A Groovy script has no class declaration or
main() method, but if we compile the script class to Java bytecode, it has. This means we can write a Groovy script, compile the source and use the resulting class in Java.
// File: Sample.groovy package com.mrhaki.blog println 'Hello from Groovy'
Next we can compile this script and use Java to invoke the class. We must make sure we add the Groovy library to the classpath, but that is all.
$ groovyc Sample.groovy $ java -cp .:$GROOVY_HOME/embeddable/groovy-all-1.6.5.jar com.mrhaki.blog.Sample Hello from Groovy