Jsp-faq (1)

JS Java Server Pages Frequently asked Questions


Maintainer:richard Vowles, rvowles@esperanto.org.nz (http://www.esperanto.org.nz)



Questions
What is JSP?
What version is the current version of JSP?
Where can I get the specification for JSP?
Who supports JSP?
What books are available for JSP?
is JSP better than ASP (Microsoft ' s Active Server Pages)?
What HTML editors support JSP?
Yes, but how does it perform?
How do I invoke a JSP page directly from by browser?
How do I invoke a JSP page from a servlet?
How do I pass data (including beans) to a JSP from a servlet?
How can I pool connections to my database?
How does I use the other languages into my JSP?
How can I set a cookies in JSP?
Can JSP and Servlet share same session and Beans?
How does I plug JSP into Microsoft's IIS Web Server?
Are there any newsgroups that discuss JSP?
What do the differing levels of beans storage (page, session, app) mean?
Where can I find the mailing list archives?
What are the important steps in using JDBC in JSP?
How to does variable scope work in JSP?
How does I forward to an HTML page?
Are there any white papers or documents explaining how JSP fits?
How do I create dynamic GIFs for my JSP?
Do you know where I could get some code this would encode something to the HTML DTD standard?
What is page compilation?
How are servlets and JSP pages related?
Any good web sites for up to date activities into the Java/jsp/servlet world?
How does I force a user to log in?
So, can a newbie get started with JSP?
How can I ensure this session objects stay in existence when the Web server restarts?
How can I include one JSP inside another JSP?
Is there some sort of event this happens when a session object gets bound or unbound to the session?
Are there a way to execute a JSP from the comandline or from my own application?
What should I use, model 1 or Model 2?
How do I delete a cookies with JSP?
Are there tips on things to watch out as in JSP?
How do I get started with JSPs on the Macintosh?
What application Servers support JSP?
What happened to the LOOP and DISPLAY tags from JSP 0.92?
Does JSP have a bean providing File Upload features like ActiveX Upload control?
So, do I use the EJB from JSP?
Can I just abort processing a JSP?
"I ' m trying to" a "between" a servlet and a JSP page, but the I-am NULL on the JSP page. What could be wrong? "




1) What is JSP? Toc


JSP is a dynamic scripting capability of Web pages that allows Java as as a few special tags to be embedded into a W EB file (html/xml, etc). The suffix traditionally ends with. JSP to indicate to the Web server, the file is a JSP file. JSP is a server side technology-you can ' t does any client side validation with it.

JSP files actually get compiled to Servlets, so what are the point? Why not just write servlets?

For most people, the benefit is twofold:

The focus are on HTML. Java and the JSP extensions assist in making HTML more
Functional. Servlets on the other hand allow outputting of HTML but it is a tedious
Process.
It is easy to make a change and then let the JSP capability the Web Server for you are
Using deal with compiling it into a Servlet and running it.
In the past, people have used servlets because of the problem of Redirection-because to the time the JSP engine gets und to writing information on the HTTP pipe, you could does a redirect effectively to the jsp-leading TS of Model 1 vs Model 2 (question 38). This is the has been fixed in JSP 1.0 with the addition of buffered output streams.

JavaSoft also has a FAQ, covering different questions, and it is located at http://java.sun.com/products/jsp/faq.html.

2) What version is the current version of JSP? Toc



The current version of JSP is 1.1. It is available from http://java.sun.com/products/jsp.

The JSP 1.1 is available from http://java.sun.com/products/jsp/techinfo.html.

The 0.92 spec is available from http://java.sun.com/products/jsp/jsp092.html

The 0.91 spec is a popular version though, and much software that supports the JSP Pre-standard actually supports 0.91 of Jsp.

The 0.91 spec is available from http://www.burridge.net/jsp/Spec91/jsp_spec.html

3 Where can I get the specification for JSP? Toc



You can get the "current spec" from http://java.sun.com/products/jsp. This is along with the reference implementation which works with its own web server.

4 who supports JSP? Toc



There are the following implementations available:

Name
Version of JSP supported
Cost
Comments
JSP Reference 1.1 free Tomcat-now included as part of the Java EE Reference implementation, but also managed by the Jakarta Project as part of Apache. This implementation has a way to go before being ready for production.
GNU JSP 1.0 free, open source, located in CVS on Giant Java tree
Sun ' s Java Web Server 2.0 1.0 commercial Sun ' s own Java Web server. Being replaced with IPlanet (Alliance)
polyjsp 0.92 free, open source polyjsp are based on xml/xsl and has been to be designed. Now supports WEBL hasn ' t been updated to a while.
Resin 1.0, 1.1 in beta Unknown now Open Source.
SJSP 1.1 free for personal with Uses compile time introspection, allows your to replace your existing JSP engine in your web Server.
zjsp 0.91 Last updated, Sept 3, 1998
JRUN 0.92, 1.0 commercial JSP 1.1 support now in beta.
Orion 1.1 Commercial Orion is a Web application server that implements JSP internally. It also has a lot of JSP vs other JSP and vs ASP stats in its pages. Also supports Servlet 2.2
Servletexec 1.1 Commercial Supports large number of Web servers
ROCKETJSP 1.0 GPL located in the Giant Java tree




5) What books are available for JSP? Toc



There are now a number of books available in JSP from various publishers.

A Quick search of Amazon comes up with

Professional Java Server programming:with servlets, JavaServer Pages (JSP), XML, Enterprise JavaBeans (EJB), JNDI, CORBA, Jini and JavaSpaces
Professional Java XML Programming with Servlets and JSP
Pure JSP Java Server Pages
Web Development with JavaServer Pages
There is a group of people working in a Web book for Jsp-information are located at Http://www.esperanto.org.nz/jspbook. There is another in http://www.aptura.com/technology/jspBook_Architectures.html and yet another at Brainopolis.

6 is JSP better than ASP (Microsoft ' s Active Server Pages)? Toc



This is a matter of great debate. Many punters the JavaSoft has the benefit of hindsight-what works and what ' t. ASP is very complex but supports multiple scripting languages and the ActiveX model of Microsoft. Although ASP _is_ available on many platforms, the ActiveX library support that makes it as powerful as it's is missing a nd thus makes ActiveX only feasible to an NT platform.

According to recent statistics ("RedHat site"), 22% of Web servers are NT, (21% are Linux), that means there is 78% Needing something else, and JSP advocates believe that JSP fits the bill nicely so much.

7 What HTML editors support JSP? Toc



Most of the visual developers does not support JSP in any way, shape or form, they mess up the tags totally.

The following HTML editors have been known to work with JSP:


Product
Location
Comments
HomeSite Http://www.allaire.com/JSP Colour coding is in the HS 4.0.1, but you can get a plug into now from Http://www.burr Idge.net/jsp/homesite.html
NetObjects Scriptbuilder 3.0 http://www.netobjects.com/products/html/nsb3.html Win32 product supports JSP
Any text editor
Borland JBuilder 3.5 http://www.borland.com/jbuilder Java Development tool, supports JSP internally, and allows running an D Debugging of JSPs
DreamWeaver 3 Http://www.dreamweaver.com/Ignores JSP tags, and allows to edit JSP files as if they are HTML files giv En you customise the product slightly (for your need to edit a special file)
FrontPage Http://www.microsoft.com/frontpage Some reports that Front Page now ignores JSP tags.



8) Yes, but how does it perform? Toc



I have been picking up some comments:

Brian Burridge, Brian_burridge@VALPAK.COM
"Our extranets for-franchises, 500+ users, our Intranet for thousands of employees,
And eventually all of my other Web sites. New Atlanta has been running for 6 weeks
Now without even one problem. Programming in JSP has turned out to being as easy as Perl,
Yet all we tests show it to is up to 10x faster.
Also available are a set of benchmarks from the people who make the Orion server, located at http://orion.evermind.net/, a nd also from the people who does Resin (comparing their JSP implementation with Orion)

9 How do I invoke a JSP page directly from by browser? Toc



JSP files are just like HTML files, so if your index.jsp the file is into your root directory of your Web site, use http://local host/index.jsp