JSF HTML Whitespace, JS, and CSS Compression

This is the second approach to whitespace removal, JS, and CSS compression. In my article Whitespace Servlet Filter, I mentioned that I tried a number of approaches using htmlcompressor to accomplish this task.

This was my second approach which was to wrap the ResponseWriter in JSF to accomplish this task. The approach worked, but was abandoned before I finished writing some additional code to handle AJAX. This could be easily resolved with code that is similar to that found in Whitespace Servlet Filter.

This approach is very specific to JSF and relies on the project being pure JSF. The filter approach is more flexible in my judgement. I did think it was important to publish the code though on Github.

The code for the project can be found here: jsf-html-compressor.

Whitespace Servlet Filter

A few years ago I worked on a number of different techniques to strip the whitespace out of web pages. My goal was to come up with a solution for JSF pages. I tried a number of different solutions,  but they were all based on a framework called htmlcompressor which is a now abandoned project in the archives of Google Code. This framework used the Google Closure Compiler to handle the heavy lifting.

This solution worked flawlessly when we tested it on JSF pages, but there was a push to use pre-minified pages for static content, and leave JSF pages alone. I abandoned this project until I was using Google PageSpeed to check the speed of some pages to enhance their performance.  I remembered this approach I tried back in 2011, and tried it again with great success and only minor tweaking. I have decided to publish the code on Github.

The project can be found here: whitespace-filter.

A Simple Method to invoke @PreDestroy on a Class

I was experimenting with how to invoke a @PreDestroy annotated method in a class. This will approach will work with other annotations as well.

How do I check if a Class is an instanceof another Class without initializing it?

Illustration: Cathy Wilcox

We had a recent security audit and a question was posed about how to check a Class without doing an instanceof. This turned out to be a great learning experience. There were a couple of issues that needed to be resolved, first we were loading a Class by passing in its name using something similar to the line below: This will load the Class, but from here how do we check that it is an instanceof without instantiating it?
This can be solved by using isAssignableFrom(Class clazz) as shown below. In this case we are checking if SolientGreen is Green. Some of you will find the moral paradox of being "Green" with Soilent Green.
The second issue is a more potential security problem. How do we load the Class without initializing it. If the Class has a static initializer, the code is executed when the class is loaded. Alas, this is handled by using a variation of Class.forName(String name, boolean initialize, ClassLoader loader) which takes a boolean to determine if the class should be initialized, and a ClassLoader if you want to specify a specific loader.

Finally, we can check the Class like this: When this is run, you will not see the message. Very nice indeed!

So here is the remaining code for education and entertainment:
The code for the project can be downloaded from Bitbucket here: assignable