Alternate Constructors in Groovy

14 September 2017

There are a variety of ways to construct objects in Groovy. We were looking for something more dynamic where we could parameterize the object to be constructed.

We found a couple different things that worked to instantiate an object:

import groovy.transform.*

class MyClass {
    String first
    String last

def map = [first: 'f', last: 'l']

// instantiate from literal class reference
println new MyClass(map)
println MyClass.newInstance(map)
println (map as MyClass)
println map.asType(MyClass)

// instantiate from a variable reference the class
def clazz = MyClass

println map.asType(clazz)
// println (map as clazz) // 'as' operator doesn't like 'clazz' variable
println clazz.newInstance(map)

Filed Under: Code Groovy