How to check/verify Java Version on client machine

There are many different versions of Java, and to be sure, that your end users will have no problems with the Java Uploader, it is necessary to verify the Java version actually installed (and whether it is installed at all). This article describes how you can do it using JavaScript.

Solution

Oracle created a Deployment Toolkit Script to make it possible to check what Java versions are installed on the machine. This is a simple .js file which you link to your HTML page and after that you can receive information about Java version through the special JavaScript functions.

You can find Deployment Toolkit Script and its detailed description on this page:

http://docs.oracle.com/j..._advice.html#deplToolkit

Let’s see how we implement Java verification on your site.

There are three options available:

1. No Java installed. In this case, we should send the user to the Test Java page (http://www.java.com/en/download/testjava.jsp) where the user will see all necessary instructions how to install it.

2. Outdated version of Java installed. In this case, we should send the user to the Verify Java Version page (http://java.com/en/download/installed.jsp). On this page the user can update the Java to the latest version.

3. The latest version of Java installed. In this case, we can be sure that our Java applet will work as expected and display it on the page.

We will use two methods of the Deployment Toolkit Script:

• deployJava.versionCheck() - to check if the specified Java version is installed.

• deployJava.getJREs() – to check if any Java is installed (in this case, the method will return an empty array).

This code example illustrates how to display the Java uploader or an appropriate link to www.java.com depending on the Java plug-in status:

<script type="text/javascript" src="http://java.com/js/deployJava.js"></script>
<script type="text/javascript" src="Scripts/aurigma.uploader.js"></script> 
<script type="text/javascript"> 
    var javaVersion = "1.7.0_25"; 
if(deployJava.versionCheck(javaVersion) || deployJava.getBrowser() == "MSIE") { 
var u = $au.uploader({
    id: 'Uploader1'    
    // configure ActiveX/Java Uploader        
});

u.writeHtml(); 
} else { 

if (deployJava.getJREs().length == 0){
document.write("There are no JREs detected on your machine. Go to <a href='http://www.java.com/en/download/testjava.jsp'>test java</a> page. Install Java and come back.");
} else {
document.write("You have too old Java version. Please go to <a href='http://java.com/en/download/installed.jsp'>verify java</a> page, update your Java and come back.");
}   
} 
</script>

Note: Don’t forget to download the http://java.com/js/deployJava.js and link it to the HTML page!

Edited by moderator Monday, August 29, 2016 6:37:33 AM(UTC)  | Reason: Not specified