Editing Apache Groovy (section)

===JSON and XML processing===
On JavaScript Object Notation ([[JSON]]) and XML processing, Groovy employs the [[Builder pattern]], making the production of the data structure less verbose. For example, the following XML:

<syntaxhighlight lang="xml">
<languages>
  <language year="1995">
    <name>Java</name>
    <paradigm>object oriented</paradigm>
    <typing>static</typing>
  </language>
  <language year="1995">
    <name>Ruby</name>
    <paradigm>functional, object oriented</paradigm>
    <typing>duck typing, dynamic</typing>
  </language>
  <language year="2003">
    <name>Groovy</name>
    <paradigm>functional, object oriented</paradigm>
    <typing>duck typing, dynamic, static</typing>
  </language>
</languages>
</syntaxhighlight>

can be generated via the following Groovy code:

<syntaxhighlight lang="groovy">
def writer = new StringWriter()
def builder = new groovy.xml.MarkupBuilder(writer)
builder.languages {
  language(year: 1995) {
    name "Java"
    paradigm "object oriented"
    typing "static"
  }
  language (year: 1995) {
    name "Ruby"
    paradigm "functional, object oriented"
    typing "duck typing, dynamic"
  }
  language (year: 2003) {
    name "Groovy"
    paradigm "functional, object oriented"
    typing "duck typing, dynamic, static"
  }
}
</syntaxhighlight>

and also can be processed in a streaming way through <code>StreamingMarkupBuilder</code>. To change the implementation to JSON, the <code>MarkupBuilder</code> can be swapped to <code>JsonBuilder</code>.<ref>{{cite web |url=http://groovy.codehaus.org/gapi/groovy/json/JsonBuilder.html |title=JsonBuilder |access-date=2012-10-07 |archive-url=https://web.archive.org/web/20121002221510/http://groovy.codehaus.org/gapi/groovy/json/JsonBuilder.html |archive-date=2012-10-02 |url-status=dead }}</ref>

To parse it and search for a functional language, Groovy's <code>findAll</code> method can serve:

<syntaxhighlight lang="groovy">
def languages = new XmlSlurper().parseText writer.toString()

// Here is employed Groovy's regex syntax for a matcher (=~) that will be coerced to a 
// boolean value: either true, if the value contains our string, or false otherwise.
def functional = languages.language.findAll { it.paradigm =~ "functional" }
assert functional.collect { it.name } == ["Groovy", "Ruby"]
</syntaxhighlight>