java-gem

Dead project

This project is dead. I enjoyed pursuing the idea, but it turns out to be a dead-end.

Old README content for historical interest

A command line tool for creating a Ruby Gem from a Java package including all of its dependencies.

Required command line arguments:

• -g, --group Maven group identifier of Java library
• -n, --name Name of Java library
• -v, --version Version of Java library
• -u, --uber-gem Create a single gem containing all of the Java dependencies. (Building skinny gems has issues.)

Optional command line arguments:

• -h, --help Show help
• -o, --output Directory to write the Ruby Gem into (defaults to current working directory)
• -r, --repository Extra Maven repository URL to read from

Example run:

$ lein run --uber-gem --group org.apache.poi --name poi-ooxml --version 3.8

The output is two files:

• org.apache.poi,poi-ooxml-3.8-java.gem

• poi-ooxml.gemspec

    Gem::Specification.new do |s|
      s.date = "2013-03-04"
      s.require_paths = ["lib"]
      s.name = "org.apache.poi,poi-ooxml"
      s.version = "3.8"
      s.homepage = "https://github.com/bruceadams/java-gem"
      s.files = ["lib/stax-api-1.0.1.jar",
                 "lib/poi-ooxml-schemas-3.8.jar",
                 "lib/xmlbeans-2.3.0.jar",
                 "lib/xml-apis-1.0.b2.jar",
                 "lib/dom4j-1.6.1.jar",
                 "lib/poi-3.8.jar",
                 "lib/commons-codec-1.5.jar",
                 "lib/poi-ooxml-3.8.jar",
                 "lib/poi-ooxml.rb"]
      s.authors = ["unknown"]
      s.summary = "RubyGem wrapper for Java package poi-ooxml"
      s.description = "Autogenerated RubyGem wrapper for org.apache.poi/poi-ooxml-3.8"
      s.platform = "java"
    end
  

and a lib directory containing the Java jar files and a generated Ruby file that does a require of each jar file, lib/poi-ooxml.rb

require 'xml-apis-1.0.b2.jar'
require 'dom4j-1.6.1.jar'
require 'stax-api-1.0.1.jar'
require 'xmlbeans-2.3.0.jar'
require 'poi-ooxml-schemas-3.8.jar'
require 'commons-codec-1.5.jar'
require 'poi-3.8.jar'
require 'poi-ooxml-3.8.jar'

Alternate run mechanism:

• Compile a standalone Java jar:

    $ lein uberjar
  

• Run the executable jar:

    $ java -jar target/java-gem-1.0.0-SNAPSHOT-standalone.jar --uber-gem --group org.apache.poi --name poi-ooxml --version 3.8
  

Now

Right now, this tool is a working proof of concept. The code needs to be cleaned up for legibility, with tests and error handling.

As a public demonstration, I have run this tool for several thousand artifacts in Maven Central and have the gems publically available here: http://javagems.org

http://javagems.org is just a static web site, with all the gems themselves in this directory http://javagems.org/gems/ and the rubygems specs, Marshal and related files as generated by:

gem generate_index

The list of Maven artifacts for which I generated gems for comes from a quick (read: sloppy) attempt to grab the latest release version of every jar package in Maven Central.

Future

Instead of generating a uber-gem, as it does now, generate a gem for each individual Java library with gem dependencies that match the Java dependencies.

Enhance this tool so it can run as a Ruby Gems server which will create gems on request. It could act as a Ruby Gem front-end server for a Maven server.

License

Copyright © 2012, 2013 Bruce Adams. Distributed under the Eclipse Public License, see LICENSE for details.