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<p><a href="https://scripting.dev.java.net/">JSR-223</a> is designed to allow Java access to many scripting languages. This means that it also provides hooks for Groovy to those other languages.</p>

<p>JSR-223 comes with Java 6. Here is how you can use it. First we define a script manager:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
mgr = new javax.script.ScriptEngineManager()
</pre></td></tr></table>

<p>Now, we can call out to JavaScript:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
// included in Java 6
println 'javascript: ' + mgr.getEngineByName("javascript").eval('''
function factorial(n) {
    if (n == 0) {
        return 1;
    }
    return n * factorial(n - 1);
}
factorial(4)
''')
</pre></td></tr></table>

<p>Or JRuby:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
// requires jruby and jruby-engine jars
println 'jruby: ' + mgr.getEngineByName("jruby").eval('''
def factorial(n)
    if n == 0
        1
    else
        n * factorial(n - 1)
    end
end
factorial(4)
''')
</pre></td></tr></table>

<p>Or Jython:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
// requires jython and jython-engine jars
engine = mgr.getEngineByName("jython")
engine.eval('''
def factorial(n):
    i=fact=1
    while i &lt;= n:
        fact=fact*i
        i=i+1
    return fact

result = factorial(4)
''')
println 'jython: ' + engine.result
</pre></td></tr></table>

<p>Or Clojure:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
// requires clojure and clojure-engine jars
// Note: doesn't seem officially supported, hacked a version from here:
// http://wiki.github.com/pmf/clojure-jsr223
engine = mgr.getEngineByName("clojure")
println 'clojure: ' + engine.eval('''
(defn factorial [n]
   (if (&lt; n 2)
       1
       (* n (factorial (- n 1)))))
(factorial 4)
''')
</pre></td></tr></table>

<p>Or Jaskell:</p>
<table class="wysiwyg-macro" data-macro-name="code" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e2NvZGV9&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
// requires jaskell and jaskell engine and jparsec and jfunutil jars
engine = mgr.getEngineByName("jaskell")
engine.eval('factorial n = if n > 0 then n * factorial (n-1) else 1')
println 'jaskell: ' + engine.eval('factorial 4')
</pre></td></tr></table>

<p>The output from running these scripts is:</p>
<table class="wysiwyg-macro" data-macro-name="noformat" style="background-image: url(/plugins/servlet/confluence/placeholder/macro-heading?definition=e25vZm9ybWF0fQ&amp;locale=en_GB&amp;version=2); background-repeat: no-repeat;" data-macro-body-type="PLAIN_TEXT"><tr><td class="wysiwyg-macro-body"><pre>
javascript: 24.0
jruby: 24
jython: 24
clojure: 24
jaskell: 24
</pre></td></tr></table>

<p>See also: <a class="confluence-link" href="/display/GROOVY/JSR+223+Scripting+with+Groovy" data-linked-resource-id="80695" data-linked-resource-type="page" data-linked-resource-default-alias="JSR 223 Scripting with Groovy" data-base-url="http://docs.codehaus.org">Accessing Groovy from Java via JSR-223</a></p>