Java Standard Tag Library (JSTL) Advantages

Java Standard Tag Library (JSTL) Advantages

JSTL, which stands for Java Server Pages Standard Tag Library, is a collection of custom JSP tag libraries that provide common Web development functionality. It was originally developed as the open source Apache Jakarta Taglib project but is now managed by the Java Community Process (JCP) under JSR-52 and Standard by Sun. JSTL's key goal was to remove the need for J2EE Web developers having to build their own proprietary tag libraries for common Web development processes.

The common Web development areas which JSTL covers include:

• Conditionals
  
• Iterations
• Text formatting
• Database access (SQL)
• XML processing
• Internationalization
• Accessing URL resources

Problems With Scriptlet
Java Server Pages Provide a way to develop presentation layer by merging static HTML code and dynamic Java Code using script. It is best as compared servlet but programmers or web developers who work on presentation layer mix java code.

1. Scriptlet code is not reusable--Scriptlet code appears in exactly one place: the JSP page that defines it.
2. Scriptlets encourage copy/paste coding--Because scriptlet code appears in only one place, it is often copied to a new context.
3. Custom tags centralize code in one place. When a tag handler class changes, the tag's behavior changes everywhere it is used.
4. Scriptlets mix logic with presentation-. Scriptlets can easily confuse the intent of a JSP page by expressing program logic within the presentation.
5. Scriptlets break developer role separation.
6. Scriptlets make JSP pages difficult to read and to maintain
7. Scriptlet compile errors can be difficult to interpret
8. Scriptlet code is difficult to test

<% if

((User)session.getAttribute("user")).getName().equals("test") {

%>

<% }

%>







<>test =" $ { user.name  = =  'test'

} " >

.......

<

/ c : i f >

 

JSP Standard Taglib

Library Advantages



1. Standard Tag

Once standardized, JSTL will provide a rich layer of portable

functionality to JSP pages.

It is easy for developer to

understand other code easily. Before Jstl every made his propriety tag

which are different for

every one now its standard and easy

to understand for all. It also is mature and tested.



 2.

Make Code Neat and Clean It makes the code neat and clean usually

scriplet confuse the developer due to mixing of java and html



code. it

makes clean the code



 3

.Automatic JavaBeans Introspection Support Here is

little advantage to JSTL over JSP scriptlets. But if you consider that

JSTL's

expression language handles JavaBean introspection

automatically.



 4.Easier

for Humans to Read JTSL is based on XML, which is very similar to HTML.

Rather than spending a great deal of time learning

where to

put semicolons and how to construct code blocks, HTML programmers can

fall right into a programming language that is similar to

HTML





5.Easier for Computers

to Read It is also much easier for computers to read. Tools such as

FrontPage and Dream weaver

are generating more and more HTML

code. Although HTML generation tools do a great job of formatting HTML

code, they often

run into problems when this HTML code is

intermixed with JSP scriptlet code. Because JSTL is always expressed in

XML-compliant tags,

it will be easier for HTML generation

tools to parse the JSTL code that is contained within the document

The above

are basic benefits of jstl

.JSTL introduce new way of

development and have lots of benefits in bits and

bytes level

I discussed only bytes level benefits it not easy to cover bites level

in this discussion but it is enough

for

understanding.