Alternatively you could use a for loop as shown in the Groovy Docs:
def map = ['a':1, 'b':2, 'c':3]
for ( e in map ) {
print "key = ${e.key}, value = ${e.value}"
}
/*
Result:
key = a, value = 1
key = b, value = 2
key = c, value = 3
*/
One benefit of using a for loop as opposed to an each closure is easier debugging, as you cannot hit a break point inside an each closure (when using Netbeans).