How can I add methods from a Java class as global functions in Javascript using Rhino?
I'm not real familiar with Rhino, but something like this should work:
for(var fn in utils) {
if(typeof utils[fn] === 'function') {
this[fn] = (function() {
var method = utils[fn];
return function() {
return method.apply(utils,arguments);
};
})();
}
}
Just loop over the properties of utils
,and for each one that is a function, create a global function that calls it.
EDIT: I got this working in a Groovy script, but I had to set utils in the bindings, not on the engine like in your code:
import javax.script.*
class Utils {
void foo(String bar) {
println bar
}
}
ScriptEngine engine = new ScriptEngineManager().getEngineByName("js");
engine.eval("""
for(var fn in utils) {
if(typeof utils[fn] === 'function') {
this[fn] = (function() {
var method = utils[fn];
return function() {
return method.apply(utils,arguments);
};
})();
}
}
foo('foo'); // prints foo, sure enough
""",new SimpleBindings("utils":new Utils()))
I'm not sure how this would work using the JSR-223 API, but with the Rhino API, you can create a FunctionObject
with the method you want to add like this.
Class[] parameters = new Class[] { String.class, Integer.class };
Method dealMethod = Utils.class.getMethod("deal", parameters);
engine.put("deal", new FunctionObject("deal", dealMethod, scope));
The documentation is available at https://www.mozilla.org/rhino/apidocs/org/mozilla/javascript/FunctionObject.html.
You might need to reference the Rhino library to access the FunctionObject
class, and I'm not sure how you would get the scope
object with the JSR-223 API (although, it's possible that null
would work).