Mar 16 2011

Specify a Particular Version of Java for Self-Hosted Applets

Yesterday, I looked at how you can run an older version of Java in parallel with an existing installation and then explicitly use the older version for all Java applications. Whilst this is an easy solution to implement it does create potential security risks for computers that are using older versions of Java containing known exploits.

However, you can tighten things up significantly by nominating a specific version of Java to execute your self-hosted Java applets. Of course, the computers of interest will need that version of Java already installed (as per the article for yesterday). Implementing this specification is incredibly easy and can be done by using a small snippet of code, specifically:

classid=”clsid:CAFEEFAC-XXXX-YYYY-ZZZZ-ABCDEFFEDCBA”

  • XXXX is the major version number (so 0015 would be Java 5 or 1.5 in the older numbering and 0016 would be Java 6 or 1.6 in the old numbering),
  • YYYY is the minor version number (this will normally be left as 0000 from Java 5 onwards but would be 0002 in the case of Java 1.4.2),
  • ZZZZ is the update version number (so 0023 would correlate with Update 23).

With that in mind, you can do the following to implement the code:

  1. Open the HTML source file,
  2. Locate the applet tag in the source code referencing your Java applet,
  3. Paste in classid=”clsid:CAFEEFAC-0016-0000-0023-ABCDEFFEDCBA inside the applet tag,
  4. Save and upload your modified source file.

Next time you visit the page on the Internet it will use the specified version of Java (even though the icon in your system tray may indicate you are using the most recent version). If you find that it doesn’t work straight away you might need to clear your browser cache and try again.

Boydo

My name is Boyd and I’m a Service Management Specialist with a knack for operational data gathering, transformation, analysis and reporting.

In 2012, I obtained my Masters of Science in Information Technology through the University of New South Wales @ The Australia Defence Force Academy (UNSW@ADFA).

I was also part of an online community known as the Panasonic Insider Crew in the capacity of “Insider Guru” for Panasonic Australia where I interacted with other tech enthusiasts and find out more about Panasonic's latest gadgets.

I love technology, gadgets, and the Internet and maintain a keen interest in these areas locally, nationally, and globally. I hope by sharing my views on these topics that people will receive an honest point of view from someone with a genuine interest in these topics.

I have also written and edited articles for Neowin - you can check out my articles over @ https://www.neowin.net/news/poster/boyd_chan

I hope you enjoy reading my blog!

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