Yes, Velocity has been around for quite awhile now, and it was intended to address many of the problems inherent in (older versions of) JSP.
Nowdays JSP (especially JSP2) coding techniques and technologies have rather caught up with velocity. Your assesment that it doesnt add much value over the EL capabilities in JSP2 is pretty much on the mark. Of course it wasnt always this way and for a long time velocity was much nicer. (Still looks nicer ;->) I reckon you are also correct in believing that velocity design provided a lot of the inspiration for the jstl stuff. -----Original Message----- From: Larry Meadors [mailto:[EMAIL PROTECTED] Sent: Friday, 27 February 2004 21:26 To: [EMAIL PROTECTED] Subject: Re: [OT] JSP or Velocity >>> [EMAIL PROTECTED] 02/27/04 5:44 AM >>> > I am starting to develop an application using struts and have been > looking round the rest of the Jakarta project and came across the > Velocity project. > > I was interested to see which which people recommended for a relative > newbie After looking at velocity, I am certainly of the opinion that it adds no value over jsp2/jstl. It offers absolutely nothing that the jsp2/jstl combination does not. The only difference is that velocity is a bit more terse (if/else/end instead of <c:choose>/<c:when>/<c:otherwise>) and that it uses # instead of the <>. It is important to note that I am talking about jsp2 and tomcat 5, not the jsp1 in tomcat 4. A while back I looked in detail at the jsp/velocity comparison on the velocity site. There are several issues with the comparison. The person writing the case study was cleary biased towards velocity and had never even considered JSTL (which in all fairness may not have been available at that time). Looking at the code (both the velocity and jstl versions are below) I think that velocity clearly had an influence on the jsp2/jstl constructs. The first thing I noticed was that the two pages do not do the same thing. The jsp turns off the session (the vm does not). The jsp stores variables that are never used which were factored out in the vm version. The vm version is missing required code (for example, the repCode and urlEvent variables are never defined). The jsp page is also *very* poorly written using scriptlets. You should rarely need to use scriptlets in jsp1/jstl pages, and I suspect with jsp2/jstl, you will not ever *need* to. With struts, you do not need to use <jsp:useBean> tags either because the controller does that for you. The jsp2/jstl version is a bit more verbose because it is based on xml so you cannot have things like if/else/end because they are unbalanced, but other than that, there are no significant differences. After converting the page to use JSTL and eliminating ALL of the <% %> stuff, we get something more like this: === The JSP version: === <table width="600" border="0" cellspacing="0" cellpadding="4" bgcolor="white"> <tr> <td> <i><b>Topic: ${meeting.topic}</b></i> <c:forEach list="${meeting.storedEventsIterator}" var="event"> <c:set var="yapper" value="${meeting.participation[event.fromId]}" /> <c:choose> <c:when test="${event.class.name eq 'fqcn.URLPushedEvent'}"> <c:choose> <c:when test="${yapper.role eq 'R'}"> <c:set var="repId" value="${yapper.participantId}" /> <font color="#000000"><b>${yapper.name}:</b></font> </c:when> <c:otherwise> <font color="#0000f0"><b>${yapper.name}:</b></font> </c:otherwise> </c:choose> <a href="${event.storedData}">"${event.storedData}"</a> <br> </c:when> <c:when test="${event.class.name eq 'fqcn.ChatEvent'}"> <c:choose> <c:when test="${yapper.role eq 'R'}"> <font color="#000000"><b>${yapper.name}:</b></font> <c:set var="repId" value="${yapper.participantId}" /> </c:when> <c:otherwise> <font color="#0000f0"><b>${yapper.name}:</b></font> </c:otherwise> </c:choose> <a href="${event.storedData}">"${event.storedData}"</a> <br> </c:when> </c:choose> </c:forEach> <hr> <br>${meeting.meetingId}:${repId}<br> </td> </tr> </table> === The velocity version: === <table width="600" border="0" cellspacing="0" cellpadding="4" bgcolor="white"> <tr> <td> <i><b>Topic: $meeting.getTopic()</b></i><p> #foreach( $event in $meeting.getStoredEventsIterator() ) #set( $yapper = $meeting.getParticipation($event.getFromId()) ) #if( $event.getClass().getName().equals($urlEvent) ) #if( $repRole.equals($yapper.getRole()) ) #set( $repId = $yapper.getParticipantId() ) <font color="$blk"><b>$yapper.getName()</b></font> #else <font color="$blu"><b>$yapper.getName()</b></font> #end <a href="$event.getStoredData()">$event.getStoredData()</a> <br> #elseif( $event.getClass().getName().equals($chatEvent) ) #if($repRole.equals($yapper.getRole()) ) #set( $repId = $yapper.getParticipantId() ) <font color="$blk"><b>$yapper.getName()</b></font> #else <font color="$blu"><b>$yapper.getName()</b></font> #end $event.getStoredData() <br> #end #end <hr> <br>$meeting.getMeetingId():$repId<br> </td> </tr> </table> === Larry --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
