JSP - FAQ (1)

By Donald Graham,2014-09-16 16:54
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JSP - FAQ (1)

    JSP - FAQ (1)


日期;2000-8-10 17:48:55

    Java Server Pages Frequently Asked Questions

    Maintainer: Richard Vowles, (


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 to invoke a JSP page directly from by browser?

How do you invoke a JSP page from a servlet?

    How do you pass data (including beans) to a JSP from a servlet?

How can I pool connections to my database?

How do I use other languages in my JSP?

How can I set a cookie in JSP?

Can JSP and Servlet share same Session and Beans?

How do I plug JSP into Microsoft's IIS Web Server?

Are there any newsgroups that discuss JSP?

    What do the differing levels of bean storage (page, session, app) mean?

Where can I find the mailing list archives?

What are the important steps in using JDBC in JSP?

How does variable scope work in JSP?

How do I forward to an HTML page?

    Are there any white papers or documents explaining how JSP fits?

How to I create dynamic GIFs for my JSP?

    Do you know where I could get some code that 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 in the

Java/JSP/Servlet world?

How do I force a user to log in?

So how can a newbie get started with JSP?

    How can I ensure that 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 that happens when a session

    object gets bound or unbound to the session?

    Is 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 cookie with JSP?

Are there tips on things to watch out for in JSP?

How do you get started with JSP 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 how do I use EJB from JSP?

Can I just abort processing a JSP?

    "I'm trying to pass an object between a servlet and a JSP page, but my object is null on the JSP page. What could be wrong?"

1) What is JSP? TOC

    JSP is a dynamic scripting capability for web pages that allows Java as well as a few special tags to be embedded into a web file (HTML/XML, etc). The suffix traditionally ends with .jsp to indicate to the web server that the file is a JSP file. JSP is a server side technology - you can't

    do any client side validation with it.

    JSP files actually get compiled into Servlets, so what is the point? Why not just write Servlets?

For most people, the benefit is twofold:

The focus is on HTML. Java and the JSP extensions assist in

    making the HTML more

    functional. Servlets on the other hand allow outputting of HTML but it is a tedious


    It is easy to make a change and then let the JSP capability of the Web Server 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 by the time the JSP engine gets around to writing information back down the HTTP pipe, you could not do a redirect effectively in JSP - leading to

    the concepts of Model 1 vs Model 2 (see question 38). This 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

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

    The current version of JSP is 1.1. It is available from

The JSP 1.1 is available from

The 0.92 spec is available from

    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

3) Where can I get the specification for JSP? TOC

You can get the current spec from is along with the

    reference implementation which works with its own web server.

4) Who supports JSP? TOC

There are the following implementations available:


Version of JSP Supported



    JSP Reference 1.1 free TOMCAT - Now included as part of the J2EE 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 at the 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 is based on XML/XSL and has been designed to be extensible. Now supports WebL

    Hasn't been updated for a while.

Resin 1.0, 1.1 in beta Unknown Now Open Source.

    SJSP 1.1 free for personal use Uses compile time introspection, allows you 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 on 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 on 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 on a Web book for JSP -

    information is located at is another at 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 think that JavaSoft has the benefit of hindsight - what works well and

    what does'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 is is missing and thus makes ActiveX only feasible for an NT platform.

    According to recent statistics (see the 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 that you very much.

7) What HTML editors support JSP? TOC

    Most of the visual developers do 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:




HomeSite colour coding will be

    in HS 4.0.1, but you can get a plug in now from

NetObjects ScriptBuilder 3.0

    product supports JSP

Any text editor

Borland JBuilder 3.5

    Development tool, supports JSP internally, and allows running and debugging of JSPs

DreamWeaver 3 JSP tags,

    and allows you to edit JSP files as if they are HTML files given you customise the product slightly (you need to edit a special file)

FrontPage 2000

    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 300 franchises, 500+ users, our Intranet for thousands of employees,

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