Javascript, Calling Java Applet method throws TypeError

Question

I have a simple Applet class:

package com.myapp;

class MyApplet extends Applet {
    public String myMethod() {
       return "Hello";
    }
}

I have compiled my with other my java classes into jarfile. Then I have run this jar files main class to ensure that jar is correctly created. It works.

Then I try to embed this Applet into my page:

<script type="application/javascript">
    $(document).ready(function () {
        console.log(document.MyApplet.myMethod())
    });
</script>

<applet archive="myjar.jar" code="com.myapp.MyApplet.class" id="MyApplet" name="MyApplet" width=100 height=100></applet>

This throws me this error:

Uncaught TypeError: Cannot read property 'myMethod' of undefined

Which means that document.MyApplet returns undefined

When I try to call it like this:

document.getElementById('MyApplet').myMethod();

It throws me this:

Uncaught TypeError: document.getElementById(...).myMethod is not a function

Did I miss something?

I have tested this on:

Chrome 57.0.2987.133 (64-bit)
Firefox 52.0.2 (32-bit)

Applet was compiled by using JDK 8.

Did you try this http://stackoverflow.com/questions/11536455/calling-java-method-in-javascript — Mohamed Abbas, Apr 15 '17 at 12:04
@MohamedAbbas this answer is about making ajax requests and it is not connected to my quesion. — Mr.D, Apr 15 '17 at 12:18

Suraj Rao · Answer 1 · 2017-04-15T12:49:08.417

0

Try

    console.log(document.getElementById('MyApplet').myMethod())

You can grab elements by getElementById

According to the docs you need to include the following script to run the applet.

<script src=
  "https://www.java.com/js/deployJava.js"></script>
<script>
    <!-- applet id can be used to get a reference to
    the applet object -->
    var attributes = { id:'MyApplet',
        code:'jcom.myapp.MyApplet.class',  width:1, height:1} ;
    var parameters = { jnlp_href: 'MyApplet.jnlp'} ;
    deployJava.runApplet(attributes, parameters, '1.6');
</script>

edited Apr 15 '17 at 12:49

answered Apr 15 '17 at 12:03

Suraj Rao

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I have received `Uncaught TypeError: document.getElementById(...).myMethod is not a function` error. Do I need to turn something on in my browser? – Mr.D Apr 15 '17 at 12:07
hmm .. just found http://stackoverflow.com/questions/7278626/javascript-to-java-applet-communication – Suraj Rao Apr 15 '17 at 12:10
are you sure of the path? try `archive="./myjar.jar"` – Suraj Rao Apr 15 '17 at 12:23
Still throws same error. My applet in browser has zero width and height even if I set them 100, is it connected with my error? – Mr.D Apr 15 '17 at 12:26
width and height even if 0 will still be in the DOM.. can you try `console.log(document.getElementById('MyApplet'))` – Suraj Rao Apr 15 '17 at 12:28
It returns me `` – Mr.D Apr 15 '17 at 12:29

score 0 · Accepted Answer · answered May 25 '17 at 09:31

The main problem behind this task was that Last versions of Firefox, Chorme and Safari does not support applets and they wont launch them

The only browser that is still can launch applets is Internet Explorer and it also requires explicit permissions which are considered very dangerous.

Javascript, Calling Java Applet method throws TypeError

2 Answers2