|
Dynamic Sites Development with ASP/JSP
JSP vs ASP
Introduction
5-6 years back it was easy to choose a server-side language as CGI used to be only the
only scripting language available. But in due course of time, the developers found out
that CGI scripts were inefficient and it was very difficult to write server extensions.
At that time, Microsoft came up with Active Server Pages (ASP), which allows developers to
use simple scripting to access the server and its extensions. But ASP had some
disadvantages. It limits you to work on Microsoft platforms, and the simplest of mistakes
in the script can cause the server to crash or hang, effectively bringing down your
website.
In response to ASP, Sun Microsystems gave the world Java Server Pages (JSP) technology,
which is entirely based on Java programming language. Internally, JSP pages are
dynamically converted into Servlets, which are simply Java classes. This means JSP enjoys
all the capabilities that Java programming supports.
JSP is a great deal more efficient than many other scripting languages, such as CGI and
ASP. Tags can be defined in tag libraries and then used within any JSP page. This makes
for a better separation of page content from its code, which leads to less scattered code
and hence, the site is easier to maintain. Global changes need to be made only to the tags
defined in these tag libraries, making time-consuming, page-by-page fixes things of the
past.
JSP versus ASP
JSP and ASP have some basic concepts in common.
1) They both make use of simple sever-side scripting to provide access to Web server
information and functionality.
2) They both have similar styles of delimiting this scripting from a page's content. In
fact, Microsoft's has recently come up with ASP+ is much more similar to JSP than ASP.
Yet while ASP primarily supports two scripting languages, JScript and VBScript, JSP
actually supports real Java code, not a new scripting language. The difference is that the
Java code inside a JSP page is more script-like because it doesn't require Java class and
package definitions. JScript, VBScript, and Java (in JSP) are all object oriented to some
degree as they are all provided with a set of pre-established objects by the Web server
that they use to generate a dynamic Web page.
The following table lists some of the instantiated objects that are available in both ASP
and JSP.
| JSP |
ASP |
Definition |
| Request |
Request |
Access to request
information. |
| Response |
Response |
Access to response
information. |
| Session |
Session |
Access to session
information. |
| Application |
Application |
Access to application
information. |
| Out |
Response.Write |
Access to the response
output stream |
Note that JSP is case sensitive. But
VBScript is not.
As I mentioned earlier, both ASP and JSP support a similar way of delimiting scripting
from content on a page. <% and %> are used to set of sections of script, '<%='
and '%>' are used to return a value within content, and <%@ and %> are used to
delimit page directives.
JSP supports two basic styles of delimiting its scripting elements from page content. The
first looks a great deal like ASP, whereas the second can be used to create JSP that is
fully XML compliant. Here, let's examine these styles:
Conclusion
In many ways, the biggest difference between JSP and ASP technologies lies in the approach
to the software design itself. JSP technology is designed to be both platform and server
independent, created with input from a broader community of tool, server, and database
vendors. In contrast, ASP is a Microsoft technology that relies primarily on Microsoft
technologies.
Now as we have seen the advantages of JSP over ASP, I'll like to share some information on
JSP with you:
" There are a number of servers that support JSP on the market. The popular ones are
Tomcat, Jrun and Enhydra.
" Another powerful feature of JSP that we haven't covered in this article is its
ability to utilize JavaBeans with special tags defined in JSP. For more information about
this, you can refer to Sun's JavaBean overview.
If you want to learn JSP, the best place to start is at the Sun Microsystems web site
(http://java.sun.com). Their support pages include the JSP specification and documentation
of the supporting Java classes. As you explore, make sure you get a good idea about the
underlying Java Servlet technology, since this is what all JSP must become behind the
scenes.
As you open up JSP and really see what it can do, you'll soon find that, with practice,
anyone (not just Java developers) can make use of the powerful set of tools that JSP
provides.
Useful Links
1) Java Server
Pages TM Fundamentals
2) ASP Tutorial
3) How JSP compares with ASP |
