Databinding

first_try.groovy

class Test {
  String a
  String b
  String c
}

class Test2 {
  String a
  String b
  String c
  String d
}

def tmp = new Test(a: "asdf", b: "ddd", c: "eeee")
def tmp2 = new Test2(tmp.properties - [class: Test])


println tmp2.properties

mergeable_trait.groovy

import groovy.transform.ToString

trait Mergeable {
    def leftShift(Object value) {
        println "$this << $value"
        this.properties.each {
            if (value.properties.containsKey(it.key) && it.key != "class") {
                this."${it.key}" = value."${it.key}"
            }
        }
        return this
    }
}

@ToString
class Test {
  String a
  String b
  String c
}

@ToString
class Test2 implements Mergeable {
  String b
  String c
  String d
}

def tmp = new Test(a: "asdf", b: "ddd", c: "eeee")
def tmp2 = new Test2() << tmp

println tmp2