java - Efficient way to expose generated files in the server? -


i'm working on application running on jboss5.1, jee5, jsf2, spring3.0, icefaces2.0, html , jquery1.8.

i have requirement of generating files on fly customers download. when file generated, i'm streaming file content bytes on jsf page , using <ice:outputresource> show link download. works fine smaller size files. file size increases, not solution i'm running outofmemoryerror issues because application jvm has bear burden of taking file content heap , funnel through application.

what provide generated files direct links can served web contained through http. have constraint of doing in secure environment user authenticated before can generate , see link. so, plan generate file web-inf directory , delete file user downloads, making web-inf contain files being viewed customers. i'm not sure how jboss server handles these files in terms of caching , if affects server performance. also, appreciate if there alternative approaches problem.

i believe described problem clearly, if not please let me know. in advance time , assistance.

ps - can create files outside web-inf , still make them secure.

  • use preconfigured folder outside webapp on server. mentioned earlier in comments, not idea generate them inside web-inf
  • create servlet serve content of requested file user preconfigured folder
  • you can protect servlet if needed
  • the servlet can delete file delivered user
  • alternatively, can map external folder webapp , let jboss serve them static content (but need protect access if required)

p.s. may still "scheduled" cleanup in case generated file never downloaded.

servlet serving content (answer comment)

i not see problems security when having external folder in case. external folder accessible in application.

let's have directory generate files (filesrootdir) - /var/myapp/storage/tmp.

  1. create servlet in webapp knows location of filesrootdir
  2. let's servlet mapped following url (/mywebapp/downloads/file)
  3. to keep simple servlet receives parameter relative path generated file (path)
  4. taking above
    1. the app generates file here /var/myapp/storage/tmp/dir1/document.csv
    2. and generates link /mywebapp/downloads/file?path=/dir1/document.csv, user can download file
  5. when user decides download file, request handled servlet.
    1. the servlet receives location of requested file - /dir1/document.csv
    2. constructs absolute path concatenating filesrootdir , path parameter - /var/myapp/storage/tmp/dir1/document.csv
    3. reads , outputs content of file user

i believe can apply same security constraints servlet have in app, because part of application.


Comments

Post a Comment

Popular posts from this blog

Why does Ruby on Rails generate add a blank line to the end of a file? -

running rails generate controller foo home results in: class foocontroller < application controller def home end end (there's nothing on line in actual file, blank line) is there purpose blank line? it's common use newline indicate end of line, last line. many editors (like vi, use) add in newline silently. consensus text files (especially in unix world) should end in newline, , there have been problems historically if wasn't present. why should text files end newline? the tool used count lines in file "wc" counts newlines in file, without trailing newline show 3 instead of 4. it improves readability of templates used in generator. consider: https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/controller/templates/controller.rb to remove trailing newline, template have last line of: end<% end -%> instead of: end <% end -%> that seems less readable me. the discussion below refers
Read more

keyboard - Smiles and long press feature in Android -

i've created android keyboard. how add features inserting smilies, , using long keypresses display symbols? to create long-press behavior allows select several options pop-up menu, follow guide (specifically pop-up menu section): http://developer.android.com/guide/topics/ui/menus.html smileys (also known emoticons) combination of keys, understood programs , parsed same way. have do, when clicks smiley face on keyboard, simulate pressing of key combination matching emoticon. example, when clicks smiley, should simulate key presses ':' , ')' :). here's list of emoticons: http://en.wikipedia.org/wiki/list_of_emoticons
Read more

node.js - Bad Request - node js ajax post -

i'm using express 3.0 , node v0.11.0. have button submits form , i'm using ajax post data json object node server. client code is: $('#contact').submit(function(e) { console.log('submit called'); var formdata = json.stringify($('form').serializeobject()); console.log(formdata); $.ajax({ url: "http://localhost:3000/savedata/", type: "post", datatype: 'json', data: {objectdata: formdata}, contenttype: "application/json", complete: function() { console.log('process complete'); }, success: function(data) { console.log('process sucess'); }, error: function() { console.log('process error'); }, }); return false; }); then on server: var express = require('express'); var app = express(); app.set('views', __dirname + '/views'); app.set('view engine', 'jade'); app.use(express.bodyparser());
Read more