mysql - grails - Downloading PDF getting empty file -

i'm storing files within mysql database. corresponding domain class looks follows:

import org.springframework.web.multipart.commons.commonsmultipartfile import grails.persistence.entity  @entity class document extends baseclass {      string documentreference     commonsmultipartfile cmffile      static constraints = {         documentreference nullable: true, maxsize: 500     }      static mapping = {         cmffile sqltype: "mediumblob"     } } 

i managed store different files within table in database. want enable user download of these files using following action:

def download(document documentinstance) {     if (documentinstance == null) {         notfound()         return     }      response.setcontenttype(documentinstance?.cmffile?.contenttype)     response.setheader("content-disposition", "attachment;filename=${documentinstance?.cmffile?.originalfilename}")     response.outputstream << documentinstance?.cmffile?.getbytes()     response.outputstream.flush()     return true  } 

my problem downloading works fine .docx, textfiles or images. however, when i'm trying download e.g. .pdf or .zip files empty. don't know difference i'm passing on content type.

i greatful help! thank you!

i use grails (2.3.11) , store files in mysql , works charm.

the differences can see are:

domain

i use blob type instead of commonsmultipartfile , type: 'blob' instead of sqltype: 'mediumblob'. set value such field can use new javax.sql.rowset.serial.serialblob(byte[]).

controller

i use (adjusted naming):

response.setcontenttype(servletcontext.getmimetype(documentinstance?.cmffile?.originalfilename)) response.setheader("content-disposition", "inline;filename=${documentinstance?.cmffile?.originalfilename}") response.outputstream << documentinstance?.cmffile?.getbytes() 

no flush(), no return true.

notes

i noticed use quite small maxsize constraint. 500 b not much. sure it's enough pdfs or zips?

besides, sure documentinstance?.cmffile not null?