Spring MVC Radiobutton And Radiobuttons Example

In this example, we will learn how to create multiple RadioButtons in a Simple Spring MVC Form using Spring tag library. We will learn how to use the <form:radiobutton> and <form:radiobuttons> tags and the difference between those two. Here we will create a Spring MVC form with multiple radiobuttons in which user selects his country and we will add validation support to check if the user atleast selects one country.

In Spring MVC we will use <form:radiobuttons> tag to render multiple radiobuttons

<form:radiobuttons items="${countryList}" path="country"></form:radiobuttons>

Which produces the below HTML code.

<span><input id="country1" name="country" type="radio" value="India"/><label for="country1">India</label></span>
<span><input id="country2" name="country" type="radio" value="England"/><label for="country2">England</label></span>
<span><input id="country3" name="country" type="radio" value="Australia"/><label for="country3">Australia</label></span>
<span><input id="country4" name="country" type="radio" value="South Africa"/><label for="country4">South Africa</label></span>

Folder Structure :

1. Create a Dynamic Web Project SpringMVCFormHandling and create a package for our src files “com.javainterviewpoint“
2. Place the Spring 3 jar files under WEB-INF/Lib 
   

   commons-logging-1.1.1.jar
   log4j-1.2.16.jar
   slf4j-api-1.7.5.jar
   slf4j-log4j12-1.7.5.jar
   hibernate-validator-4.2.0.Final.jar
   spring-aspects-3.2.4.RELEASE.jar
   spring-beans-3.2.4.RELEASE.jar
   spring-context-3.2.4.RELEASE.jar
   spring-core-3.2.4.RELEASE.jar
   spring-expression-3.2.4.RELEASE.jar
   spring-web-3.2.4.RELEASE.jar
   spring-webmvc-3.2.4.RELEASE.jar
   validation-api-1.1.0.Final.jar
   jstl-1.1.2.jar

3. Create the Java classes RadioButton_Controller.java and RadioButtonBean.java under  com.javainterviewpoint folder.
4. Place the SpringConfig-servlet.xml and web.xml  under the WEB-INF directory
5. View files SpringMVC_RadioButtonExample.jsp and radioButton_Success.jsp are put under the sub directory under WEB-INF/Jsp

Controller

RadioButton_Controller.java

• The DispatcherServlet mapping which we make in the web.xml will delegate the all the request to our RadioButton_Controller as we have annotated it with @Controller annotation.
• We use the @RequestMapping annotation to map each of the requests which we get to individual methods. Our controller has three methods getCountry(),initializeForm() and  processForm(). 
• The getCountry() method returns a list of country which will be used by view for populating the country radiobuttons.
• The initializeForm() will take the user to the “SpringMVC_RadioButtonExample” which is our view component with form backing object RadioButtonBean.
•  The processForm() method will get called when the user submits the form. The RadiButtonBean object “rb”  will be validated as we have annotated it with @Valid annotation and the validation results will be added to the BindingResult. Based on the result we will re-direct the user back to the “SpringMVC_RadioButtonExample” or “radioButton_Success” page.

Now lets see the difference between <form:radiobutton> and <form:radiobuttons>

If we use <form:radiobutton> then we have to hard-code each value for example

<form:radiobutton path="country" value="India"/>India
<form:radiobutton path="country" value="England"/>England
<form:radiobutton path="country" value="Australia"/>Australia
<form:radiobutton path="country" value="South Africa"/>South Africa

Where as when we use <form:radiobuttons> we can dynamically pass in a list to populate the radiobuttons.

<form:radiobuttons items="${countryList}" path="country"></form:radiobuttons>

Here we have passed in a list “favouriteList” which gets the value from the controller class.

package com.javainterviewpoint;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.validation.Valid;

import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class Radiobutton_Controller 
{
	@ModelAttribute("countryList")
	public List getCountry()
	{
		List countryList = new ArrayList();
		countryList.add("India");
		countryList.add("England");
		countryList.add("Australia");
		countryList.add("South Africa");
		
		return countryList;
	}
	
	@RequestMapping("/RadioButtonExample")
	public ModelAndView initializeForm(Map model)
	{
		return new ModelAndView("SpringMVC_RadioButtonExample","rb",new RadioButtonBean());		
	}
	
	@RequestMapping("/processRadioButtonForm")
	public String processForm(@Valid @ModelAttribute("rb")RadioButtonBean rb,BindingResult result)
	{
		if(result.hasErrors())
		{
			System.out.println("inside error block");
			return "SpringMVC_RadioButtonExample";
		}
		else
		{
			System.out.println("inside success block");
			return "radioButton_Success";
		}
	}
	
}

Model

RadioButtonBean.java

Here RadioButtonBean acts as a Model which has a country property. We have added the annotation @NotEmpty to validate if the user has atleast selected one country. The custom validation messages are added in the props.properties file.

package com.javainterviewpoint;

import org.hibernate.validator.constraints.NotEmpty;

public class RadioButtonBean 
{
	@NotEmpty
	String country;

	public String getCountry() {
		return country;
	}

	public void setCountry(String country) {
		this.country = country;
	}
	
	 
}

View

SpringMVC_RadioButtonExample.jsp

Our view component has multiple radiobuttons generated using the Spring form tag library. The radiobutton gets its value from our controller class. @ModelAttribute(“countryList”) of our controller will be called and it will return a list of country when  <form:radiobuttons items=”${countryList}” path=”country”/>  is called.<form:errors> tag displays the error message which occurs during the validation

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
 pageEncoding="ISO-8859-1"%>
 <%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<style>
.error {
 color: red;
 font-weight: bolder;
}
 
.commonerrorblock {
 color: #000;
 background-color: #ffEEEE;
 border: 3px solid #ff0000;
 
}
</style>
</head>
<body>
 <form:form method="post" action="processRadioButtonForm" commandName="rb">
 <form:errors path="*" element="div" cssClass="commonerrorblock"/>
 <table>
 <tr>
 <td>Country</td>
 <td>
 <form:radiobuttons items="${countryList}" path="country"></form:radiobuttons>
 </td>
 <td>
 <form:errors path="country" cssClass="error"/>
 </td>
 </tr>
 <tr>
 <td></td><td><input type="submit"></td>
 </tr>
 </table>
 </form:form>
</body>
</html>

props.properties

NotEmpty.rb.country = Please select a Country!!

RadioButton_Success.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
 pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
 <h2>Country Selected ${rb.country}</h2>
</body>
</html>

Configurations

web.xml

The web.xml has everything about the application that a server needs to know, which is placed under the WEB-INF directory. <servlet-name> contains the name of the SpringConfiguration, when the DispatcherServlet is initialized the framework will try to load a configuration file “[servlet-name]-servlet.xml” under the WEB-INF directory.

<?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_2_5.xsd"
	id="WebApp_ID" version="2.5">
	<display-name>SpringMVCFormHandling</display-name>
	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
		<welcome-file>index.htm</welcome-file>
		<welcome-file>index.jsp</welcome-file>
		<welcome-file>default.html</welcome-file>
		<welcome-file>default.htm</welcome-file>
		<welcome-file>default.jsp</welcome-file>
	</welcome-file-list>
	<servlet>
		<servlet-name>SpringConfig</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>SpringConfig</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

SpringConfig-servlet.xml

• The SpringConfig-servlet.xml is also placed under the WEB-INF directory.
• <context:component-scan> will let the Spring Container to search for all the annotation under the package “com.javainteriviewpoint”. 
• <mvc:annotation-driven/> annotation will activate the @Controller, @RequestMapping, @Valid etc annotations.
• The view is resolved through “org.springframework.web.servlet.view.InternalResourceViewResolver” which searches for the jsp files under the /WEB-INF/Jsp/ directory.
• Resource Bundle is accessed through the “org.springframework.context.support.ResourceBundleMessageSource”  through its property “basename” which has the value “props”, and hence our property file should “props.properties”

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation=" http://www.springframework.org/schema/beans	http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
 	http://www.springframework.org/schema/context	http://www.springframework.org/schema/context/spring-context-3.0.xsd
 	http://www.springframework.org/schema/mvc	http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

	<context:component-scan base-package="com.javainterviewpoint" />
	<mvc:annotation-driven />

	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/Jsp/" />
		<property name="suffix" value=".jsp" />
	</bean>

	<bean id="messageSource"
		class="org.springframework.context.support.ResourceBundleMessageSource">
		<property name="basename" value="props"></property>
	</bean>
</beans>

Lets run our application

Now lets run our application, do a clean build and deploy the application in the Server

Hit on the url “http://localhost:8080/SpringMVCFormHandling/RadioButtonExample”

Submit the form without selecting any coiu

Upon successful validation, success page will be rendered to the user