Calling Java function from JavaScript

Question

I am trying to call a Java Function as a callback from JavaScript using JavaFX. First, I added the Java class as a member of window during initialization:

JSObject jsobj = (JSObject) currentWebEngine.executeScript("window");
jsobj.setMember("java", this);

The Java request function is described as follows inside the Platform.runLater():

String script = "document.makeRequest('"+inputString+"')";
currentWebEngine.executeScript(script);

After the asynchronous request is done in the javascript side, it should call a java function to return the result. However, I am getting exceptions in that side. I even tried calling a function without argument and still doesn't work:

window.java.returnResult();

But I get the following exception:

Exception in runnable netscape.javascript.JSException: TypeError: 'undefined' is not an object

It has nothing to do with the asynchronous request since I even tried calling it directly in makeRequest() function and got the same error. Any idea what I did wrong in that area? The previous code is integrated in a Desktop JFrame application, not an applet.

• jewelsea: Does the example demonstrating WebView to Java callbacks in the Oracle WebView tutorial work for you?

Answer 1

I managed to find the solution of the problem. The following code was called a bit early and therefore the class is not registered within javascript:

JSObject jsobj = (JSObject) currentWebEngine.executeScript("window");
jsobj.setMember("java", this);

I just called it at the listener of the web engine and it worked.

Answer 2

Use DWR, You can use java methods through JavaScript.

• Sami: As far as I can see, DWR requires a Java Server to communicate with a Web browser. That is not what I am aiming to do. I have a Swing desktop Application that embeds JavaScript using JavaFX