Matt RaibleMatt Raible is a Java Champion and Developer Advocate at Okta.

The JHipster Mini-Book The JHipster Mini-Book is a guide to getting started with hip technologies today: Angular, Bootstrap, and Spring Boot. All of these frameworks are wrapped up in an easy-to-use project called JHipster.

This book shows you how to build an app with JHipster, and guides you through the plethora of tools, techniques and options you can use. Furthermore, it explains the UI and API building blocks so you understand the underpinnings of your great application.

For book updates, follow @jhipster-book on Twitter.


Over 10 years ago, I wrote my first blog post. Since then, I've authored books, had kids, traveled the world, found Trish and blogged about it all.

JavaScript and CSS Concatenation with wro4j

This past weekend, I decided it was about time to fix my YSlow score on this site. I did the easiest thing first by moving all my JavaScript files to the bottom of each page. Then I turned on GZip compression using Roller's built-in CompressionFilter. These changes helped, but the most glaring problem continued to be too many requests. To solve this, I turned to wro4j (as recommended on Twitter) to concatenate my JS and CSS files into one.

I have to say, I'm very happy with the results. I'm now sitting at a YSlow (V2) score of 75; 90 if I use the "Small Site or Blog" ruleset. I believe I can improve this by adding expires headers to my images, js and css. More than anything, I'm impressed with wro4j, its great support and easy setup. I was looking for a runtime solution (b/c I didn't want to have to rebuild Roller) and it seems to be perfect for the job. Furthermore, wro4j minifies everything on the fly and they'll have an expires header filter in the next release.

JAWR and the YUI Compressor are other alternatives to this filter, but I'm currently sold on wro4j. First of all, it passed the 10-minute test. Secondly, it didn't require me to modify Roller's build system.

At this point, if I'm going to implement JS/CSS concatenation and minification in AppFuse and Roller, wro4j seems like the best option. If you disagree, I'd love to hear your reasoning.

TIP: See Javascript Compression in Nexus for information on using YUI Compressor with Maven.

Posted in Roller at Nov 09 2009, 10:44:44 AM MST 16 Comments