code: public Object getLobFromGFSEntity(GridFS gfs, EntityMetadata m, Object entity, KunderaMetadata kunderaMetadata)
      {
          MetamodelImpl metaModel = (MetamodelImpl) kunderaMetadata.getApplicationMetadata()
                  .getMetamodel(m.getPersistenceUnit());
          EntityType entityType = metaModel.entity(m.getEntityClazz());
          Set<Attribute> columns = entityType.getAttributes();
          for (Attribute column : columns)
          {
              boolean isLob = ((Field) column.getJavaMember()).getAnnotation(Lob.class) != null;
              if (isLob)
              {
                  return PropertyAccessorHelper.getObject(entity, (Field) column.getJavaMember());
              }
          }
          return null;
      }
docs: Gets the lob from GFS entity.
  
  @param gfs
  the gfs
  @param m
  the m
  @param entity
  the entity
  @param kunderaMetadata
  the kundera metadata
  @return the lob from gfs entity