build: build cross platform gems

Rakefile

@@ -82,8 +82,9 @@ Rake::TestTask.new do |t|
   t.verbose = true
 end
 
-spec = Gem::Specification.load(File.expand_path('../jaro_winkler.gemspec', __FILE__))
-Gem::PackageTask.new(spec).define
+%w[jaro_winkler jaro_winkler.java]
+  .map { |name| Gem::Specification.load(File.expand_path("../#{name}.gemspec", __FILE__)) }
+  .each { |spec| Gem::PackageTask.new(spec).define }
 
 task 'CHANGELOG.md' do
   sh 'conventional-changelog -p angular -i CHANGELOG.md -s'

ext/jaro_winkler/extconf.rb

@@ -1,16 +1,5 @@
 # frozen_string_literal: true
 
-if RUBY_ENGINE == 'ruby'
-  require 'mkmf'
-  $CFLAGS << ' -std=c99 '
-  create_makefile('jaro_winkler/jaro_winkler_ext')
-else
-  open('Makefile', 'wb') do |file|
-    file.write <<-MAKEFILE
-.PHONY: install
-install:
-\techo "Cannot compile C Extension, fall back to pure Ruby version."
-clean:
-    MAKEFILE
-  end
-end
+require 'mkmf'
+$CFLAGS << ' -std=c99 '
+create_makefile('jaro_winkler/jaro_winkler_ext')

jaro_winkler.gemspec

@@ -8,7 +8,7 @@ Gem::Specification.new do |spec|
   spec.version = JaroWinkler::VERSION
   spec.authors = ['Jian Weihang']
   spec.email = 'tonytonyjan@gmail.com'
-  spec.extensions = ['ext/jaro_winkler/extconf.rb'] if RUBY_ENGINE == 'ruby'
+  spec.extensions = ['ext/jaro_winkler/extconf.rb']
   spec.summary = 'An implementation of Jaro-Winkler distance algorithm written \
   in C extension which supports any kind of string encoding.'
   spec.description = 'jaro_winkler is an implementation of Jaro-Winkler \

jaro_winkler.java.gemspec

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+require 'jaro_winkler/version'
+
+Gem::Specification.new do |spec|
+  spec.name = 'jaro_winkler'
+  spec.version = JaroWinkler::VERSION
+  spec.authors = ['Jian Weihang']
+  spec.email = 'tonytonyjan@gmail.com'
+  spec.summary = 'An implementation of Jaro-Winkler distance algorithm written \
+  in C extension which supports any kind of string encoding.'
+  spec.description = 'jaro_winkler is an implementation of Jaro-Winkler \
+  distance algorithm which is written in C extension and will fallback to pure \
+  Ruby version in platforms other than MRI/KRI like JRuby or Rubinius. Both of \
+  C and Ruby implementation support any kind of string encoding, such as \
+  UTF-8, EUC-JP, Big5, etc.'
+  spec.homepage = 'https://github.com/tonytonyjan/jaro_winkler'
+  spec.license = 'MIT'
+  spec.files = Dir['lib/**/*.rb']
+  spec.add_development_dependency 'bundler', '~> 1.7'
+  spec.add_development_dependency 'rake', '~> 12.0'
+  spec.add_development_dependency 'rake-compiler'
+  spec.add_development_dependency 'minitest'
+  spec.platform = 'java'
+end