Struts 2 param Tag Example

In this tutorial, We will discuss about the param tag in struts 2.
This tag can be used to parametrize 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



<<Previous <<   || Index ||   >>Next >>




No comments:

Post a Comment