diff --git a/activesupport/lib/active_support/xml_mini/jdom.rb b/activesupport/lib/active_support/xml_mini/jdom.rb
new file mode 100644
index 0000000000..d795d55690
--- /dev/null
+++ b/activesupport/lib/active_support/xml_mini/jdom.rb
@@ -0,0 +1,162 @@
+raise "JRuby is required to use the JDOM backend for XmlMini" unless RUBY_PLATFORM =~ /java/
+
+require 'jruby'
+include Java
+
+import javax.xml.parsers.DocumentBuilder unless defined? DocumentBuilder
+import javax.xml.parsers.DocumentBuilderFactory unless defined? DocumentBuilderFactory
+import java.io.StringReader unless defined? StringReader
+import org.xml.sax.InputSource unless defined? InputSource
+import org.xml.sax.Attributes unless defined? Attributes
+import org.w3c.dom.Node unless defined? Node
+
+# = XmlMini JRuby JDOM implementation
+module ActiveSupport
+ module XmlMini_JDOM #:nodoc:
+ extend self
+
+ CONTENT_KEY = '__content__'.freeze
+
+ NODE_TYPE_NAMES = %w{ATTRIBUTE_NODE CDATA_SECTION_NODE COMMENT_NODE DOCUMENT_FRAGMENT_NODE
+ DOCUMENT_NODE DOCUMENT_TYPE_NODE ELEMENT_NODE ENTITY_NODE ENTITY_REFERENCE_NODE NOTATION_NODE
+ PROCESSING_INSTRUCTION_NODE TEXT_NODE}
+
+ node_type_map = {}
+ NODE_TYPE_NAMES.each { |type| node_type_map[Node.send(type)] = type }
+
+ # Parse an XML Document string into a simple hash using Java's jdom.
+ # string::
+ # XML Document string to parse
+ def parse(string)
+ if string.blank?
+ {}
+ else
+ @dbf = DocumentBuilderFactory.new_instance
+ xml_string_reader = StringReader.new(string)
+ xml_input_source = InputSource.new(xml_string_reader)
+ doc = @dbf.new_document_builder.parse(xml_input_source)
+ merge_element!({}, doc.document_element)
+ end
+ end
+
+ private
+
+ # Convert an XML element and merge into the hash
+ #
+ # hash::
+ # Hash to merge the converted element into.
+ # element::
+ # XML element to merge into hash
+ def merge_element!(hash, element)
+ merge!(hash, element.tag_name, collapse(element))
+ end
+
+ # Actually converts an XML document element into a data structure.
+ #
+ # element::
+ # The document element to be collapsed.
+ def collapse(element)
+ hash = get_attributes(element)
+
+ child_nodes = element.child_nodes
+ if child_nodes.length > 0
+ for i in 0...child_nodes.length
+ child = child_nodes.item(i)
+ merge_element!(hash, child) unless child.node_type == Node.TEXT_NODE
+ end
+ merge_texts!(hash, element) unless empty_content?(element)
+ hash
+ else
+ merge_texts!(hash, element)
+ end
+ end
+
+ # Merge all the texts of an element into the hash
+ #
+ # hash::
+ # Hash to add the converted emement to.
+ # element::
+ # XML element whose texts are to me merged into the hash
+ def merge_texts!(hash, element)
+ text_children = texts(element)
+ if text_children.join.empty?
+ hash
+ else
+ # must use value to prevent double-escaping
+ merge!(hash, CONTENT_KEY, text_children.join)
+ end
+ end
+
+ # Adds a new key/value pair to an existing Hash. If the key to be added
+ # already exists and the existing value associated with key is not
+ # an Array, it will be wrapped in an Array. Then the new value is
+ # appended to that Array.
+ #
+ # hash::
+ # Hash to add key/value pair to.
+ # key::
+ # Key to be added.
+ # value::
+ # Value to be associated with key.
+ def merge!(hash, key, value)
+ if hash.has_key?(key)
+ if hash[key].instance_of?(Array)
+ hash[key] << value
+ else
+ hash[key] = [hash[key], value]
+ end
+ elsif value.instance_of?(Array)
+ hash[key] = [value]
+ else
+ hash[key] = value
+ end
+ hash
+ end
+
+ # Converts the attributes array of an XML element into a hash.
+ # Returns an empty Hash if node has no attributes.
+ #
+ # element::
+ # XML element to extract attributes from.
+ def get_attributes(element)
+ attribute_hash = {}
+ attributes = element.attributes
+ for i in 0...attributes.length
+ attribute_hash[attributes.item(i).name] = attributes.item(i).value
+ end
+ attribute_hash
+ end
+
+ # Determines if a document element has text content
+ #
+ # element::
+ # XML element to be checked.
+ def texts(element)
+ texts = []
+ child_nodes = element.child_nodes
+ for i in 0...child_nodes.length
+ item = child_nodes.item(i)
+ if item.node_type == Node.TEXT_NODE
+ texts << item.get_data
+ end
+ end
+ texts
+ end
+
+ # Determines if a document element has text content
+ #
+ # element::
+ # XML element to be checked.
+ def empty_content?(element)
+ text = ''
+ child_nodes = element.child_nodes
+ for i in 0...child_nodes.length
+ item = child_nodes.item(i)
+ if item.node_type == Node.TEXT_NODE
+ text << item.get_data.strip
+ end
+ end
+ text.strip.length == 0
+ end
+ end
+end
diff --git a/activesupport/test/xml_mini/jdom_engine_test.rb b/activesupport/test/xml_mini/jdom_engine_test.rb
new file mode 100644
index 0000000000..b745228994
--- /dev/null
+++ b/activesupport/test/xml_mini/jdom_engine_test.rb
@@ -0,0 +1,153 @@
+require 'abstract_unit'
+require 'active_support/xml_mini'
+
+if RUBY_PLATFORM =~ /java/
+
+class JDOMEngineTest < Test::Unit::TestCase
+ include ActiveSupport
+
+ def setup
+ @default_backend = XmlMini.backend
+ XmlMini.backend = 'JDOM'
+ end
+
+ def teardown
+ XmlMini.backend = @default_backend
+ end
+
+ # def test_file_from_xml
+ # hash = Hash.from_xml(<<-eoxml)
+ #
+ #
+ #
+ #
+ # eoxml
+ # assert hash.has_key?('blog')
+ # assert hash['blog'].has_key?('logo')
+ #
+ # file = hash['blog']['logo']
+ # assert_equal 'logo.png', file.original_filename
+ # assert_equal 'image/png', file.content_type
+ # end
+
+ def test_exception_thrown_on_expansion_attack
+ assert_raise NativeException do
+ attack_xml = <<-EOT
+
+
+
+
+
+
+
+
+ ]>
+
+ &a;
+
+ EOT
+ Hash.from_xml(attack_xml)
+ end
+ end
+
+ def test_setting_JDOM_as_backend
+ XmlMini.backend = 'JDOM'
+ assert_equal XmlMini_JDOM, XmlMini.backend
+ end
+
+ def test_blank_returns_empty_hash
+ assert_equal({}, XmlMini.parse(nil))
+ assert_equal({}, XmlMini.parse(''))
+ end
+
+ def test_array_type_makes_an_array
+ assert_equal_rexml(<<-eoxml)
+
+
+ a post
+ another post
+
+
+ eoxml
+ end
+
+ def test_one_node_document_as_hash
+ assert_equal_rexml(<<-eoxml)
+
+ eoxml
+ end
+
+ def test_one_node_with_attributes_document_as_hash
+ assert_equal_rexml(<<-eoxml)
+
+ eoxml
+ end
+
+ def test_products_node_with_book_node_as_hash
+ assert_equal_rexml(<<-eoxml)
+
+
+
+ eoxml
+ end
+
+ def test_products_node_with_two_book_nodes_as_hash
+ assert_equal_rexml(<<-eoxml)
+
+
+
+
+ eoxml
+ end
+
+ def test_single_node_with_content_as_hash
+ assert_equal_rexml(<<-eoxml)
+
+ hello world
+
+ eoxml
+ end
+
+ def test_children_with_children
+ assert_equal_rexml(<<-eoxml)
+
+
+
+
+
+ eoxml
+ end
+
+ def test_children_with_text
+ assert_equal_rexml(<<-eoxml)
+
+
+ hello everyone
+
+
+ eoxml
+ end
+
+ def test_children_with_non_adjacent_text
+ assert_equal_rexml(<<-eoxml)
+
+ good
+
+ hello everyone
+
+ morning
+
+ eoxml
+ end
+
+ private
+ def assert_equal_rexml(xml)
+ hash = XmlMini.with_backend('REXML') { XmlMini.parse(xml) }
+ assert_equal(hash, XmlMini.parse(xml))
+ end
+end
+
+else
+ # don't run these test because we aren't running in JRuby
+end