How to access objects/arrays defined in JavaScript from Java applets.

Using LiveConnect getMember(String) method of a window JSObject, a Java object of type "Object" is returned but I don't find the expected members defined on it. Neither can I cast it to a JSObject to continue using the getMember().

Accessing DOM nodes and elements (DOM Objects) works as expected.

From stackoverflow

• @Michael Borgwardt

  This is what I'm trying to do.

  Global JavaScript Object.

  foo = {"one":1, "two":2};
  

  Processing code.

  import netscape.javascript.*;
  JSObject win;
  JSObject got1;
  Object   got2;
  
  void setup(){
    size(400,200,P2D);
    background(255);
    win  = JSObject.getWindow(this); //gets the root JSObject
    //got1 = win.getMember("obj"); //fails to cast from Object to JSObject
    got2 = win.getMember("obj"); //works in the sense that I get an Object.
  }
  
  void draw(){
    if (mousePressed == true){
      println(got2.getMember("one")); //fails, there is no getMember() method.
    }
  }
  

  This is perhaps not Processing specific. That's why I didn't originally post the code.

• I'm confused by the line got2 = win.getMember("obj");. It seems like you're expecting that line to get the foo object. As I understand it, win.getMember("obj") will get you the obj property on the DOM window node, which doesn't exist. For example, from this page:

  JSObject win = JSObject.getWindow(this);
  JSObject doc = (JSObject) win.getMember("document");
  JSObject loc = (JSObject) doc.getMember("location");
  

  If you want to get the foo object, the best way I'm aware of is to make a JavaScript method you can call from the Java applet.

  JavaScript:

  <script type="text/javascript">
  var foo = {"one":1, "two":2};
  
  function getFoo() { return foo; }
  </script>
  

  Applet:

  import netscape.javascript.*;
  JSObject win;
  JSObject foo;
  
  void setup(){
    size(400,200,P2D);
    background(255);
    win  = JSObject.getWindow(this); //gets the root JSObject
    foo = (JSObject)win.call("getFoo", null);
  }
  
  void draw(){
    if (mousePressed == true){
      println(foo.getMember("one"));
    }
  }
  

  Matthew Maravillas : Yes, but I don't get why you expect it to get the "foo" object. "JavaScript object" just means it's a object from JavaScript that's been translated to a Java object, specifically JSObject.

  Matthew Maravillas : It did. What's your exception?

  Matthew Maravillas : Random guess: try clearing your classloader cache? Bring up your Java console (Tools - Java console in FF, or right click on the Java icon in your systray and pick the console), and hit x to clear it, then reload.

  Matthew Maravillas : I'm not sure I have any more suggestions for you, except to be pedantic - are you using the exact code I wrote above? I can get the exception if I have getFoo return null, but my line number is 32 instead of 34, so I suspect you have something else there as well.