JavaServer Pages, 3rd Edition

Declaring Files as JSP Documents

As I will show you later in this chapter, JSP pages can be written as well-formed XML documents, using a slightly different syntax for things like tag library declarations and other directives than what you’ve seen so far. The default extension for a JSP page in the XML format is .jspx, starting with the JSP 2.0 specification. To make it possible to use other extensions, and to allow applications that use this extension for regular JSP files, the <is-xml> element can be used to control whether a file should be processed as a JSP page in XML format:

<web-app ...>
  ...
  <jsp-config>
    <jsp-property-group>
      <url-pattern>*.jspx</url-pattern>
      <is-xml>false</is-xml>
    </jsp-property-grop>
    <jsp-property-group>
      <url-pattern>*.svg</url-pattern>
      <is-xml>true</is-xml>
    </jsp-property-grop>
  </jsp-config>
  ...
</web-app>

As with EL evaluations, the default for this property depends on which version of the servlet specification the application’s deployment descriptor adheres to, in order to guarantee backward compatibility. If the application has a pre-2.4 deployment descriptor, the .jspx extension means nothing special; files with this extension are not considered to be JSP pages at all. For an application with a 2.4 deployment descriptor, files with a .jspx extension are processed as JSP XML pages by default.

The deployment descriptor snippet shown here defines two JSP groups. The first one disables the .jspx default extension, so that files with this extension are instead ...