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POJRuby, Warbler, and Java's CLASSPATH
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  1. POJRuby, Warbler, and Java's CLASSPATH
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    copied!<p>I've been developing applications in JRuby lately and really enjoying it, but I've been running into a wall when it comes to packaging my project into a JAR file when it includes external Java libraries. If the project does not depend on any external Java library JAR files, I run into no problems.</p> <p>Below is an example application. This code works perfectly fine when running the <code>./bin/my_proj</code> executable. But, when I package it into a JAR file, the external Java library cannot be loaded because it is not found on the CLASSPATH. </p> <p>When I unpackage my application's JAR file, I can see that it includes all of my code as well as the <code>vendor</code> directory containing the external Java library. So, everything's where it should be.</p> <p><strong>lib/my_proj/application.rb</strong></p> <pre><code>java_import 'com.somecompany.somejavalibrary.SomeJavaLibraryClass' module MyProj class Application &lt; SomeJavaLibraryClass # Some code implementing SomeJavaLibraryClass end end </code></pre> <p><strong>lib/my_proj.rb</strong></p> <pre><code>require 'pathname' module MyProj def root Pathname.new(__FILE__).join('..', '..').expand_path end def start setup_environment Application.new end def setup_environment @setup ||= false unless @setup @setup = true require 'java' $CLASSPATH &lt;&lt; root.join('vendor').to_s # Setup Java CLASSPATH $LOAD_PATH &lt;&lt; root.join('lib').to_s # Setup Ruby LOAD_PATH require 'some_java_library' # Load the external Java library from it's JAR require 'my_proj/application' end end extend self end </code></pre> <p><strong>bin/my_proj</strong></p> <pre><code>#!/usr/bin/env ruby $:.unshift File.expand_path( File.join('..', '..', 'lib'), __FILE__ ) require 'my_proj' MyProj.start </code></pre> <p><strong>config/warble.rb</strong></p> <pre><code>Warbler::Config.new do |config| config.features = %w(gemjar compiled) config.autodeploy_dir = 'pkg' config.dirs = %w(assets bin config lib) config.java_libs += FileList['vendor/*.jar'] end </code></pre> <p><strong>vendor/some_java_library.jar</strong></p> <pre><code># This is the external Java library </code></pre>
 

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