Un caractère est une unité minimale abstraite de texte qui n'a pas forcément toujours la même représentation graphique.

La plate-forme Java utilise Unicode pour son support des caractères mais il est fréquent de devoir traiter des données textuelles encodées différemment en entrée ou en sortie d'une application. Java propose plusieurs classes et méthodes pour permettre la conversion de nombreux encodages de caractères de et vers Unicode.

Les applications Java qui doivent traiter des données non encodées en Unicode, sont lues avec l'encodage adéquat, stockées et traitées en Unicode et exportent le résultat de Unicode vers l'encodage initial ou l'encodage cible.

La version 5.0 de Java propose un support de la version 4.0 d'Unicode.

La JSR 204 « Unicode Supplementary Character Support » définit le support des caractères étendus d'Unicode dans la plate-forme Java. Ceci permet le support des caractères au-delà des 65546 possibles sur un stockage dans 2 octets.

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<jsp-config>
<jsp-property-group>
<url-pattern>*.jsp</url-pattern>
<page-encoding>UTF-8</page-encoding>
</jsp-property-group>
</jsp-config>

About a month ago, I blogged about my love/hate relationship with Eclipse. I was asked by a few people to share my tips on how I was able to speed it up so here we go… As a side note, this article is not about comparing IDEs, please refrain from displaying your hate for the IDE or your preference for another… This post is just about optimizations that help Eclipse run faster for those who use it. I’ve described each tip for Windows, Linux and MacOS users. Once you have gone through all the optimization tips, Eclipse should start within 10 seconds and run much smoother than before.

[edit]: most of those tips will speed up your Eclipse experience, not just the startup time. Classes will open faster, jumping from one definition to another will be faster. Viewing method javadocs will be faster… Unfortunately, none of that can be timed precisely so there is no specific benchmark about the actual speed gains for each tip.

When compared to NetBeans, I find that Eclipse is a lot slower, particularly when doing enterprise development. To try and speed Eclipse up, I’ve taken the JVM settings that NetBeans uses and applied them to Eclipse. The result is a vast improvement in performance. The default JVM settings in Eclipse aren’t optimal.

JVM GC tuning is a vast field that books have been written about. Mostly, we’re happy to accept whatever defaults the JVM figures out, at most cranking up heap and permGen size when we’re out of memory (again).

Besides the fact that a glorified Texteditor with a compiler attached needs gigabytes of memory, the darned thing was still slow, often becoming unresponsive for some seconds. This sucks.

Joda-Time provides a quality replacement for the Java date and time classes.

Joda-Time is the de facto standard date and time library for Java prior to Java SE 8. Users are now asked to migrate to java.time (JSR-310).

Joda-Time is licensed under the business-friendly Apache 2.0 licence.

Open source libraries are very popular in Java world. Nowadays Java/J2EE/Android developers often work with Java-based projects which using a lot of open source Java libraries.

One issue with using open source Java libraries is how to find documentation/source code for these open source libraries fast and easily? It is tedious and time consuming to search for the source code, download and attach source code packages to the libraries. If your project has 40 libraries, how long will it take to find source code for all libraries?

The solution is to use this Eclipse plugin to do the task for you with only one mouse click. This Eclipse plugin will help to find source code for open source Java libraries automatically from Internet. Just right click on a Java library, choose the menu item "Attach Java Source" and wait. The source code for the library will be found and attached to the Java library in several seconds.

The Chinese guy who knows everything about Java!

Un livre qui a l'air excitant !

Une façon intéressante de découvrir Groovy, très orientée Test Driven Development