Passing json data from javascript to Java

Question

I'm trying to pass json data from javascript to java, like below. The idea is to pass the data to the java code as a javascript object (and not aa string which I know can be done ). I've tried the code below without success - idea was to use NativeJson.stringify to convert from a javascript object to a Java string, however this results in an Undefined instance instead of the expected string. Any idea on this could be achieved much appreciated.

in javascript file "test.js"

parser.fct ( {"abc":123,"def":456} )

in java

//1.binds javascript calls to Java
...
ScriptEngine engine = new ScriptEngine...
Bindings bindings = engine.createBindings();
bindings.put("parser", new Parser());
engine.eval("test.js");

//2. in Parser class
public void fct(Object obj){
   Context ctx = Context.enter();
   ScriptableObject scope = ctx.initStandardObjects();
   Object json = NativeJSON.stringify(ctx, scope, obj, null,null);

   //json returned is of type Undefined

}

Answer 1

Could not find a way to use NativeJSON.stringify(). I ended up building the json string "by hand", ie Iterating on the property ids of the native javascript object and adding these properties to a java Map.

The Map is then transformed into a json object using new JSONObject(map);

link to source code https://gist.github.com/eleco/c2bc77dca9ecc844a924