In Apache Struts based web applications, what is DispatchAction and how is it used to handle multiple related actions from a single controller class?

Introduction / Context:

Apache Struts is a Java based web framework that follows the Model View Controller pattern. In classic Struts applications, developers often need to handle several closely related user operations, such as add, update, and delete, for the same screen. DispatchAction is a convenience mechanism that allows grouping these operations in a single controller class instead of creating many separate action classes.

Given Data / Assumptions:

• We are working with Struts 1 style applications that use Action classes.
• Different buttons or links on a page perform related operations on the same domain object.
• A request parameter is used to decide which method should run inside the DispatchAction class.

Concept / Approach:

DispatchAction is a special Struts base class that extends Action. Instead of overriding a single execute method, the developer defines multiple public methods inside the same class, each representing a logical action such as add, edit, or delete. In the Struts configuration, a parameter name is specified. When a request arrives, Struts reads this parameter value and looks for a method with the same name in the DispatchAction class. It then dispatches the call to that method. This reduces the number of separate Action classes and keeps related operations together, improving organization and maintainability.

Step-by-Step Solution:

Verification / Alternative check:

Struts reference documentation and tutorials show examples where a form has several buttons, each with a different name such as method=add or method=update. The ActionMapping specifies parameter=method for the DispatchAction. When a user clicks a button, the corresponding method in the DispatchAction class is invoked. This behaviour matches the description in the correct option and confirms that DispatchAction is about dispatching to methods based on request parameters.

Why Other Options Are Wrong:

Common Pitfalls:

One pitfall is putting too many unrelated methods into a single DispatchAction, which can create a large controller that is hard to maintain. Another issue is forgetting to validate the parameter value, which can lead to confusion if the requested method does not exist. Developers must also be careful to keep method names descriptive and to group only closely related actions inside the same class. In modern frameworks, similar ideas appear as controller classes with multiple handler methods mapped by annotations or routes.

Final Answer:

The correct choice is DispatchAction is a Struts action class that lets one controller method handle different logical actions based on a request parameter, so related operations can be grouped in a single class. because this explanation accurately captures the purpose and usage of DispatchAction in Struts based web applications.