Programming Jakarta Struts, 2nd Edition [Electronic resources] نسخه متنی

A.6 New Features of Struts 1.1

The new features in
Version 1.1 of the Struts
framework are covered in detail throughout this book. Descriptions of
the most important ones are provided here.

A.6.1 Declarative Exception Handling

Prior to 1.1, exception handling was left up to the application.
There was no support for it in the core framework, and developers
were left to their own devices to figure out how to handle exceptions
within an application.

Starting with 1.1, exception handling is now part of the core
framework. You can declaratively configure which exceptions actions
can throw and what should happen when they occur. Chapter 10 covers exception handling in detail and
includes details about this declarative methodology.

A.6.2 Dynamic ActionForms

A new type of ActionForm class was added in 1.1,
and broader support for it has been added throughout the entire
framework. The DynaActionForm and its subclasses
allow you to configure form-bean instances in the Struts
configuration file. This saves development time because you are no
longer required to create ActionForm classes.

It's a little too general to say that you'll never need to create another ActionForm classhowever, the number of them that you need to create should be drastically reduced.

See Chapter 7 for more information on this new
feature.

A.6.3 Plug-ins

The PlugIn feature was added to the Struts
framework to provide a mechanism to notify and initialize services
when the Struts application starts up and shuts down. There is a wide
range of possibilities for this feature, and in fact, the Struts
Validator and the Tiles library both take advantage the
PlugIn mechanism. See Chapter 9 for more information on using plug-ins in
your applications.

A.6.4 Multiple Application Modules

The addition of application modules to the framework allows a single
Struts application to support more than one Struts configuration
file. This facilitates a project being divided into subprojects, each
with its own configuration file. While this might sound more
complicated, it allows better support for parallel development.

The support for multiple application modules is still undergoing some
changes and modifications. At the time of this writing, you can use
extension mapping only for the controller servlet, and it may be a
while before the rest of the components have full support for this
new feature.

A.6.5 Nested Tags

Nested tags are a set of JSP custom tags that were added to the
Struts framework to give developers better control over accessing
properties from a JavaBeans object graph. Many JavaBeans objects
contain nested JavaBeans objects that can be referenced by the parent
bean. For example, a Customer object may hold a reference to an
Address object. To better support the nested nature of these
JavaBeans in the Struts views, the nested tags were created. The tags
within the Nested tag library are discussed in
Chapter 7.