iText with Ruby on Rails using Ruby Java Bridge

(see discussion)
Step 1 : install JDK 1.5+ and above
Step 2: check JAVA_HOME is set
Step 3: install the rjb gem

gem install rjb -v 1.1.2

see discussion

Step 4: Place iText files in a known directory
Step 5 (optional): check to see from your application if you can access iText (discussion)

ruby script/console # in the working directory of your application
jar = "c:/ruby/iText-2.1.2u.jar"
require 'rjb'
doc = Rjb::import("com.lowagie.text.Document")

Step 6: From your controller call the various iText classes

 1 class LettersController < ApplicationController

 2   require 'rjb'
 3   
 4   Rjb::load("c:/ruby/iText-2.1.2u.jar;c:/ruby/pdf.jar")
 5   

 6   def download
 7     pdfwriterclass = Rjb::import("com.lowagie.text.pdf.PdfWriter")
 8     documentclass = Rjb::import("com.lowagie.text.Docuemnt") 

 9     bytearrayclass = Rjb::import("java.io.ByteArrayOutputStream")
10     paragraphclass = Rjb::import("com.lowagie.text.Paragraph")
11     byteArrayInstance = byteArrayClass.new()

12     document = documentClass.new()
13     writer = pdfWriterClass.getInstance(document,byteArrayInstance)
14     document.open()
15     document.add(paragraphClass.new("Hello!!!"))
16     document.close()

17     fileinbytes = byteArrayInstance.toByteArray()
18     send_data(fileInBytes, {:filename => "Letters For Printing.pdf", :type => "application/pdf"})

19   end
20 
21 end
22 

(recommended) Please place the

require 'rjb'

in your application.rb

WARNING: Do not call Rjb::load() more than once throughout your application. Put Rjb::load in your application.rb file and then load all your jars there like so Rjb::load(abc.jar;def.jar;ghi.jar).