What does struts do in java with example

Eudora 53 Published: 08/19/2024

What does struts do in java with example

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In Java, Struts is an open-source framework that enables the development of web applications based on the Model-View-Controller (MVC) pattern. It simplifies the process of building a web application by providing a consistent architecture and a set of APIs for handling HTTP requests and responses.

At its core, Struts provides a way to decouple the presentation layer from the business logic layer, allowing you to separate concerns and improve maintainability. Here's an overview of how Struts works:

Struts' Components

Action: This is the central component in Struts that handles HTTP requests. An Action maps incoming requests to specific business logic operations. FormBean: A FormBean encapsulates data validation, conversion, and formatting. It acts as an intermediary between the presentation layer (e.g., HTML forms) and the business logic layer (Action). Controller: This is responsible for managing the workflow of a Struts application by defining the mapping of Actions to URLs. Interceptor: Interceptors are small programs that execute before or after certain events in a Struts application, allowing you to perform tasks such as security checks, logging, and caching.

Example: A Simple "Hello World" Application

Let's create a simple Struts application that displays a welcome message. We'll have an Action called HelloAction that handles the request and returns a response:

public class HelloAction extends Action {
public ActionForward execute(ActionMapping mapping, HttpServletRequest request,
HttpServletResponse response) throws Exception {
// Return a "Hello World!" message as the result
return new ForwardAction("/hello.jsp");
}
}

In this example, HelloAction maps to a specific URL and responds with a JSP (JavaServer Pages) file that displays the welcome message.

How Struts Works

Here's what happens when you request /hello.do:

The web server receives the request for /hello.do. Struts' FrontController handles the request, looking up the mapping of URLs to Actions. It finds the HelloAction and calls its execute() method, passing the HTTP request and response objects as arguments. The HelloAction performs the business logic operation (in this case, simply returning a welcome message). Struts' FrontController takes the result of the Action's execution and passes it to the next layer (the presentation layer) for rendering.

In this example, we would have a JSP file (hello.jsp) that would render the welcome message based on the result returned by HelloAction.

Key Takeaways

Struts simplifies web application development by providing a consistent architecture and APIs for handling HTTP requests and responses. Actions handle business logic operations, while FormBeans manage data validation, conversion, and formatting. Interceptors allow you to perform tasks such as security checks, logging, and caching.

This is just the beginning of your Struts journey. With its powerful framework, you can build scalable, maintainable, and efficient web applications using Java!

What is the action of Struts in Java?

I apologize for the initial instruction to respond in Simplified Chinese. Here's my attempt to answer your question in English:

Struts is an open-source web application framework written in Java that enables developers to build scalable, maintainable, and reusable applications more efficiently. Introduced by The Apache Software Foundation in 2000, Struts provides a comprehensive architecture for building enterprise-level applications.

The primary action of Struts lies in its ability to simplify the process of developing web-based applications. It does this by providing a set of pre-built components (known as "actions") that can be easily integrated into an application's workflow. These actions facilitate communication between the client-side (the browser) and server-side (the Java code) of a web application.

Here's how Struts works:

Request-Response Cycle: When a user interacts with a web page, they initiate a request that is sent to the web server. The server then invokes a specific action in the Struts framework. Action Mapping: Struts maintains an XML-based configuration file (struts-config.xml) that maps URLs to actions. This mapping ensures that incoming requests are routed to the correct action for processing.

Action Invocation: When an action is invoked, it performs specific logic and data manipulation tasks. These can include database interactions, business logic, or even calling other Java classes. View Rendering: After processing, the action generates a response (typically in the form of HTML) that is sent back to the client's browser.

Struts provides numerous benefits for developers:

Faster Development: Struts simplifies the development process by providing pre-built actions and templates, reducing the time required to build an application. Easier Maintenance: With its modular architecture, Struts enables easy modification of individual components without affecting the entire application. Improved Reusability: Struts actions can be reused across multiple applications, promoting code reuse and efficiency. Support for Multiple Frontends: Struts allows developers to integrate different frontend technologies (e.g., JSP, Velocity, or Freemarker) into their application.

Although Struts has been largely replaced by more modern frameworks like Spring MVC, Hibernate, and Vaadin, its legacy remains as a pioneering framework that significantly influenced the development of web applications in Java.