1.4.4

Fixed Template Data

Fixed template data

 is used to describe those pieces that are to be used 

verbatim

 either in the 

response or as input to JSP actions. For example, if the JSP page is creating a presentation in 

HTML of a list of, say, books that match some search conditions, the template data may 

include things like the 

,

, and something like 

The following book

...

This fixed template data is written (in lexical order) unchanged onto the output stream 

(referenced by the implicit 

out

 variable) of the response to the requesting client.

1.4.5

Directives and Actions

There may be two types of 

elements 

in a JSP page: 

directives

 or 

actions

. 

Directives

 provide 

global information that is conceptually valid independent of any specific request received by 

the JSP page. For example, a directive can be used to indicate the scripting language to use 

in a JSP page. 

Actions

 may, and often will, depend on the details of the specific request 

received by the JSP page. If a JSP container uses a compiler or translator, the directives can 

be seen as providing information for the compilation/translation phase, while actions are 

information for the subsequent request processing phase.

An action may create some 

objects

 and may make them available to the scripting elements 

through some 

scripting specific variables.

Directive elements have a syntax of the form

<%@ directive ...%>

Action elements follow the syntax of XML elements, i.e. have a start tag, a body and an end 

tag:

 body

or an empty tag

An element has an 

element type 

describing its tag name, its valid attributes and its semantics; 

we refer to the type by its tag name.

Tag Extension Mechanism

An element type abstracts some functionality by defining a specialized (sub)language that 

allows more natural expression of the tasks desired, can be read and written more easily by 

tools and also can even contribute specialized yet portable tool support to create them. 

25

JavaServer Pages 1.1 Specification   November 30, 1999