In groovy, is there a way to check if an object has a given method?

Question

Assuming that I have an object someObj of indeterminate type, I'd like to do something like:

def value = someObj.someMethod()

Where there's no guarantee that 'someObj' implements the someMethod() method, and if it doesn't, just return null.

Is there anything like that in Groovy, or do I need to wrap that in an if-statement with an instanceof check?

question from:https://stackoverflow.com/questions/1534167/in-groovy-is-there-a-way-to-check-if-an-object-has-a-given-method

Answer 1

Use respondsTo

class Foo {
   String prop
   def bar() { "bar" }
   def bar(String name) { "bar $name" }
}

def f = new Foo()

// Does f have a no-arg bar method
if (f.metaClass.respondsTo(f, "bar")) {
   // do stuff
}
// Does f have a bar method that takes a String param
if (f.metaClass.respondsTo(f, "bar", String)) {
   // do stuff
}