JavaServer Pages, 3rd Edition

Differences Between a JSP 1.2 and a JSP 2.0 TLD

A JSP 2.0 container is required to accept a TLD in the JSP 1.1 or 1.2 format, but you must use the new JSP 2.0 format in order to take advantage of the new features, such as tag files and functions.

Some of the differences between the JSP 1.2 and JSP 2.0 TLD file format are due to the fact that JSP 2.0 uses XML Schema for declaration (and validation) of the elements while JSP 1.2 used a Document Type Definition (DTD) for the same purpose. The switch to XML Schema applies to all descriptor files in the specifications grouped under the J2EE 1.4 umbrella, allowing for shared type definitions and grouping rules for the elements they have in common. The following differences can be attributed to the switch to XML Schema:

• The namespace and schema declarations in the <taglib> root element replace the DTD DOCTYPE declaration, for consistency with all other J2EE 1.4 configuration files.

• The <jsp-version> element is replaced by the version attribute in the <taglib> root element.

• The order and grouping of the description elements are changed: the <description> and <display-name> elements have switched places and an <icon> element has been added to contain the <small-icon> and <large-icon> elements. This group of elements now also always appear as the first nested elements where they are supported; in the JSP 1.2 spec they were sometimes included in the middle of more specific elements.

• The <body-content> element is mandatory, because the default used ...