Question

I don’t want to change the java code whenever there is addition of tag if the business logic will be remain same. I can access it by using Enumeration set of attributes(request.getAttributeNames()).

e.g.

<car:built
 maker="ford" wheel="four" name="endeavor" engine="dohc" power="72bhp"
 tyre="4" interior="mobile-charger,cigratte-lighter, music player"
 />

Rather than doing comma separated the interior, i wish to add in following way:

<car:built maker="ford" wheel="four" name="endeavor" engine="dohc" power="72bhp"
tyre="4" interior-mobile-charger="true" interior-cigratte-lighter="true" 
interior-music-player-maker="JVC"  interior-music player-bass="true"/>

So that, i can iterate and check whether attribute name contains "interior" word and store in a map and send it to the reports. It can also help me to define new attribute without changing the java code.

Is there any way to create custom attribute in jsp tag library without defining setter method?

Answer 1

What you’re looking for is called “dynamic attributes”.

See this previous question to see how to do it:

Problem in interpreting dynamic attributes in Jsp

Essentially, you add

<dynamic-attributes>true</dynamic-attributes>

To the .tld descriptor, indicating that any old attributes can be passed to the tag. Your tag class must then implement the DynamicAttributes interface, and the undeclared attributes will be passed in to your tag as a map:

For a tag to declare that it accepts
dynamic attributes, it must implement
this interface. The entry for the tag
in the Tag Library Descriptor must
also be configured to indicate dynamic
attributes are accepted.

For any attribute that is not declared
in the Tag Library Descriptor for this
tag, instead of getting an error at
translation time, the
setDynamicAttribute() method is
called, with the name and value of the
attribute. It is the responsibility of
the tag to remember the names and
values of the dynamic attributes.