte[]) value;
//byte[] result = new byte[bytes.length];
//System.arraycopy(bytes, 0, result, 0, bytes.length);
final byte[] buf = (byte[]) value;
ByteArrayInputStream result = new ByteArrayInputStream(buf);

return result;
}

public boolean isMutable()
{
return true;
}

}

</Code>

Then I set type = "sample.BinaryBlobType". I have tried numerous ways to transform the above code from using byte[] to ByteArrayInputStream.
But I keep getting ClassCastException inside equals method. I am wondering if it is feasible to use ByteArrayInputStream to do the job (and to improve performance)?

regards,

Not sure if this is do to bad copy/paste, but your UserType is defining the returned class as type ByteArrayInputStream, but then in the equals() above it tries to cast the ByteArrayInputStream params to byte[] in java.util.Arrays.equals((byte[]) x, (byte[]) y).

First note, you can simply use x.equals(y), which ByteArrayInputStreams inherit from Object.

Secondly, here's a bit of code that you could use to convert to a String and back again.



-G

Thanks, guys for your input:

for the following method:



from API:
names - the column names

so:

names[0] means the first column ? This should be the table column storing Blob, right? For example, in my db, if my Blob data is stored in column 6, the I should use :

Blob blob = rs.getBlob(names[6]);

Is that right?

I tried the above, but it gave me "java.lang.ArrayIndexOutOfBoundsException: 6"

regards,[/code]

The names array only "covers" columns spanned by your type. If you only map one column using this type, then the names array will be length of one...

Oh, and the sixth element in a zero-based array would be index 5

:)