grails - Send the zip content to response before you complete the zip creation -

i have successfully, on "local-build", been able create temp-folder , add image files inside of zipped , downloaded user. unfortunately after deploying test-server, unable create such temp folder , thusly cannot zip , stream it, believe, due permission errors. @ pass. cannot gain access create folders on test-server, , either need store folder , files on s3 bucket , create zipoutputstream here -or- think may better solution if possible, "on-the-fly" send zip content response before complete zip creation. possible? , if how go doing so? there benefit method on storing files temporarily on s3 zipped , streamed.

current code folder creation , zipping , streaming

def downloadzip(){      def fname = params.fname // zipfile name passed in 'example.zip'     def floc = params.floc   //folder location passed in '/example'     def user = user.get( floc long ) //get users files zipped                   def urllist = []      list ownedids      //create temporary directory place files inside before zipping     new file(floc).mkdir()      //dynamic resource 'http://example.com/' -or- 'http://localhost:8080/'     def location = "${resource( dir:'/', absolute:true )}"      //collect , download qr-codes image files     ownedids = user.geolinks.collect {         //define url download          def urls = (location+"qrcode/download?u=http%3a%2f%2fqr.ageoa.com%2f" +it.linkaddress+ "&s=150&n=" +it.linkaddress)                  //download each qr-code         download2(urls,floc)     }      //zip directory created , filled qr codes     string zipfilename = fname     string inputdir = floc      zipoutputstream zipfile = new zipoutputstream(new fileoutputstream(zipfilename))     new file(inputdir).eachfile() { file ->         zipfile.putnextentry(new zipentry(file.getname()))         def buffer = new byte[1024]         file.withinputstream { ->             def l = i.read(buffer)             // check whether file empty             if (l > 0) {                 zipfile.write(buffer, 0, l)             }         }         zipfile.closeentry()     }     zipfile.close()      //download qr-code zip-file     try {         def file = new file(fname)             response.setcontenttype("application/octet-stream")         response.setheader("content-disposition", "attachment;filename=${file.getname()}")         response.outputstream << file.newinputstream() // performing binary stream copy                                }            catch(exception e){             e.printstacktrace()     }         //delete temporary folder     def dir2 = new file(floc)     dir2.deletedir() }   //download qr-codes images folder [userid] def download2(address, dir){     def file = new fileoutputstream(dir+"/"+address.tokenize("&n=")[-1]+".png")     if(file){         def out = new bufferedoutputstream(file)         out << new url(address).openstream()         out.close()     } } 

right, should it, let me know if of doesn't make sense...

// list of things download , add zip list<url> testlist = [ 'http://cdn.sstatic.net/stackoverflow/img/sprites.png?v=6',                        'https://www.google.co.uk/images/srpr/logo4w.png' ]*.tourl() response.setheader( "content-disposition", "attachment; filename=resources.zip" ) response.contenttype = "application/octet-stream"  // wrap response stream in zipoutputstream new zipoutputstream( response.outputstream ).withstream { zos ->      // add root folder zip files, not spiteful     zos.putnextentry( new zipentry( "resources/" ) )      // each url     testlist.each { res ->          // name file in zip           // bit might tricky bit guess don't know file         // names. instead of might need check response         // object opening connection url.  however, without         // working example url you, can't sure :-(         string name = res.path.split( '/' )[ -1 ]          // create zip entry         zos.putnextentry( new zipentry( "resources/$name" ) )          // write resource stream our zip         res.withinputstream { ins ->             zos << ins         }          // close resource         zos.closeentry()      }     // close root folder     zos.closeentry() }