这个NB~~~！
Constructors in Groovy can be invoked in a classic Java way, but we can
also use lists or maps to create objects. Groovy supports an explicit
coersion of a list to a constructor with the
as keyword.
Or we can rely on the implicit coersion when Groovy looks at the type
of the variable to automatically convert the list to the right
constructor call.
// Default constructor invocation:
def url1 = new URL('http', 'www.mrhaki.com', 80, '/')
assert 'http' == url1.protocol
assert 'www.mrhaki.com' == url1.host
assert 80 == url1.port
assert '/' == url1.file
assert '/' == url1.path
// Explicit coersion with as keyword:
def url2 = ['http', 'www.mrhaki.com', 80, '/'] as URL
assert 'http' == url1.protocol
assert 'www.mrhaki.com' == url2.host
assert 80 == url2.port
assert '/' == url2.file
assert '/' == url2.path
// Implicit coersion by type of variable:
URL url3 = ['http', 'www.mrhaki.com', 80, '/']
assert 'http' == url3.protocol
assert 'www.mrhaki.com' == url3.host
assert 80 == url3.port
assert '/' == url3.file
assert '/' == url3.path
http://mrhaki.blogspot.com/2009/09/groovy-goodness-using-lists-and-maps-as.html