Custom Tag Library Declarations
Custom tag libraries are declared and associated with a prefix
through namespace declarations in a JSP Document. In Example 17-10, you see that the JSTL core tag library is
declared with an xmlns prefixed attribute in the
<c:forEach> element. As in XML, you can
declare all namespaces you need either in the root element or in
nested elements (where it applies only to that element and its
children). The custom tag library prefix is the part of the attribute
name following xmlns:, and the attribute value is
usually the URI for the library (as defined either in the
web.xml file or in the TLD file for the
library). That’s how the JSTL core library is
declared in Example 17-10. If you want to use the TLD
or JAR file path instead of a URI value, you must use a value
starting with urn:jsptld: followed by the path,
for instance:
<html xmlns:ora="urn:jsptld:/WEB-INF/lib/orataglib_3_0.jar" ...>
If the custom tag library consists of a set of tag files directly in
the web application structure (i.e., a library that you would
identify with the tagdir attribute of a
taglib directive in a regular JSP page), the value
must start with urn:jsptagdir:, followed by the
path to the directory:
<html xmlns:my="urn:jsptagdir:/WEB-INF/tags/mytags" ...>
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