Dinesh on Java

Struts2

Struts 2 param Tag Example

In this tutorial, We will discuss about the param tag in struts 2.
This tag can be used to parameterize other tags. The parameters can be added with or without a name as key. when we declare the param tag, the value can be defined in either a value attribute or as text between the start and end tag. Struts behaves a bit different according to these two situations.

This tag has the following two parameters.

name (String) – the name of the parameter
value (Object) – the value of the parameter

The following Example will shows how to implement the ParamTag in the Struts2-
First we create a JSP file named success.jsp as follows.

<%@ page contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
<head>
<title>Action Data Tag Struts2 | dineshonjava.com</title>
</head>
<body>
   <h2>An example of the param tag: </h2>
   <s:bean name="com.dineshonjava.struts2.action.DataTagAction" var="paramTag">
  <s:param name="userName">Dinesh Rajput</s:param>
  <s:param name="userAge">27</s:param>
  <s:param name="userPhone">9998851234</s:param>
  <s:param name="userAddress">ABC Noida</s:param>
 </s:bean>
 
 <ol>
  <li>User Name : <s:property value="#paramTag.userName" /></li>
  <li>User Age : <s:property value="#paramTag.userAge" /></li>
  <li>User Phone : <s:property value="#paramTag.userPhone" /></li>
  <li>User Address : <s:property value="#paramTag.userAddress" /></li>
 </ol>
</body>
</html>

Configuration file in struts 2.
struts.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.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="false" />
    <constant name="struts.custom.i18n.resources" value="myapp" />
 
 <package name="default" extends="struts-default" namespace="/">
        <action name="paramtag" class="com.dineshonjava.struts2.action.DataTagAction">
            <result name="success">/success.jsp</result>
        </action>
    </package>
 </struts>

Create Action class

package com.dineshonjava.struts2.action;

import com.opensymphony.xwork2.ActionSupport;

/**
 * @author Dinesh Rajput
 *
 */
public class DataTagAction extends ActionSupport {

 private static final long serialVersionUID = -7744420104547018874L;
 
 private String userName;
 private String userAge;
 private String userPhone;
 private String userAddress;
 
 public String execute() {
  return SUCCESS;
 }
 
 public String sayHello() {
  return SUCCESS;
 }
 
 public String getUserName() {
  return userName;
 }

 public void setUserName(String userName) {
  this.userName = userName;
 }

 public String getUserAge() {
  return userAge;
 }

 public void setUserAge(String userAge) {
  this.userAge = userAge;
 }

 public String getUserPhone() {
  return userPhone;
 }

 public void setUserPhone(String userPhone) {
  this.userPhone = userPhone;
 }

 public String getUserAddress() {
  return userAddress;
 }

 public void setUserAddress(String userAddress) {
  this.userAddress = userAddress;
 }
 
}

Your web.xml should look like:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>Struts2DataTag</display-name>
 <filter>
        <filter-name>struts2</filter-name>
        <filter-class>
            org.apache.struts2.dispatcher.FilterDispatcher
        </filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

Right click on the project name and click Export > WAR File to create a War file. Then deploy this WAR in the Tomcat’s webapps directory. Finally, start Tomcat server and try to access

URL http://localhost:8080/doj/paramtag.

This will give you following screen:

Download SourceCode
ParamDataTagExample.zip

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Dinesh Rajput

Dinesh Rajput is the chief editor of a website Dineshonjava, a technical blog dedicated to the Spring and Java technologies. It has a series of articles related to Java technologies. Dinesh has been a Spring enthusiast since 2008 and is a Pivotal Certified Spring Professional, an author of a book Spring 5 Design Pattern, and a blogger. He has more than 10 years of experience with different aspects of Spring and Java design and development. His core expertise lies in the latest version of Spring Framework, Spring Boot, Spring Security, creating REST APIs, Microservice Architecture, Reactive Pattern, Spring AOP, Design Patterns, Struts, Hibernate, Web Services, Spring Batch, Cassandra, MongoDB, and Web Application Design and Architecture. He is currently working as a technology manager at a leading product and web development company. He worked as a developer and tech lead at the Bennett, Coleman & Co. Ltd and was the first developer in his previous company, Paytm. Dinesh is passionate about the latest Java technologies and loves to write technical blogs related to it. He is a very active member of the Java and Spring community on different forums. When it comes to the Spring Framework and Java, Dinesh tops the list!