struts-default package and benefits

struts-default package and benefits

In Struts2, the struts-default package is a built-in package provided by the framework. It is defined in the Struts2 core library and includes a collection of commonly used interceptors and result types. This package is intended to simplify the configuration process by providing a default set of functionalities that can be extended or overridden as needed.

struts-default package and benefits

Benefits of Using Struts-Default Package:

  • 1.  Convenience : Provides a pre-configured set of interceptors and result types, reducing the amount of configuration required.
  • 2.  Reusability : Common functionalities such as validation, file upload handling, and exception handling are included, making them easily reusable across actions.
  • 3.  Standardization : Promotes a standard way of configuring actions and interceptors, leading to more consistent code.
  • 4.  Extensibility : Developers can extend the struts-default package to add custom interceptors or result types while still leveraging the default functionalities.

Java Example

Let’s create a simple Struts2 application using the struts-default package.

Step 1: Configure Struts2 with the Default Package
xml
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
    <!-- Define a package that extends the struts-default package -->
    <package name="default" namespace="/" extends="struts-default">
        
        <!-- Define an action -->
        <action name="hello" class="com.example.action.HelloAction">
            <result name="success">/hello.jsp</result>
        </action>
    </package>
</struts>

Step 2: Create Struts2 Action
java
package com.example.action;

import com.opensymphony.xwork2.ActionSupport;

public class HelloAction extends ActionSupport {
    
    private String message;

    @Override
    public String execute() {
        message = "Hello, World!";
        return SUCCESS;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

Step 3: Create JSP Page
jsp
<%@ taglib uri="/struts-tags" prefix="s" %>
<html>
<head>
    <title>Hello</title>
</head>
<body>
    <h1><s:property value="message" /></h1>
</body>
</html>

Explanation of the Example

  • 1.  Configuration : The struts.xml file defines a package named default that extends struts-default. This means the package inherits all the interceptors and result types defined in struts-default.
  • 2.  Struts2 Action : HelloAction.java is a simple action that sets a greeting message.
  • 3.  JSP Page : hello.jsp displays the message set by HelloAction.

Benefits in the Example:

  • Convenience : By extending struts-default, we automatically inherit the default set of interceptors, which includes functionalities like parameter handling, validation, and exception handling.
  • Reusability : If we have other actions, they can also extend from the same default package, reusing the same set of interceptors and configurations.
  • Standardization : Using the struts-default package ensures that our configuration follows a standard structure, making it easier for other developers to understand and maintain.