Parse in Java accessible in Java

Question

I have

public JSONObject parseXML(String xml) {
    JSONObject jsonObject = XML.toJSONObject(xml);
    return jsonObject;
}

from the org.json library.

In Nashorn I want to be able to do

let foo = parseXML(someXMLString);
console.log(foo.someProperty);

What I end up getting is a NPE. But if I do

let foo = parseXML(someXMLString);
console.log(JSON.parse(foo.someProperty));

it works. is there an equivalent function to JSON.parse I can do in Java land and return without needing that JSON.parse in JavaScript?

edit: Please note it is NOT a duplicate. I am not asking how to parse for certain values in the JSON, I am asking how to return the entire object, so that it is parseable by Nashorn without the extra JSON.parse

Answer 1

You can call JSON.parse or any other script function from Java. Example code to call JSON.parse from Java:

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import jdk.nashorn.api.scripting.JSObject;

public class Main {
    public static void main(String[] args) throws Exception {
        ScriptEngineManager m = new ScriptEngineManager();
        ScriptEngine e = m.getEngineByName("nashorn");

        // get ECMAScript JSON.parse
        JSObject jsonParse = (JSObject)e.eval("JSON.parse");

        // initialize/retrieve JSON string here
        String str = "{ \"foo\": 42, \"bar\": { \"x\": \"hello\" } }";

        // call JSON.parse from Java
        Object parsed = jsonParse.call(null, str);

        // expose parsed object to script
        e.put("obj", parsed);

        // access parsed object from script
        e.eval("print(obj.foo)");
        e.eval("print(obj.bar.x)");
    }
}