An element type indicates the name and type of such variables although details on the name 

of the variable may depend on the Scripting Language. The scripting language may also 

affect how different features of the object are exposed; for example, in the JavaBeans 

specification, properties are exposed via 

getter

 and 

setter

 methods, while these are available 

directly in the JavaScript

programming language.

The exact rules for the visibility of the variables are scripting language specific. Chapter 4 

defines the rules for when the 

language

 attribute of the 

page

 directive is  java .

1.4.8

Scripts, Actions, and Beans

Scripting elements, actions and Beans are all mechanisms that can be used to describe 

dynamic behavior in JSP pages. Different authors and authoring tools can use these 

mechanisms in different ways based on their needs and their preferences. The JSP 

specification does not restrict their use but this section provides some guidelines that may be 

useful to understand their relative strengths.

Beans are a well known and well supported component framework for the Java platform that 

can be accessed easily from the Java programming language and other JSP page scripting 

languages. Some JSP page authors, or their support organizations, may create or reuse Bean 

components to use from their JSP pages.

Actions provide an abstraction that can be used to easily encapsulate common actions. 

Actions typically create and / or act on (server side) objects, often Beans.

The JSP specification provides some standard actions that can be used to interact with any 

Bean. If the Bean is extended so it implements the 

Tag

 interface, then the Bean becomes a 

tag handler and it can be used directly in the JSP page with improved integration into the 

template data.

Scripting elements are very flexible; that is their power but also their danger as they can 

make hard understanding and maintain a page that uses them extensively; they may also 

make it hard for an authoring tool. In some development contexts, JSP pages will mostly 

contain only actions (standard or custom) with scripting elements only used as a  gluing  

mechanism that can be used to  fill in  the actions that are described using actions (and 

Beans and EJB components). In other development contexts JSP pages may contain 

significant amounts of scripting elements.

1.4.9

JSP, HTML, and XML

The JSP specification is designed to support the dynamic creation of several types of 

structured documents, especially those using HTML and XML.

27

JavaServer Pages 1.1 Specification   November 30, 1999