how to add static methods using groovy mixin

Question

hi, I want to use the mixin feature of groovy to import methods as "class(static) methods" instead of instance methods. When i use mixin even though i have a static method in my mixin class it gets converted into a instance method in the destination class.I want the imported method to be a class(static) method.Is there a good way to do it?

Answer 1

I don't know of any way to add static methods to a class using mixins, but you can add static methods to a class via the metaClass.static property. Here's an example that adds a static fqn() method that prints the fully-qualified name of a class

Class.metaClass.static.fqn = { delegate.name }
assert String.fqn() == "java.lang.String"

If you want to add fqn() (and other static methods) to several classes (e.g. List, File, Scanner), you could do something like

def staticMethods = [fqn: {delegate.name}, fqnUpper: {delegate.name.toUpperCase()}]    

[List, File, Scanner].each { clazz ->

    staticMethods.each{methodName, methodImpl ->
        clazz.metaClass.static[methodName] = methodImpl
    }
}