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 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
