How to verify if an object has certain property?

Question

I want to use either a value of expected property or a specified default. How to achieve this in groovy?

Let\'s look at the example:

def printName(ob         


        

Answer 1

Assuming your object is a Groovy class, you can use hasProperty in the object metaClass like so:

def printName( o ) {
  if( o.metaClass.hasProperty( o, 'name' ) && o.name ) {
    println "Printing Name : $o.name"
  }
  else {
    println o
  }
}

So, then given two classes:

class Named {
  String name
  int age

  String toString() { "toString Named:$name/$age" }
}

class Unnamed {
  int age

  String toString() { "toString Unnamed:$age" }
}

You can create instance of them, and test:

def a = new Named( name: 'tim', age: 21 )
def b = new Unnamed( age: 32 )

printName( a )
printName( b )

Which should output:

Printing Name : tim
toString Unnamed:32