Groovy is a dynamic language for the Java Virtual Machine that adds features from languages like Python, Ruby, and Smalltalk. It supports domain-specific languages and integrates with all Java objects. Groovy compiles to Java bytecode so it runs on the JVM and can be used anywhere Java is used, including J2EE, Swing, Spring, and Seam applications. Groovy allows writing JUnit tests and development in Eclipse with debugging support.

4. dynamic types (sort of) Value Java Type def a = “hello” String def a = 1 Integer def a = 1.5 BigDecimal def a = [1,2,3,4] ArrayList def person = [name: “Ashish”, age: 27] LinkedHashMap

10. Closures: Why useful? def newCourses = courses.findAll { course -> course.courseType == 3 }

11. Closures: Why useful? def newCourses = courses.findAll { it.courseType == 3 }

15. Gant: Groovy ANT includeTargets << gant.targets.Clean cleanPattern << [ '**/*~' , '**/*.bak' ] cleanDirectory << 'build' target ( stuff : 'A target to do some stuff.' ) { println ( 'Stuff' ) depends ( clean ) echo ( message : 'A default message from Ant.' ) otherStuff ( ) } target ( otherStuff : 'A target to do some other stuff' ) { println ( 'OtherStuff' ) echo ( message : 'Another message from Ant.' ) clean ( ) } setDefaultTarget ( stuff )

16. GANT: Listing Tasks gant -p clean Action the cleaning. clobber Action the clobbering. Do the cleaning first. otherStuff A target to do some other stuff stuff A target to do some stuff. Default target is stuff.

18. Spring Web Flows class BookController { ... def shoppingCartFlow = { showCart { on( &quot;checkout&quot; ).to &quot;enterPersonalDetails&quot; on( &quot;continueShopping&quot; ).to &quot;displayCatalogue&quot; } ... displayCatalogue { redirect(controller: &quot;catalogue&quot; , action: &quot;show&quot; ) } displayInvoice() } }