[Pljava-dev] How to read LargeObject with pljava?

Hi everybody!

Have some code to read LargeObject from db and create digest message for
the it content. The code generate an error attemtting to read a portion
of LO.

Could anybody give an example how to read LO from database?

I'm using jre1.6.0.13, pljava1.4.0, postgresql8.3.7.

Thanks.

import java.io.FileOutputStream;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.logging.Logger;
import org.postgresql.largeobject.LargeObject;
import org.postgresql.largeobject.LargeObjectManager;

public class ServerDigestCreator {

public static String
anotherCreateStrDigest(org.postgresql.pljava.internal.Oid lObjectId)
throws SQLException,NoSuchAlgorithmException
{
String digest = null;
java.sql.Savepoint sp = null;
if(lObjectId==null) return null;
java.sql.Connection aConnection =
DriverManager.getConnection("jdbc:default:connection");
try{

sp = aConnection.setSavepoint();
org.postgresql.pljava.internal.LargeObject lo =
org.postgresql.pljava.internal.LargeObject.open(lObjectId,
org.postgresql.pljava.internal.LargeObject.INV_READ);

MessageDigest aDigest = MessageDigest.getInstance("md5");

if(lo==null) {
aConnection.releaseSavepoint(sp);
return digest;
}
byte buf[] = new byte[2048];
int s=0;

while((s = lo.read(buf))!=0)
<---------------------- Error occurs here
=============================================================
aDigest.update(buf);

byte[] digestByteArray = aDigest.digest();
BigInteger tempBI = new BigInteger(digestByteArray);
digest = tempBI.toString();
lo.close();

aConnection.releaseSavepoint(sp);
}
catch(SQLException ex)
{
if(sp!=null)
aConnection.rollback(sp);
Logger.getAnonymousLogger().info("ERROR: " + ex.getMessage()
+ "\n");
throw new SQLException(ex.getMessage());
}

return digest;
}