groovy: Have a field name, need to set value and don't want to use switch

Question

I have an object with several fields,

class TestObj { 
  def field1
  def field2
}

I have a pair of values v1="field1" and v2="value2" I would like to set v2 into the appropriate field based on the name of v1, but I'd prefer not to have to do it with a switch or if statements, I keep thinking there has to be a much "groovier" way of achieving the result other than doing something like this:

setValues(def fieldName, def fieldVal) {
  if (fieldName.equals("field1")) {
    field1 = fieldVal
  }
  if (fieldName.equals("field2")) {
    field2 = fieldVal
  }
}

I've tried doing this:

setValues(def fieldName, def fieldVal) {
  this['${fieldName}'] = fieldVal
}

However that fails, saying there's no property ${fieldName}

Thanks.

Answer 1

You can use GStrings when you get a field, like this:

def obj = new TestObj()
def fieldToUpdate = 'field1'
obj."$fieldToUpdate" = 3

Answer 2

In Groovy you don't have to define a property to have a property. Use getProperty and setProperty called property access hooks in Groovy:

class TestObj {
    def properties = [:]
    def getProperty(String name) { properties[name] }
    void setProperty(String name, value) { properties[name] = value }

    void setValues(def fieldName, def fieldVal) {setProperty(fieldName, fieldVal)}
}

def test = new TestObj()
test.anyField = "anyValue"
println test.anyField

test.setValues("field1", "someValue")
println test.field1

test.setValues("field2", "anotherValue")
println test.field2