XML transformation with Groovy, JDOM2 and XPath

jdom2_transform.groovy

/*
 * Copyright 2013 (c) Andrey Hihlovskiy
 * License: MIT (http://opensource.org/licenses/MIT)
 */

@Grab('org.jdom:jdom2:2.0.6')
@Grab('jaxen:jaxen:1.1.6')
@GrabExclude('jdom:jdom')

import org.jdom2.*
import org.jdom2.input.*
import org.jdom2.xpath.*
import org.jdom2.output.*

def xml = '''<?xml version="1.0" encoding="UTF-8"?>
<page>
  <!-- test comment -->
    <content>
        <section>
            <link>
                <url>/some/old/url</url>
            </link>
            <link>
                <url>/some/old/url</url>
            </link>
        </section>
        <section>
            <link>
                <url>
                    /a/different/old/url?with=specialChars&amp;escaped=true
                </url>
            </link>
        </section>
    </content>
</page>'''

Document doc = new SAXBuilder().build(new StringReader(xml))

def urls = XPathFactory.instance().compile('//url').evaluate(doc)

for(def url in urls) {
  url.text = url.text.replaceAll($//some/old/url/$, '/a/new/and/improved/url')
  url.text = url.text.replaceAll($//a/different/old/url/$, '/a/different/new/and/improved/url')
}

new XMLOutputter().with {
  format = Format.getRawFormat()
  format.setLineSeparator(LineSeparator.NONE)
  // XmlOutputter can write to OutputStream or Writer, which is sufficient for most cases
  output(doc, System.out)
}