JavaGeek.org - web tag

Add author icons to your weblog comments

Thu, 06 Jul 2006 14:58:47 GMT

Good news, everyone! No, Futurama isn't on the air, yet. But soon. Anyway, I'm still here, albeit a little busy. However, in one of those few late night things I do, I was able to finish up a little project. If you didn't know, there's a site that stores your icons and lets weblogs put icons on the comments, based on the author's email. Gravatar.com provides your site with icons for all the people who comment on your weblog. This works by locally (on your site) generating an MD5 hash of the comment author's email, and then creating an img tag with a source URL that points to gravatar.com and uses the hash to identify the author, and if the author has previously registered that email with gravatar, it will give back an 80x80 picture that was previously loaded by the author. The MD5 hash avoids the need for someone's email address to leave your site, which I think it's good.

I found this concept very interesting, and when I looked at the implementation page, I found out there's very few java support, other than some code on how to create the MD5 and I realized this was a good opportunity to create a taglib. So here it is. jAvatar is a tag library that lets you include a gravatar icon for each of the comments on your weblog. To use it, you just need to add the javatar.jar to your webapp, and the taglib to your comment page. Here's an example on how you can do it on your comments JSP page:

<%@ page language="java" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<%@taglib uri="http://javageek.org/files/taglib/javatar" prefix="javatar"%>
<%
String email = "some_email@somesite.com";
%>

<html>
<head><title>My JSP 'index.jsp' starting page</title></head>

<body>
This is a gravatar:
<javatar:image mail="<%= email %>" imgSize="100" styleClass="gravatar" rating="R" defaultImgUrl="http://mysite.com/img/defIcon.gif" borderColor="F0F"/>
</body>
</html>

Of course, the email should be the comment author's email, and the tag should be put in whatever loop you have for showing your comments. I hope you like it.

Google Web Toolkit (beta) released

Wed, 17 May 2006 01:04:20 GMT

Google has just released the beta version of the Google Web Toolkit (GWT). The GWT is a Java-based toolkit that lets you create AJAX-enabled pages using Java. The main idea of the toolkit is that once you create your app following the GWT API, you will then compile your Java classes into Javascript and HTML, so you can deploy your application in any web server (it doesn't require Java to run your application, since everything is converted).

GWT provides a new, fresh and different concept to the Java web toolkits realm by providing a Java to Javascript compiler, however you might be able to see some similarities with other Java frameworks, and even with some non-java frameworks, like Ruby On Rails. For example, in order to create a new project, GWT provides you with some scripts that you use to create the basic directory structure and templates. The Widgets (UI components) look somewhat like Swing or Wicket components, and the hosted mode looks like how RoR does its development. Still, the whole Java-to-Javascript concept seems new to me, and it looks like you can do some really good-looking ajaxy-feeling sites with it. GWT provides back-end interaction via RPC mechanisms too, because not everything can be done on the client-side.

I will definitely keep an eye on this framework, since I think that it will provide much needed RAD features for Java web development.

Comparing Web Frameworks: RIFE

Fri, 17 Mar 2006 15:19:10 GMT

Well, it seems that the series of articles comparing all the different frameworks using Simon's initial set of requirements is expanding. This time, Geert Bevin, the creator of RIFE, has done the same thing, using his own framework.

I've always found RIFE very interesting, but a little daunting for new users. It uses a lot of cool concepts, like web continuations, blueprints, constrained meta data, etc., but if you are starting at server-side development using Java, or if you come from a much simpler framework like Struts, then you might find all of this just a little bit too much.

Also, it seems that there are at least 3 ways to accomplish the same task for many tasks that you want to do. This says wonders about the flexibility of the framework, but if you only want to 'get it done', you will probably stall with RIFE, trying to figure out which one of the options is the best for you; and then, after selecting one, you might start thinking that the other ones might have been better.

I'm sure that the amount of work Geert has put into his framework is making RIFE very flexible. However, I would still choose Wicket over RIFE, as Wicket provides a simpler entry point, in my opinion. I guess the real issue is how does each framework handle more complex requirements, though.