This weeks giveaway

[Carl Trusiak]

This week we are giving away four copies of the book "JSTL in Action".
And the best part... The Author, Shawn Bayern, will be online to answer your questions
Let's all give him a warm JavaRanch Welcome!
Thanks to the people at Manning Publishing for the book's
[ August 20, 2002: Message edited by: Carl Trusiak ]

[Rashid Ali]

I warmly welcome the author, Mr Shawn Bayernto for being with us.
The comment by Sheriff - Mapraputa Is, proves its usefulness which was attached with intimation message by javaranch which attracts me to this books:

The words "in action" in the book's title aren't just words, it is a methodological principle. The discussion concentrates on practice rather than theory... )

Could you please briefly introduce your book for us enabling us to have a review of what you've offered after your untold efforts to write it for us.
Taking this opportunity, i would like to ask you that why did you choose to write a book on JSTL that means what's the reason that you could have interest in writing on this topic.
Thanks again for passing you precious time with folks of Javaranch here.
Kind Regards
Rashid
[ August 20, 2002: Message edited by: Rashid Ali ]

[Shawn Bayern]

Originally posted by Rashid Ali:
Could you please briefly introduce your book for us enabling us to have a review of what you've offered after your untold efforts to write it for us.

Hi Rashid. Sure thing. The book is designed to give everyone -- whether a page author or a Java programmer -- all of the background and details they need to begin using JSTL productively. JSTL is the JSP Standard Tag Library; it offers a new set of standard tags for use in JSP pages. Since its tags come from the same standards group that produced JSP, it's worth learning the tags in order to simplify your JSP pages and make them more maintainable. (Using JSTL, you can in most cases avoid scriptlets entirely. It works with either a model 1 or model 2 approach.) "JSTL in Action" was written to help you do this.

Taking this opportunity, i would like to ask you that why did you choose to write a book on JSTL that means what's the reason that you could have interest in writing on this topic.

Well, I was the reference-implementation lead for JSTL under the Java Community Process (and for the Apache Software Foundation), so it was natural for me to want to help explain the technology by writing a book about it.
As for why I got involved initially, I was drawn to JSTL because of its promise (and the way I saw it fulfilling that promise) of making JSP both (a) more accessible to a wider group of users and (b) easier, across the board, to use and maintain. Even as an advanced developer, I prefer to use JSTL -- and that says a lot, since the expert group ensured that the tags would be usable even by nonprogrammers.
JSTL also provides a standard API for configuring the JSTL tags, handling things like default DataSources and locales in JSP pages, and other important back-end features. Thus, even if you're an advanced programmer who focuses on Java-based components instead of HTML-filled JSP pages, "JSTL in Action" will help you support the page authors you do work with.

Thanks again for passing you precious time with folks of Javaranch here.

No problem! I've been around in this JSP forum for a while, attempting to answer questions -- especially JSTL-related ones. Please let me know if you've got any questions about the book, JSTL, or JSP in general. (I've also been active in the JSP 2.0 expert group and am happy to discuss any public information related to JSP 2.0, of which the JSTL expression language is a major part.)
Best wishes,

[chris coleman]

First of all, welcome. Now here is my question for the author. Any idea when the major commercial app servers will be supporting JSTL and JSP 2.0. Thank you!

[Shawn Bayern]

Originally posted by chris coleman:
Any idea when the major commercial app servers will be supporting JSTL and JSP 2.0. Thank you!

Well, Sun and Apache both offer implementations of JSTL that will work in any JSP 1.2 app server. I'm unfortunately not privy to other companies' internal schedules, but I know that Resin is working on a JSTL implementation, and other companies have privately told me they're planning to do so as well. (There are pointers to the Sun and Apache implementations at http://java.sun.com/products/jstl.)
As for JSP 2.0, it's a bit early to speculate, since the JSP 2.0 standard isn't finalized yet. We recently entered Public Final Draft (PFD), and JSP 2.0 should go FCS sometime this year, though that's never definite. There is a working prototype of a JSP 2.0 implementation available from http://developer.java.sun.com/developer/earlyAccess/jsp/index.html; it includes some features that I and other have added to the Tomcat 4.0 code base. Specifically, it supports the EL in body test and some debugging features related to JSR-45.
By the way, to help you get started using JSTL quickly, Manning Publications and I have made a bundle available from http://www.manning.com/getpage.html?project=bayern&filename=source.html. This bundle contains a JSP container, a JSTL implementation, and all of the examples from
JSTL in Action.
Hope that helps; feel free to let me know if you've got any more questions!
[ August 20, 2002: Message edited by: Shawn Bayern ]

[Doug Wang]

Welcome to this ranch!
Here is my question. Who should learn JSTL, web authors, Java programmers or both?
[ August 20, 2002: Message edited by: Doug Wang ]

[Tiago Nodari]

I know only a little of JSTL, and as Shawn mentioned in another post, one of the main reasons behind the EL is so web authors can have something a little easier to work with, and as for the Java Programmers the benefits is writing less code in JSP... I haven't yet learned the benefits of the EL, and I think a lot of Java Programmers will feel the same way I did. Disliking the EL, but I think we have to give it fair chance, after all they put in a lot of hard work and there is somethin useful for all of us
Shawn mentioned that his book is in the style of Web Development with JSP, which I really liked, learn by great examples
Plus I want to thank everyone at Javaranch, not only is this a great forum, but the initiave of book giveaways is great...
[ August 21, 2002: Message edited by: Tiago Nodari ]

[Shawn Bayern]

Originally posted by Doug Wang:
Welcome to this ranch!
Here is my question. Who should learn JSTL, web authors, Java programmers or both?

Good question, Doug!
JSTL was designed to be accessible to web-page authors, but Java programmers should learn it too for two reasons:
- Most Java programmers have to design web pages at some point in their lives, and using JSTL instead of scriptlets will help ensure that their pages can be maintained by others who might not have the same programming background. JSTL's tags also provide abstraction and reusability. The old adage that "the best code I write is the code I don't have to write at all" definitely applies; instead of writing your own components, you can use the ones that JSTL provides. These tags wrap common features in convenient ways; we thought through lots of details and edge conditions when we designed the spec. I'm a pretty advanced Java developer myself, but I find that when I need to develop web pages, things go faster if I use JSTL, and the pages are ultimately friendlier to nonprogrammers or less-advanced programmers.
- JSTL provides a Java API (for programmers) that lets you configure the behavior of JSTL tags, expose data in JSTL-accessible formats, and handle other important back-end tasks. Even if you just develop back-end components and someone else develops the presentation tier, you might want to use the JSTL API to ensure that the presentation tier behaves appropriately and has access to correct defaults (e.g., a default DataSource, or a default locale) and data.
There's a more subtle reason that programmers might want to learn JSTL: knowing what page authors know, programmers will be able to structure data more conveniently for the presentation tier. In other words, it's easier to give data to a web-page author when you know the JSTL expression language; you want to know what the page author will be able to access easily.
Please let me know if you've got any followup questions. (Needless to say, JSTL in Action covers both the JSTL tags and the JSTL API, so it's useful for page authors and programmers who want to learn JSTL.)
[ August 21, 2002: Message edited by: Shawn Bayern ]

[Sandep Chaturvedi]

In some projects in my company we are planning to make extensive use of JSTL. I have been successful to run most of these in Weblogic. I am sure your book will be a great help for our developers.
I had some concerns regarding some of the features in JSTL which can create confusion in developers. On one side, there is a big push to use MVC framework where JSP is for presentation with data access logic moving to EJB layer or DAOs. On the other hand there are SQL Execution tags as part of JSTL!!
Are we trying to provide adhoc data access capabilities to page designers? That can create a indirection as to who is responsible for what. Why create a functionality which can lead to anti pattern??
"Those quick prototypes and simple applications can turn in a maze of problems"
This is same problem when we started with JSP. JSP centric application became challenge for team to maintain and this can lead to same problems all over again. Even though anything is possible in JSP, things like SQL Tags should be a big no-no as standards.
JSTL should a compliment to other J2EE components and not a competition to them (like JDO/EJB/DAO)
Just my 2 cents.

[Shawn Bayern]

Originally posted by Sandep Chaturvedi:
JSTL should a compliment to other J2EE components and not a competition to them (like JDO/EJB/DAO)

I agree with you entirely. See this thread for a discussion of why we included SQL tags in JSTL.
In addition to what's said there, it's also interesting to point out that JSTL provides a standard TagLibraryValidator class that lets you restrict what tag libraries your page-authors uses. That is, you can cause the container to throw a translation-time error if a developer uses the SQL tags; this is useful if you want to rule them out entirely in your application. Certainly, the SQL tags have less relevance in large organizations that follow patterns (versus smaller ones that need to hammer out solutions quickly).

[Sandep Chaturvedi]

Thanks for the quick response. It was just of point of view and wanted to share. It definitely takes other products such as XSQL out of market and I am glad for that (too many technologies in a mix)
I had another doubt, since I have not gone through the source code for JSTL, I was not sure if thread safety was taken into account and tested in a complex scenarios. This being so new, I am sure there is no large scale deployment at present -- though there may be some in progress and this kind of information will be useful for them.
If you can throw some light on that and enlighten us

[Shawn Bayern]

Originally posted by Sandep Chaturvedi:
I had another doubt, since I have not gone through the source code for JSTL, I was not sure if thread safety was taken into account and tested in a complex scenarios. This being so new, I am sure there is no large scale deployment at present -- though there may be some in progress and this kind of information will be useful for them.

As the reference-implementation lead for JSTL, I ensured the Sun/Apache implementation handles things like tag-handler lifecycle correctly and very carefully. The general topic of thread safety isn't an issue for JSTL itself; the Servlet API describes the relationship between the servlet container and the threads it creates. But I've long been a cheerleader for correct maintaince of tag-handler lifecycles, and the Sun/Apache JSTL implementation should handle it perfectly.
Did you mean something else by "thread safety"?
The implementation has been thoroughly tested, and we know of no issues; I just want to make sure I understand your question completely.

[Sandep Chaturvedi]

Thanks for the reply.
I just wanted to be sure that if we want to deploy it in large scale application, we are not guinea pig for testing it and wait for next release.
It was not correct for me to even question that.

[Doug Wang]

Hi Shawn,
Thanks for your informative reply!
"Knowing what page authors know" can be one of the reasons that Java programmer should learn JSTL.

Originally posted by Shawn Bayern:
Please let me know if you've got any followup questions. (Needless to say, JSTL in Action covers both the JSTL tags and the JSTL API, so it's useful for page authors and programmers who want to learn JSTL.)

No followup questions, for you've answered what I want to ask(about your book's covering JSTL API).
And let's begin our happy learning trip from JSTL in Action.

[Reda Mokrane]

Welcome to the ranch, Shawn Bayern. Thanks for being here.
Is there a sample chapter that are available for download? It's just to get a better idea of what JSTL is about.
Thanks

[Shawn Bayern]

Originally posted by Reda Mokrane:
Welcome to the ranch, Shawn Bayern. Thanks for being here.
Is there a sample chapter that are available for download? It's just to get a better idea of what JSTL is about.
Thanks

Sure, we've made several sample chapters available. You can download a few from http://www.manning.com/bayern, and even more from http://www.TheCoderCoop.com. (The sample chapters are free on both sites; the latter one requires a free registration, though, while the former does not.)
You can also read things like "About the book" and one of the appendixes (a quick-reference guide to JSTL) at http://www.manning.com/bayern.
Hope that helps,

[anshul agrawal]

I would like to know from where can i download JSTL implementation for my Tomcat 4.0 because on sun site it comes integrated with tomcat at first hand not as separate piece. Also want to know where toget standard doc for it

[Shawn Bayern]

Originally posted by anshul agrawal:
I would like to know from where can i download JSTL implementation for my Tomcat 4.0 because on sun site it comes integrated with tomcat at first hand not as separate piece. Also want to know where toget standard doc for it

You can download the open-source Jakarta implementation of JSTL from http://jakarta.apache.org/taglibs; click on "Standard Taglib," which is one of Jakarta Taglibs's offerings. This distribution is separate from Tomcat and all other products; it's a sample WAR and a set of JARs.
Hope that helps,

[Peter W Smith]

Shawn,
Do you know any web design tools that support the tag libs? I mean sth like "drag & drop" to combine HTML stuff with the tags?
thanks,
Peter

[Sarada Bhasker]

As a technology how extensively JSTL is used in the industry?

[Peter W Smith]

Does anyone know whether there is a tag for downloading files under some directory on the server?

[Shawn Bayern]

Answers to a few questions:

Do you know any web design tools that support the tag libs? I mean sth like "drag & drop" to combine HTML stuff with the tags?

Macromedia UltraDev has some open-source extensions that work with tag libraries, and I believe the new Sun ONE Studio also offers (or intends to offer) support for tag libraries. For an UltraDev extension for taglibs, see http://jakarta.apache.org/taglibs

As a technology how extensively JSTL is used in the industry?

JSTL is brand new, just having been released a few months ago. Still, it has gained wide support in the industry, though these plans are still incipient. Many vendors of JSP and/or J2EE containers plan to bundle JSTL with their products, and JSTL gained almost universal support from the JCP executive committee.

Does anyone know whether there is a tag for downloading files under some directory on the server?

You can simply use the <c:import> tag to vend a file (use the 'file://' scheme), but for non-text files, you'll want to set a MIME type yourself; <c:import> does not handle that.
However, for non-text files, JSP isn't generally appropriate; it's better to use a Servlet, for JSP is primarily a textual medium.
Hope that helps!