Struts <logic:lessThan> and <logic:lessEqual> Tag

The <logic:lessThan> tag evaluates if the requested variable is less than specific value. Whereas <logic:lessEqual> tag evaluates if the requested variable is less than equal to specific value. In order to use the Struts HTML Tags you need to include the following taglib directive in the jsp page.

<%@taglib uri="/WEB-INF/struts-html.tld" prefix="html" %> 

First create a new Dynamic Web Project and configure it as Maven Project. For Reference, Click Here

Add the following dependencies in pom.xml

<dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.8.2</version>
      <scope>test</scope>
    </dependency>
  
    <dependency>
      <groupId>org.apache.struts</groupId>
      <artifactId>struts-core</artifactId>
      <version>1.3.10</version>
    </dependency>
  
    <dependency>
      <groupId>org.apache.struts</groupId>
      <artifactId>struts-taglib</artifactId>
      <version>1.3.10</version>
    </dependency>
  
</dependencies>

1. Create DynaActionForm

First we create an entry for DynaActionForm in struts-config.xml

<form-beans>
    <form-bean name="EmployeeForm" 
        type="org.apache.struts.action.DynaActionForm">
        <form-property name="employeeId" type="java.lang.Integer" />
         <form-property name="employeeName" type="java.lang.String" />
         <form-property name="employeeAge" type="java.lang.Integer" />
    </form-bean>
</form-beans>

2. Action Class (Controller)

Let us create an Action class that will handle the request. Here Action Class contains the business logic.

EmployeeAction.java

package com.kruders.action;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.DynaActionForm;
 
public class EmployeeAction extends Action{
    public ActionForward execute(ActionMapping mapping,ActionForm form,
        HttpServletRequest request, HttpServletResponse response)
                throws Exception {
        DynaActionForm EmployeeForm = (DynaActionForm)form;
        EmployeeForm.set("employeeAge",25);
         
        return mapping.findForward("success");
    }
}

3. View

Create welcome.jsp and write the following code.

<%@taglib uri="http://struts.apache.org/tags-logic" prefix="logic"%>
<logic:forward name="checkLess" />

Now create another jsp file checkLess.jsp that contains the struts logic tag to check the requested variable is less than or less than equal to specific value.

<%@taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
<%@taglib uri="http://struts.apache.org/tags-logic" prefix="logic"%>
<%@taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
<html>
<head>
<title>Struts Logic Less Than Tag <logic:lessThan> and Less Equal Tag <logic:lessEqual></title>
</head>
<body>
 
<b>Struts - Check variable is less than or less than equal to specific value or not <logic:lessThan> and <logic:lessEqual></b><br>
<logic:lessThan name="EmployeeForm" property="employeeAge" value="30">
1st Case : Age is less than 30
</logic:lessThan>
 
<logic:lessEqual name="EmployeeForm" property="employeeAge" value="25">
<br>2nd Case : Age is less than equal to 25
</logic:lessEqual>
 
</body>
</html>

4. Struts Config

Add the following code in struts-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC 
"-//Apache Software Foundation//DTD Struts Configuration 1.3//EN" 
"http://jakarta.apache.org/struts/dtds/struts-config_1_3.dtd">
  
<struts-config>
    <form-beans>
        <form-bean name="EmployeeForm" 
            type="org.apache.struts.action.DynaActionForm">
            <form-property name="employeeId" type="java.lang.Integer" />
            <form-property name="employeeName" type="java.lang.String" />
            <form-property name="employeeAge" type="java.lang.Integer" />
        </form-bean>
    </form-beans>
    <global-forwards>
        <forward name="checkLess" path="/checkLess.do"/>
    </global-forwards>
       
    <action-mappings>
        <action input="/checkLess.jsp" name="EmployeeForm" path="/checkLess"  validate="true" scope="request" type="com.kruders.action.EmployeeAction">
            <forward name="success" path="/checkLess.jsp" />
        </action>
    </action-mappings>
</struts-config>

5. Deployment Descriptor

Now configure the deployment descriptor. Here, we have asked the container to give our ActionServlet any request that matches the pattern *.do

Add the following configuration information in the web.xml file

<welcome-file-list>
    <welcome-file>welcome.jsp</welcome-file>
</welcome-file-list>
 
<servlet>
    <servlet-class>
        org.apache.struts.action.ActionServlet
    </servlet-class>
    <init-param>
        <param-name>config</param-name>
        <param-value>/WEB-INF/struts-config.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>
  
<servlet-mapping>
    <servlet-name>action</servlet-name>
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

6. Run Project

Now when you run the project, following screen will be displayed as in Figure 35.1

Figure 35.1 Figure 35.1

The folder structure of the example is shown below in Figure 35.2

Figure 35.2 Figure 35.2

You can download the source code of this example here.

,

No comments yet.

Leave a Reply