解决方法
class Order { int id String toString() { "O$id" } } def list = [ new Order( id: 1 ),new Order( id: 2 ),new Order( id: 3 ) ] // Sort ascending (modifies original list as well) println list.sort { it.id } // Sort descending (modifies original list as well) println list.sort { -it.id } // Sort ascending (don't modify original) println list.sort( false ) { it.id } // Sort descending (don't modify original) println list.sort( false ) { -it.id }