How to check whether java plugin is enabled or not using javascript?

Question

I have an .aspx page which consists of applet code. In order to run this, the browser must have an active Java plugin.

Is there any way to check whether a Java plugin is installed and enabled, using Javascript?

Answer 1

window.navigator.javaEnabled()//true if java enabled 

window.navigator.plugins // will give u all the plugins installed in the browser

Answer 2

I would suggest you to go for the method recommended by Oracle

<script src="http://www.java.com/js/deployJava.js"></script>
<script>
    if (deployJava.versionCheck('1.6+')) {            
        var url = "http://docs.oracle.com/javase/tutorialJWS/deployment/webstart/examples/Notepad.jnlp";

        <!-- you can also invoke deployJava.runApplet here -->
        deployJava.createWebStartLaunchButton(url, '1.6.0'); 
    } else {
        document.location.href="http://oracle.com";
    }
</script> 

This is taken from http://docs.oracle.com/javase/tutorial/deployment/deploymentInDepth/jreVersionCheck.html

You should also take a look at Java Deployment Toolkit http://docs.oracle.com/javase/6/docs/technotes/guides/jweb/deployment_advice.html#deplToolkit