Include
Includes the contents of another file. The file is included dynamically
(at page run time) so if the file to be included is modified, the
modifications are seen instantly.
Internally, a servlet RequestDispatcher is used to include the file. If
a included file name is absolute (begins with a '/'), then it is relative
to the servlet webapp, otherwiser it is relative to the current page.
If you want to send additional parameters to the included page,
see more detail.
The RequestDispatcher (used to dynamically include the file) is obtained from the HttpServletRequest.
As of writing (Servlet 2.5), this means additional parameters attached
to the include file URL are ignored by the servlet engine.
[include "file.mp?greeting=hello"]
The included file (file.mp in this example) will return
null for
request.getParameter("greeting"). The
fix for this is:
[[ req.setAttribute("greeting", "hello"); ]]
[include "file.mp"]
Now, in the included file (file.mp), one can say
request.getAttribute("greeting") and this will return
hello.
Syntax
Include sections can appear anywhere in text sections.
[include filename ]
Quotes around the filename are optional.
The name of the included file can contain expressions
and hence be generated dynamically. For example:
[[ int i = 3; ]]
[include 'foo[=i].html' ]
will include a file called foo3.html in the page.
Tag-Escape
To prevent the tag from being recognized, this tag can be escaped by
prefixing the start tag with a backslash: \[include
Example
An simple example of a conditional include (for illustrative purposes only).
<![CDATA[<html>
<body>
[[
String include_file_name =
req.getParameter("name") + ".header";
]]
[include '[=include_file_name]' ]
</body>
</html>
]]>
this is the admin.header
this is the user.header