Hello World Example using Stuts2

Last Updated : 31 Jul, 2022

Apache Struts 2 is an open-source web application framework for developing Java EE web applications. It uses and extends the Java Servlet API to encourage developers to adopt a model–view–controller architecture. In this article, we will see how we can create a simple Hello World application in Struts 2. We are going to use Eclipse IDE so that all the required components will be created under a Dynamic Web Project.

Prerequisites:

Before creating your Struts2 project it is important to make sure that you have the Apache Tomcat server installed and configured with the Eclipse IDE.
Create a dynamic web project and set it up with the struts2 framework. Refer to “Create and Setup Struts2 Dynamic Web Application in Eclipse” for the same.

Now, if the above conditions are fulfilled and your web application is configured with the struts2 then follow the steps given below.

Step by Step Implementation

1] web.xml file

Create a web.xml file under the webapp/WEB-INF folder and copy the following code in web.xml. This file is created by default if you have checked the Generate web.xml deployment descriptor option at the time of creating a dynamic web project. Now copy the following code in the web.xml file.

XML

<?xml version="1.0" encoding="UTF-8"?> 
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
        xmlns="http://xmlns.jcp.org/xml/ns/javaee" 
        xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee  
        http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"  
        id="WebApp_ID" version="4.0"> 
    
  <display-name>Struts2 Hello World Example</display-name> 
    
  <welcome-file-list> 
    <welcome-file>login.jsp</welcome-file> 
  </welcome-file-list> 
    
  <filter> 
      <filter-name>struts2</filter-name> 
      <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class> 
  </filter> 
    
  <filter-mapping> 
      <filter-name>struts2</filter-name> 
      <url-pattern>/*</url-pattern> 
  </filter-mapping> 
    
</web-app>

2] Result Pages

We need JSP pages to display the final result, this page will be called by the Struts 2 framework where a predefined action will be called and this mapping is defined in the struts.xml file. We are using Struts 2 UI tags to create our JSP pages. To create a JSP file, right-click on the webapp folder in the project explorer and select New >JSP File. Refer to the below image

login.jsp file

A JSP login page to display the username and password input fields and submit button. Copy the following code into the login.jsp file.

HTML

<%@ page language="java" contentType="text/html; charset=UTF-8" 
    pageEncoding="UTF-8"%> 
<%@taglib uri="/struts-tags" prefix="s" %> 
  
<!DOCTYPE html> 
<html> 
<head> 
    <meta charset="UTF-8"> 
    <title>Login Page</title> 
</head> 
  
<body bgColor="lightBlue"> 
    <s:form action="Welcome"> 
        <s:textfield name="userName" label="User Name" /> 
        <s:password name="password" label="Password" /> 
        <s:submit value="Say Hello" /> 
    </s:form> 
</body> 
</html> 

welcome.jsp file

Create a welcome.jsp file under the webapp folder. This file displays a welcome message to the user. Copy the following code into the file.

HTML

<%@ page language="java" contentType="text/html; charset=UTF-8" 
    pageEncoding="UTF-8"%> 
<%@taglib uri="/struts-tags" prefix="s" %> 
  
<!DOCTYPE html> 
<html> 
<head> 
    <meta charset="UTF-8"> 
    <title>Welcome Page</title> 
</head> 
  
<body> 
    <h2> Hello World Example in Struts 2</h2> 
    <h3> Hello <s:property value="userName"/> !!! </h3> 
</body> 
  
</html>

3] Action class: WelcomeAction.java

A Struts2 Action class is used to declare all the business logic inside. Our application has only one Action class whereas our WelcomeAction class extends ActionSupport class. It is good to extend ActionSupport class as it provides a default implementation for most common tasks. Create a WelcomeAction.java file and Copy the following code into the file.

Java

package com.GeeksforGeeks.struts2; 
  
import com.opensymphony.xwork2.ActionSupport; 
  
public class WelcomeAction extends ActionSupport { 
   
    // Java bean to hold the form parameters 
    private String userName; 
   
    public String getUserName() { 
        return userName; 
    } 
   
    public void setUserName(String userName) { 
        this.userName = userName; 
    } 
      
    // All struts logic goes here 
    public String execute() { 
        return SUCCESS; 
    } 
  
}

4] Struts configuration file: struts.xml

We need a mapping between URL to action mapping. The struts.xml maps the WelcomeAction class, and the welcome.jsp together. The mapping tells the Struts 2 framework which class will respond to the user’s action (the URL), which method of that class will be executed, and what view to render based on the String result that method returns. So we will now create a struts.xml file under the src/main/java folder. Copy the following code into struts.xml:

XML

<?xml version="1.0" encoding="UTF-8" ?> 
  
<!DOCTYPE struts PUBLIC 
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" 
    "http://struts.apache.org/dtds/struts-2.0.dtd"> 
      
<struts> 
  
    <constant name="struts.custom.i18n.resources" value="WelcomeAction" /> 
    
    <package name="default" extends="struts-default" namespace="/"> 
        <action name="Welcome" class="com.GeeksforGeeks.struts2.WelcomeAction" > 
            <result name="success">welcome.jsp</result> 
            <result name="input">login.jsp</result> 
        </action> 
    </package> 
      
</struts> 