Java Reference
In-Depth Information
L
ISTING
19.6
Continued
// used by the parent tag.
// This is just good practice for when you start creating
// hierarchies of tags.
super.release();
// Reset the name to an empty String
name = new String();
}
}
There are only a couple of new things to notice here. The first is the
name
attribute and the
setName()
method. This is the attribute/method matching that is used to set attribute values as
we discussed earlier. The class level attribute name is prepended with
set
and the first letter of
the attribute is capitalized to perform this matching.
To deploy this new tag you need to add an entry to the
tld
, compile the
HelloAttributeTag
,
and move the class file to the
<SERVER_ROOT>/webapps/djs/WEB-INF/classes/com/djs/
directory. The code snippet that needs to be added to the tld follows:
<tag>
<name>helloAttribute</name>
<tagclass>com.djs.HelloAttributeTag</tagclass>
<bodycontent>JSP</bodycontent>
<info>Just Says Hello to the Body</info>
<attribute>
<name>name</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
</tag>
The only real change to this
tag
element is the addition of the
attribute
element. In this ele-
ment you state three things. You first name the attribute, which is
name
for this tag. You then
state whether the attribute is required. This can be either
true
or
false
. The final addition to
the
attribute
element is the
rtexprvalue
element. This states whether the value of the
attribute can be an evaluated expression. The options are
true
or
false
.
To see this tag in action, use the JSP found in Listing 19.7.
L
ISTING
19.7
HelloAttribute.jsp
<%@ taglib uri=”/djs” prefix=”djs” %>
<html>
<body>
