DB mdb = this.mongoConn.getDatabase(this.collection);
GridFS gfsFile = new GridFS(mdb, this.namespace);
// get file file by it's filename
GridFSDBFile fileForOutput = null;
fileForOutput = gfsFile.findOne(id);
if (fileForOutput == null)
{
this.logger.error("[File][GridFS] Can not retrieve item: {}", id);
throw new IllegalStateException(id + " Item not found in Mongo database");
}