Where JSTL comes to short (Part 1 : I speak to you in klingon)

JSTL (JavaServer Pages Standard Tag Library / JSR-52) has been around for quite some time now. It was certainly a breath of fresh air when it was introduced as an alternative to inline java in JSP files. Unfortunately I still find it lacking. I will try to describe these problems as best I can in a number of posts here on my blog. Please comment if you think I have misunderstood some of the concepts along the way.

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Write gif-files with “standard java” in java 5

Java 5 supports reading GIF files. Java 6 also supports writing GIF files. I needed a nice way to write gif images from Java 5. A lot of GIF packages exists for Java 5. But most of them does not give the same nice result as the implementation by Sun. Since I couldn’t upgrade to Java 6 in my project, I backported parts of the javax.imageio package from openjdk-6-src-b09-11_apr_2008 (Can be downloaded from http://openjdk.java.net), so that it can run on Java 5. I’ve introduced new package names, so that this package will not mess with the standard javax.imageio package. Feel free to use it. But remember that it comes with no guarantees! If you find any problems you can mail me at java6-gif-backport/at/jakobielsen_dot_net.

Read more at http://www.jakobnielsen.net/java6-gif-backport

Logging with log4j in jetty-maven-plugin

The jetty-maven-plugin is a great way to run a webapp during development. But the main problem is that it doesn’t print debug messages when you are using commons-logging. The reason is that it by default uses org.apache.commons.logging.impl.SimpleLog. This logger can’t print debug messages. Here is the solution on how to change this default behaviour so that it use Log4J instead.

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Automagic taglib descriptors with XDoclet and Maven 2

From time to time I do write JSP taglibs. The java-part of this is almost fun. But writing the tld-files by hand is something that simply is just boring. Therefor I use XDoclet (webdoclet) to generate these tld-files for me. This small tutorial will show you what XDoclet tags you must set in your taglib class, and finally how to get XDoclet doing the magic with Maven 2.

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