如何从groovy导入一个闭包到java？

Question

I'm trying to extract a closure from a groovy script. I define the closure as

def printMe = {str ->println str}

in my groovy file, and then try to use it by grabbing it from the binding as follows:

GroovyScriptEngine gse = new GroovyScriptEngine(new String[] { "scripts" });
Binding binding = new Binding();
gse.run("test.groovy", binding);
Closure cls = (Closure) binding.getVariable("printMe");
cls.call("foo");

But I get the following error when I run this.

groovy.lang.MissingPropertyException: No such property: 
    printMe for class: groovy.lang.Binding
    at groovy.lang.Binding.getVariable(Binding.java:55)
    at GroovyTry.main(GroovyTry.java:19)

Is there a way to grab a closure (or a plain method) from a groovy script?

Answer 1

What happens if you omit the def from your closure declaration?

printMe = { str -> println str }

By using def, I think the printMe variable becomes local to the script, rather than going in the Binding

Read more about Scoping and the Semantics of "def"