public interface DatabaseSpecificUtils
{
  public int setBlobParameter( PreparedStatement statement, int index, Blob blob ) throws SQLException;
  public void setBlobParameterCleanup( int blobWriteId );
}

public class MyDatabaseUtils
{
   public static constant DatabaseSpecificUtils DATABASE_SPECIFIC_UTILS;
    
   static
   {
      boolean UseOracle;
      boolean UsePostgres;
    
      /* read config file to find out which database is going to be used */
      ...
    
      /* assign correct class to util constant */
      if (UseOracle)
        DATABASE_SPECIFIC_UTILS = new OracleDatabaseSpecificUtils();
      else if (UsePostgres)
        DATABASE_SPECIFIC_UTILS = new PostgresDatabaseSpecificUtils();
      else if (...)
        DATABASE_SPECIFIC_UTILS = new ...DatabaseSpecificUtils();
      ...
   }
}

   int blobWriteId = -1;
   try
   {
     PreparedStatement blobWriteStmt = dbConnection.prepareStatement( SQL_STMT );
     ...
     blobWriteId = MyDatabaseUtils.DATABASE_SPECIFIC_UTILS.setBlobParameter( blobWriteStmt, 1, myBlob );
     ...
     blobWriteStmt.executeUpdate();
   }
   catch (SQLException sqlEx)
   {
      ...
   }
   finally
   {
     MyDatabaseUtils.DATABASE_SPECIFIC_UTILS.setBlobParameterCleanup( blobWriteId );
   }