@NotNull(message="Field Required!") @NumberFormat(style = Style.NUMBER) @Min(1)
private Long employeeId;

• We will create a employee enrollment page which will capture the required fields.
• We will add validation logic to the form using Spring MVC validation annotations using hibernate-validator which is an implementation of JSR 303.
• A successful page if validation is successful.

1. Update POM file to get dependencies for Spring Web MVC.
2. Add declaration for Spring DispatcherServler servlet in web.xml.
3. Create Web Application Context file + Define Error property file as message resource in the Context file.
4. Create Model + Add constraint/validation.
5. Create Controller.
6. Create JSP Page.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        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">

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

	<bean id="viewResolver"	class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="cache" value="true" />
		<property name="prefix" value="/WEB-INF/jspPages/" />
		<property name="suffix" value=".jsp" />
		<property name="redirectHttp10Compatible" value="false" />
	</bean>
	
	 <bean id="messageSource"
          class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
                <property name="basenames">
                 <list>
                   <value>classpath:/com/visionjava/employee/error</value>
                 </list>
               </property>
               <property name="cacheSeconds" value="3600"/>
         </bean>	

</beans>

<context:component-scan base-package="com.visionjava" /> scans the defined packages and registers the beans with application context(like controller, bean).

<mvc:annotation-driven /> declares explicit support for new Spring MVC features like @Valid, @RequestBody, @RequestResponse etc.

<bean id="viewResolver"	class="org.springframework.web.servlet.view.InternalResourceViewResolver"> provides access to controller for the jsp pages under WEB-INF folder. It's a good practice to put all the jsp pages under WEB-INF folder to avoid giving direct access.

Lets spend time examining the messageSource id we declared.

We use Spring's ReloadableResourceBundleMessageSource to load our message resource files. Using propert "basenames" we provide the list of all our message resource files. ReloadableResourceBundleMessageSource gives us the feasibility to define time in milliseconds when the file is polled and any changes are loaded without redeploying the application.

error.properties 

typeMismatch.employee.dateOfBirth=Entered Date is not a vlaid format!
Pattern.employee.placeofBirth=Field accepts characters only!

EmployeeController.java

package com.visionjava.employee.controller;

import javax.validation.Valid;

import org.springframework.beans.propertyeditors.StringTrimmerEditor;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.visionjava.employee.model.Employee;

@Controller
public class EmployeeController {
	
	@InitBinder
	public void allowEmptyDateBinding( WebDataBinder binder )
	{
	    // tell spring to set empty values as null instead of empty string.
	    binder.registerCustomEditor( String.class, new StringTrimmerEditor( true ));
	   
	}

	@RequestMapping("/")
	public String showHomePage(){		
		return "employeeHomePage";
	}
	
	@RequestMapping(value="/enroll", method = RequestMethod.GET)
	public ModelAndView showEnrollmentPage(){		
		ModelAndView modelAndView = new ModelAndView("employeeEnrollment");
		modelAndView.addObject("employee", new Employee());
		return modelAndView;
	}
	
	@RequestMapping(value="/submitEnrollment", method = RequestMethod.POST)
	public String submitEnrollment(@Valid @ModelAttribute("employee") Employee employee, 

									BindingResult bindingResult, ModelMap modelMap ){		
		
		if(bindingResult.hasErrors()){
			return "employeeEnrollment";
		}
		
		return "employeeHomePage";
	}
	
}

@Controller -- declares the class as Spring Controller type class.

@RequestMapping("/")-- Annotation for mapping web requests onto specific handler classes and/or handler methods.In our case the homepage request is handled by this controller.

The return value is resolved by the view resolver which appends the location and suffix for the string.

employeeHomePage.jsp

										<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<!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>Employee Enrollment Form</title>
</head>
<body>
	
		<h1>Employee Enrollment Form</h1>
	
<form:form name="employee" id="enrollmentForm" action="submitEnrollment" commandName="employee">
	<table cellspacing="0" cellpadding="0" border="0" width="718">
		<tr>
			<td>Employee ID:</td>
			<td><form:input path="employeeId" /> <form:errors path="employeeId" cssStyle="color:red"/></td>
		</tr>
		<tr>
			<td colspan="2">&nbsp;</td>
		</tr>
		<tr>
			<td>Employee First Name:</td>
			<td><form:input path="firstName" /> <form:errors
					path="firstName" cssStyle="color:red"/></td>
		</tr>
		<tr>
			<td colspan="2">&nbsp;</td>
		</tr>
		<tr>
			<td>Employee Last Name:</td>
			<td><form:input path="lastName" /> <form:errors path="lastName" cssStyle="color:red"/></td>
		</tr>
		<tr>
			<td colspan="2">&nbsp;</td>
		</tr>
		<tr>
			<td>Employee Date Of Birth:</td>
			<td><form:input path="dateOfBirth" /> <form:errors
					path="dateOfBirth" cssStyle="color:red"/></td>
		</tr>
		<tr>
			<td colspan="2">&nbsp;</td>
		</tr>
		<tr>
			<td>Place Of Birth:</td>
			<td><form:input path="placeofBirth" /> <form:errors
					path="placeofBirth" cssStyle="color:red"/></td>
		</tr>
		<tr>
			<td colspan="2">&nbsp;</td>
		</tr>
		<tr>
		<td colspan="2" align="center">
		<input type="submit" id="submitButton" name="enrollmentSubmit" value="Submit Enrollment"/>
	</table>
</form:form>



</body>
</html>