GPath

class Person {
 String address
 Name name
}

class Name {
 String first
 String last
}

List ps = []
// create mockup data
10.times { i ->
 Name nm = new Name(first:"first ${i + 1}", last:"last $i")
 ps << new Person(name:nm, address:"${(i+1)*7} Street")
}
assert ps.class.name == "java.util.ArrayList"


//print out each array element
for (p in ps) { System.out.print(p.address + ", ") }; System.out.println("") // Java, yuck!
ps.each { p -> print "${p.address}, " }; println "" // Groovy
println ps.collect { p -> p.address } // returns list, more Groovy


// Now for some GPath magic!!
println ps.address // returns list, same as .collect above
assert  ps.name.class.name == "java.util.ArrayList" // list of Names
assert  ps.name[0].class.name == "Name"
println ps.name.first // returns list
println ps.name.last // returns list

http://groovyconsole.appspot.com/script/449005