spring-mvc-form-handling-demo

In this tutorial, we will show you a Spring MVC form handling project to do the following stuff :

  1. Form value binding – JSP and Model.
  2. Form validation and display error message.
  3. Form POST/REDIRECT/GET pattern, and add messages to flash attribute.
  4. CRUD operations, add, get, update and delete with an HTML form.

Technologies used :

  1. Spring 4.1.6.RELEASE
  2. Maven 3
  3. Bootstrap 3
  4. HSQLDB driver 2.3.2
  5. Logback 1.1.3
  6. JDK 1.7
  7. JSTL 1.2
  8. Eclipse IDE

What you’ll build :
A simple user management project, you can list, create, update and delete an user, via HTML forms. You’ll also see how to perform the form validation and display the error message conditionally. This project is styling with Bootstrap 3, and data are stored in the HSQL embedded database.

The URI structure :

URIMethodAction
/usersGETListing, display all users
/usersPOSTSave or update user
/users/{id}GETDisplay user {id}
/users/addGETDisplay add user form
/users/{id}/updateGETDisplay update user form for {id}
/users/{id}/deletePOSTDelete user {id}
Note
In the old days, before Spring 3.0, we use SimpleFormController to do the form handling. As Spring 3.0, this class is deprecated in favor of Spring annotated @Controller.

Spring MVC Form Binding

Before you start the tutorial, you need to understand how the Spring MVC form binding works.

1.1 In controller, you add an object into a model attribute.


	@RequestMapping(value = "/users/add", method = RequestMethod.GET)
	public String showAddUserForm(Model model) {

		User user = new User();
		model.addAttribute("userForm", user);
		//...
	}

1.2 In HTML form, you use spring:form tag and bind the controller object via modelAttribute.


<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>

	<form:form method="post" modelAttribute="userForm" action="${userActionUrl}">
		<form:input path="name" type="text" /> <!-- bind to user.name-->
		<form:errors path="name" />
	</form:form>

1.3 When the HTML form is “POST”, you get the value via @ModelAttribute.


@RequestMapping(value = "/users", method = RequestMethod.POST)
public String saveOrUpdateUser(@ModelAttribute("userForm") User user,
		BindingResult result, Model model) {
	//...
}

Done. Let start the tutorial.

1. Project Directory

This is the final project directory structure. A standard Maven project.

spring-mvc-form-handling-directory

2. Project Dependencies

To develop a Spring MVC project, you need spring-webmvc.

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
	http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.mkyong.form</groupId>
	<artifactId>spring-mvc-form</artifactId>
	<packaging>war</packaging>
	<version>1.0-SNAPSHOT</version>
	<name>SpringMVC + Form Handling Example</name>

	<properties>
		<jdk.version>1.7</jdk.version>
		<spring.version>4.1.6.RELEASE</spring.version>
		<hsqldb.version>2.3.2</hsqldb.version>
		<logback.version>1.1.3</logback.version>
		<jcl.slf4j.version>1.7.12</jcl.slf4j.version>
		<jstl.version>1.2</jstl.version>
		<servletapi.version>3.1.0</servletapi.version>
	</properties>

	<dependencies>

		<!-- Spring Core -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</artifactId>
			<version>${spring.version}</version>
			<exclusions>
			   <exclusion>
				<groupId>commons-logging</groupId>
				<artifactId>commons-logging</artifactId>
			    </exclusion>
			</exclusions>
		</dependency>

		<!-- Spring Web -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<!-- Spring JDBC -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-jdbc</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<!-- HyperSQL DB -->
		<dependency>
			<groupId>org.hsqldb</groupId>
			<artifactId>hsqldb</artifactId>
			<version>${hsqldb.version}</version>
		</dependency>

		<!-- logging -->
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>jcl-over-slf4j</artifactId>
			<version>${jcl.slf4j.version}</version>
		</dependency>

		<dependency>
			<groupId>ch.qos.logback</groupId>
			<artifactId>logback-classic</artifactId>
			<version>${logback.version}</version>
		</dependency>

		<!-- jstl -->
		<dependency>
			<groupId>jstl</groupId>
			<artifactId>jstl</artifactId>
			<version>${jstl.version}</version>
		</dependency>

		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<version>${servletapi.version}</version>
			<scope>provided</scope>
		</dependency>

	</dependencies>

	<build>
		<plugins>
		
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>3.3</version>
				<configuration>
					<source>${jdk.version}</source>
					<target>${jdk.version}</target>
				</configuration>
			</plugin>

			<!-- embedded Jetty server, for testing -->
			<plugin>
				<groupId>org.eclipse.jetty</groupId>
				<artifactId>jetty-maven-plugin</artifactId>
				<version>9.2.11.v20150529</version>
				<configuration>
				  <scanIntervalSeconds>10</scanIntervalSeconds>
				  <webApp>
					<contextPath>/spring-mvc-form</contextPath>
				  </webApp>
				</configuration>
			</plugin>

			<!-- configure Eclipse workspace -->
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-eclipse-plugin</artifactId>
				<version>2.9</version>
				<configuration>
					<downloadSources>true</downloadSources>
					<downloadJavadocs>true</downloadJavadocs>
					<wtpversion>2.0</wtpversion>
					<wtpContextName>spring-mvc-form</wtpContextName>
				</configuration>
			</plugin>

		</plugins>
	</build>
</project>

3. Controller

Spring @Controller class to show you how to bind the form value via @ModelAttribute, add a form validator, add message into flash attribute, populate values for dropdown and checkboxes and etc. Read the comments for self-explanatory.

UserController.java

package com.mkyong.form.web;

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

import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import com.mkyong.form.model.User;
import com.mkyong.form.service.UserService;
import com.mkyong.form.validator.UserFormValidator;

@Controller
public class UserController {

	private final Logger logger = LoggerFactory.getLogger(UserController.class);

	@Autowired
	private UserService userService;

	@Autowired
	UserFormValidator userFormValidator;
	
	//Set a form validator
	@InitBinder
	protected void initBinder(WebDataBinder binder) {
		binder.setValidator(userFormValidator);
	}
	
	@RequestMapping(value = "/", method = RequestMethod.GET)
	public String index(Model model) {
		logger.debug("index()");
		return "redirect:/users";
	}

	// list page
	@RequestMapping(value = "/users", method = RequestMethod.GET)
	public String showAllUsers(Model model) {

		logger.debug("showAllUsers()");
		model.addAttribute("users", userService.findAll());
		return "users/list";

	}

	// save or update user
	// 1. @ModelAttribute bind form value
	// 2. @Validated form validator
	// 3. RedirectAttributes for flash value
	@RequestMapping(value = "/users", method = RequestMethod.POST)
	public String saveOrUpdateUser(@ModelAttribute("userForm") @Validated User user,
			BindingResult result, Model model, 
			final RedirectAttributes redirectAttributes) {

		logger.debug("saveOrUpdateUser() : {}", user);

		if (result.hasErrors()) {
			populateDefaultModel(model);
			return "users/userform";
		} else {

			// Add message to flash scope
			redirectAttributes.addFlashAttribute("css", "success");
			if(user.isNew()){
			  redirectAttributes.addFlashAttribute("msg", "User added successfully!");
			}else{
			  redirectAttributes.addFlashAttribute("msg", "User updated successfully!");
			}
			
			userService.saveOrUpdate(user);
			
			// POST/REDIRECT/GET
			return "redirect:/users/" + user.getId();

			// POST/FORWARD/GET
			// return "user/list";

		}

	}

	// show add user form
	@RequestMapping(value = "/users/add", method = RequestMethod.GET)
	public String showAddUserForm(Model model) {

		logger.debug("showAddUserForm()");

		User user = new User();

		// set default value
		user.setName("mkyong123");
		user.setEmail("test@gmail.com");
		user.setAddress("abc 88");
		user.setNewsletter(true);
		user.setSex("M");
		user.setFramework(new ArrayList<String>(Arrays.asList("Spring MVC", "GWT")));
		user.setSkill(new ArrayList<String>(Arrays.asList("Spring", "Grails", "Groovy")));
		user.setCountry("SG");
		user.setNumber(2);
		model.addAttribute("userForm", user);

		populateDefaultModel(model);

		return "users/userform";

	}

	// show update form
	@RequestMapping(value = "/users/{id}/update", method = RequestMethod.GET)
	public String showUpdateUserForm(@PathVariable("id") int id, Model model) {

		logger.debug("showUpdateUserForm() : {}", id);

		User user = userService.findById(id);
		model.addAttribute("userForm", user);
		
		populateDefaultModel(model);
		
		return "users/userform";

	}

	// delete user
	@RequestMapping(value = "/users/{id}/delete", method = RequestMethod.POST)
	public String deleteUser(@PathVariable("id") int id, 
		final RedirectAttributes redirectAttributes) {

		logger.debug("deleteUser() : {}", id);

		userService.delete(id);
		
		redirectAttributes.addFlashAttribute("css", "success");
		redirectAttributes.addFlashAttribute("msg", "User is deleted!");
		
		return "redirect:/users";

	}

	// show user
	@RequestMapping(value = "/users/{id}", method = RequestMethod.GET)
	public String showUser(@PathVariable("id") int id, Model model) {

		logger.debug("showUser() id: {}", id);

		User user = userService.findById(id);
		if (user == null) {
			model.addAttribute("css", "danger");
			model.addAttribute("msg", "User not found");
		}
		model.addAttribute("user", user);

		return "users/show";

	}

	private void populateDefaultModel(Model model) {

		List<String> frameworksList = new ArrayList<String>();
		frameworksList.add("Spring MVC");
		frameworksList.add("Struts 2");
		frameworksList.add("JSF 2");
		frameworksList.add("GWT");
		frameworksList.add("Play");
		frameworksList.add("Apache Wicket");
		model.addAttribute("frameworkList", frameworksList);

		Map<String, String> skill = new LinkedHashMap<String, String>();
		skill.put("Hibernate", "Hibernate");
		skill.put("Spring", "Spring");
		skill.put("Struts", "Struts");
		skill.put("Groovy", "Groovy");
		skill.put("Grails", "Grails");
		model.addAttribute("javaSkillList", skill);

		List<Integer> numbers = new ArrayList<Integer>();
		numbers.add(1);
		numbers.add(2);
		numbers.add(3);
		numbers.add(4);
		numbers.add(5);
		model.addAttribute("numberList", numbers);

		Map<String, String> country = new LinkedHashMap<String, String>();
		country.put("US", "United Stated");
		country.put("CN", "China");
		country.put("SG", "Singapore");
		country.put("MY", "Malaysia");
		model.addAttribute("countryList", country);

	}

}

4. Form Validator

4.1 Spring validator example.

UserFormValidator.java

package com.mkyong.form.validator;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

import com.mkyong.form.model.User;
import com.mkyong.form.service.UserService;

@Component
public class UserFormValidator implements Validator {

	@Autowired
	@Qualifier("emailValidator")
	EmailValidator emailValidator;
	
	@Autowired
	UserService userService;
	
	@Override
	public boolean supports(Class<?> clazz) {
		return User.class.equals(clazz);
	}

	@Override
	public void validate(Object target, Errors errors) {

		User user = (User) target;

		ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "NotEmpty.userForm.name");
		ValidationUtils.rejectIfEmptyOrWhitespace(errors, "email", "NotEmpty.userForm.email");
		ValidationUtils.rejectIfEmptyOrWhitespace(errors, "address", "NotEmpty.userForm.address");
		ValidationUtils.rejectIfEmptyOrWhitespace(errors, "password", "NotEmpty.userForm.password");
		ValidationUtils.rejectIfEmptyOrWhitespace(errors, "confirmPassword","NotEmpty.userForm.confirmPassword");
		ValidationUtils.rejectIfEmptyOrWhitespace(errors, "sex", "NotEmpty.userForm.sex");
		ValidationUtils.rejectIfEmptyOrWhitespace(errors, "country", "NotEmpty.userForm.country");

		if(!emailValidator.valid(user.getEmail())){
			errors.rejectValue("email", "Pattern.userForm.email");
		}
		
		if(user.getNumber()==null || user.getNumber()<=0){
			errors.rejectValue("number", "NotEmpty.userForm.number");
		}
		
		if(user.getCountry().equalsIgnoreCase("none")){
			errors.rejectValue("country", "NotEmpty.userForm.country");
		}
		
		if (!user.getPassword().equals(user.getConfirmPassword())) {
			errors.rejectValue("confirmPassword", "Diff.userform.confirmPassword");
		}
		
		if (user.getFramework() == null || user.getFramework().size() < 2) {
			errors.rejectValue("framework", "Valid.userForm.framework");
		}

		if (user.getSkill() == null || user.getSkill().size() < 3) {
			errors.rejectValue("skill", "Valid.userForm.skill");
		}

	}

}
validation.properties

NotEmpty.userForm.name = Name is required!
NotEmpty.userForm.email = Email is required!
NotEmpty.userForm.address = Address is required!
NotEmpty.userForm.password = Password is required!
NotEmpty.userForm.confirmPassword = Confirm password is required!
NotEmpty.userForm.sex = Sex is required!
NotEmpty.userForm.number = Number is required!
NotEmpty.userForm.country = Country is required!
Valid.userForm.framework = Please select at least two frameworks!
Valid.userForm.skill = Please select at least three skills!
Diff.userform.confirmPassword = Passwords do not match, please retype!
Pattern.userForm.email = Invalid Email format!	

To run the Spring Validator, add the validator via @InitBinder and annotate the model with @Validated


@InitBinder
protected void initBinder(WebDataBinder binder) {
	binder.setValidator(userFormValidator);
}

@RequestMapping(value = "/users", method = RequestMethod.POST)
public String saveOrUpdateUser(... @Validated User user,
		...) {

	//...

}

Or run it manually.


@RequestMapping(value = "/users", method = RequestMethod.POST)
public String saveOrUpdateUser(... User user,
		...) {
	userFormValidator.validate(user, result);	
	//...
}

5. HTML Forms

All the HTML forms are css styling with Bootstrap framework, and using Spring form tags to do the display and form binding.
5.1 User Listings.

list.jsp

<%@ page session="false"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>

<!DOCTYPE html>
<html lang="en">

<jsp:include page="../fragments/header.jsp" />

<body>

	<div class="container">

		<c:if test="${not empty msg}">
		    <div class="alert alert-${css} alert-dismissible" role="alert">
			<button type="button" class="close" data-dismiss="alert" 
                                aria-label="Close">
				<span aria-hidden="true">×</span>
			</button>
			<strong>${msg}</strong>
		    </div>
		</c:if>

		<h1>All Users</h1>

		<table class="table table-striped">
			<thead>
				<tr>
					<th>#ID</th>
					<th>Name</th>
					<th>Email</th>
					<th>framework</th>
					<th>Action</th>
				</tr>
			</thead>

			<c:forEach var="user" items="${users}">
			    <tr>
				<td>
					${user.id}
				</td>
				<td>${user.name}</td>
				<td>${user.email}</td>
				<td>
                                  <c:forEach var="framework" items="${user.framework}" 
                                                             varStatus="loop">
					${framework}
    				        <c:if test="${not loop.last}">,</c:if>
				  </c:forEach>
                                </td>
				<td>
				  <spring:url value="/users/${user.id}" var="userUrl" />
				  <spring:url value="/users/${user.id}/delete" var="deleteUrl" /> 
				  <spring:url value="/users/${user.id}/update" var="updateUrl" />

				  <button class="btn btn-info" 
                                          onclick="location.href='${userUrl}'">Query</button>
				  <button class="btn btn-primary" 
                                          onclick="location.href='${updateUrl}'">Update</button>
				  <button class="btn btn-danger" 
                                          onclick="this.disabled=true;post('${deleteUrl}')">Delete</button>
                                </td>
			    </tr>
			</c:forEach>
		</table>

	</div>

	<jsp:include page="../fragments/footer.jsp" />

</body>
</html>
show.jsp

<%@ page session="false"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>

<!DOCTYPE html>
<html lang="en">

<jsp:include page="../fragments/header.jsp" />

<div class="container">

	<c:if test="${not empty msg}">
		<div class="alert alert-${css} alert-dismissible" role="alert">
			<button type="button" class="close" data-dismiss="alert" 
                                aria-label="Close">
				<span aria-hidden="true">×</span>
			</button>
			<strong>${msg}</strong>
		</div>
	</c:if>

	<h1>User Detail</h1>
	<br />

	<div class="row">
		<label class="col-sm-2">ID</label>
		<div class="col-sm-10">${user.id}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Name</label>
		<div class="col-sm-10">${user.name}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Email</label>
		<div class="col-sm-10">${user.email}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Address</label>
		<div class="col-sm-10">${user.address}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Newsletter</label>
		<div class="col-sm-10">${user.newsletter}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Web Frameworks</label>
		<div class="col-sm-10">${user.framework}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Sex</label>
		<div class="col-sm-10">${user.sex}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Number</label>
		<div class="col-sm-10">${user.number}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Country</label>
		<div class="col-sm-10">${user.country}</div>
	</div>

	<div class="row">
		<label class="col-sm-2">Skill</label>
		<div class="col-sm-10">${user.skill}</div>
	</div>

</div>

<jsp:include page="../fragments/footer.jsp" />

</body>
</html>
userform.jsp

<%@ page session="false"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>

<!DOCTYPE html>
<html lang="en">

<jsp:include page="../fragments/header.jsp" />

<div class="container">

	<c:choose>
		<c:when test="${userForm['new']}">
			<h1>Add User</h1>
		</c:when>
		<c:otherwise>
			<h1>Update User</h1>
		</c:otherwise>
	</c:choose>
	<br />

	<spring:url value="/users" var="userActionUrl" />

	<form:form class="form-horizontal" method="post" 
                modelAttribute="userForm" action="${userActionUrl}">

		<form:hidden path="id" />

		<spring:bind path="name">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Name</label>
			<div class="col-sm-10">
				<form:input path="name" type="text" class="form-control" 
                                id="name" placeholder="Name" />
				<form:errors path="name" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="email">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Email</label>
			<div class="col-sm-10">
				<form:input path="email" class="form-control" 
                                id="email" placeholder="Email" />
				<form:errors path="email" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="password">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Password</label>
			<div class="col-sm-10">
				<form:password path="password" class="form-control" 
                                id="password" placeholder="password" />
				<form:errors path="password" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="confirmPassword">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">confirm Password</label>
			<div class="col-sm-10">
				<form:password path="confirmPassword" class="form-control" 
                                id="password" placeholder="password" />
				<form:errors path="confirmPassword" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="address">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Address</label>
			<div class="col-sm-10">
				<form:textarea path="address" rows="5" class="form-control" 
                                id="address" placeholder="address" />
				<form:errors path="address" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="newsletter">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Newsletter</label>
			<div class="col-sm-10">
				<div class="checkbox">
				  <label> 
                                     <form:checkbox path="newsletter" id="newsletter" />
				  </label>
				     <form:errors path="newsletter" class="control-label" />
				</div>
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="framework">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Web Frameworks</label>
			<div class="col-sm-10">
				<form:checkboxes path="framework" items="${frameworkList}" 
                                 element="label class='checkbox-inline'" />
				<br />
				<form:errors path="framework" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="sex">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Sex</label>
			<div class="col-sm-10">
				<label class="radio-inline"> 
                                  <form:radiobutton path="sex" value="M" /> Male
				</label> 
                                <label class="radio-inline"> 
                                  <form:radiobutton path="sex" value="F" /> Female
				</label> <br />
				<form:errors path="sex" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="number">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Number</label>
			<div class="col-sm-10">
				<form:radiobuttons path="number" items="${numberList}" 
                                element="label class='radio-inline'" />
				<br />
				<form:errors path="number" class="control-label" />
			</div>
		  </div>
		</spring:bind>

		<spring:bind path="country">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Country</label>
			<div class="col-sm-5">
				<form:select path="country" class="form-control">
					<form:option value="NONE" label="--- Select ---" />
					<form:options items="${countryList}" />
				</form:select>
				<form:errors path="country" class="control-label" />
			</div>
			<div class="col-sm-5"></div>
		  </div>
		</spring:bind>

		<spring:bind path="skill">
		  <div class="form-group ${status.error ? 'has-error' : ''}">
			<label class="col-sm-2 control-label">Java Skills</label>
			<div class="col-sm-5">
				<form:select path="skill" items="${javaSkillList}" 
                                 multiple="true" size="5" class="form-control" />
				<form:errors path="skill" class="control-label" />
			</div>
			<div class="col-sm-5"></div>
		  </div>
		</spring:bind>

		<div class="form-group">
		  <div class="col-sm-offset-2 col-sm-10">
			<c:choose>
			  <c:when test="${userForm['new']}">
			     <button type="submit" class="btn-lg btn-primary pull-right">Add
                             </button>
			  </c:when>
			  <c:otherwise>
			     <button type="submit" class="btn-lg btn-primary pull-right">Update
                             </button>
			  </c:otherwise>
			</c:choose>
		  </div>
		</div>
	</form:form>

</div>

<jsp:include page="../fragments/footer.jsp" />

</body>
</html>

6. Database Stuff

6.1 Create a table and insert some data for testing.

create-db.sql

CREATE TABLE users (
  id INTEGER GENERATED BY DEFAULT AS IDENTITY(START WITH 100, INCREMENT BY 1) PRIMARY KEY,
  name VARCHAR(30),
  email  VARCHAR(50),
  address VARCHAR(255),
  password VARCHAR(20),
  newsletter BOOLEAN,
  framework VARCHAR(500),
  sex VARCHAR(1),
  NUMBER INTEGER,
  COUNTRY VARCHAR(10),
  SKILL VARCHAR(500)
);
insert-data.sql

INSERT INTO users (name, email, framework) VALUES ('mkyong', 'mkyong@gmail.com', 'Spring MVC, GWT');
INSERT INTO users (name, email) VALUES ('alex', 'alex@yahoo.com', 'Spring MVC, GWT');
INSERT INTO users (name, email) VALUES ('joel', 'joel@gmail.com', 'Spring MVC, GWT');

6.2 Start a HSQLDB embedded database, create a datasource and jdbcTemplate.

SpringDBConfig.java

package com.mkyong.form.config;

import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabase;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;

@Configuration
public class SpringDBConfig {

	@Autowired
	DataSource dataSource;

	@Bean
	public NamedParameterJdbcTemplate getNamedParameterJdbcTemplate() {
		return new NamedParameterJdbcTemplate(dataSource);
	}

	@Bean
	public DataSource getDataSource() {
		EmbeddedDatabaseBuilder builder = new EmbeddedDatabaseBuilder();
		EmbeddedDatabase db = builder.setName("testdb")
                        .setType(EmbeddedDatabaseType.HSQL)
			.addScript("db/sql/create-db.sql")
                        .addScript("db/sql/insert-data.sql").build();
		return db;
	}

}

6.3 User object.

user.java

package com.mkyong.form.model;

import java.util.List;

public class User {
	// form:hidden - hidden value
	Integer id;

	// form:input - textbox
	String name;

	// form:input - textbox
	String email;

	// form:textarea - textarea
	String address;

	// form:input - password
	String password;

	// form:input - password
	String confirmPassword;

	// form:checkbox - single checkbox
	boolean newsletter;

	// form:checkboxes - multiple checkboxes
	List<String> framework;

	// form:radiobutton - radio button
	String sex;

	// form:radiobuttons - radio button
	Integer number;

	// form:select - form:option - dropdown - single select
	String country;

	// form:select - multiple=true - dropdown - multiple select
	List<String> skill;

	//Check if this is for New of Update
	public boolean isNew() {
		return (this.id == null);
	}

	//...

}

7. Services and DAO

UserService.java

package com.mkyong.form.service;

import java.util.List;
import com.mkyong.form.model.User;

public interface UserService {

	User findById(Integer id);
	
	List<User> findAll();

	void saveOrUpdate(User user);
	
	void delete(int id);
	
}
UserServiceImpl.java

package com.mkyong.form.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.mkyong.form.dao.UserDao;
import com.mkyong.form.model.User;

@Service("userService")
public class UserServiceImpl implements UserService {

	UserDao userDao;

	@Autowired
	public void setUserDao(UserDao userDao) {
		this.userDao = userDao;
	}

	@Override
	public User findById(Integer id) {
		return userDao.findById(id);
	}

	@Override
	public List<User> findAll() {
		return userDao.findAll();
	}

	@Override
	public void saveOrUpdate(User user) {

		if (findById(user.getId())==null) {
			userDao.save(user);
		} else {
			userDao.update(user);
		}

	}

	@Override
	public void delete(int id) {
		userDao.delete(id);
	}

}
UserDao.java

package com.mkyong.form.dao;

import java.util.List;

import com.mkyong.form.model.User;

public interface UserDao {

	User findById(Integer id);

	List<User> findAll();

	void save(User user);

	void update(User user);

	void delete(Integer id);

}
UserDaoImpl.java

package com.mkyong.form.dao;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;
import org.springframework.jdbc.support.GeneratedKeyHolder;
import org.springframework.jdbc.support.KeyHolder;
import org.springframework.stereotype.Repository;
import org.springframework.util.StringUtils;

import com.mkyong.form.model.User;

@Repository
public class UserDaoImpl implements UserDao {

	NamedParameterJdbcTemplate namedParameterJdbcTemplate;

	@Autowired
	public void setNamedParameterJdbcTemplate(
		NamedParameterJdbcTemplate namedParameterJdbcTemplate) {
		this.namedParameterJdbcTemplate = namedParameterJdbcTemplate;
	}

	@Override
	public User findById(Integer id) {

		Map<String, Object> params = new HashMap<String, Object>();
		params.put("id", id);

		String sql = "SELECT * FROM users WHERE id=:id";

		User result = null;
		try {
			result = namedParameterJdbcTemplate
                          .queryForObject(sql, params, new UserMapper());
		} catch (EmptyResultDataAccessException e) {
			// do nothing, return null
		}

		return result;

	}

	@Override
	public List<User> findAll() {

		String sql = "SELECT * FROM users";
		List<User> result = namedParameterJdbcTemplate.query(sql, new UserMapper());
		return result;

	}

	@Override
	public void save(User user) {

		KeyHolder keyHolder = new GeneratedKeyHolder();
		
		String sql = "INSERT INTO USERS(NAME, EMAIL, ADDRESS, PASSWORD, NEWSLETTER, FRAMEWORK, SEX, NUMBER, COUNTRY, SKILL) "
				+ "VALUES ( :name, :email, :address, :password, :newsletter, :framework, :sex, :number, :country, :skill)";

		namedParameterJdbcTemplate.update(sql, getSqlParameterByModel(user), keyHolder);
		user.setId(keyHolder.getKey().intValue());
		
	}

	@Override
	public void update(User user) {

		String sql = "UPDATE USERS SET NAME=:name, EMAIL=:email, ADDRESS=:address, " 
			+ "PASSWORD=:password, NEWSLETTER=:newsletter, FRAMEWORK=:framework, "
			+ "SEX=:sex, NUMBER=:number, COUNTRY=:country, SKILL=:skill WHERE id=:id";

		namedParameterJdbcTemplate.update(sql, getSqlParameterByModel(user));

	}

	@Override
	public void delete(Integer id) {

		String sql = "DELETE FROM USERS WHERE id= :id";
		namedParameterJdbcTemplate.update(sql, new MapSqlParameterSource("id", id));

	}

	private SqlParameterSource getSqlParameterByModel(User user) {

		MapSqlParameterSource paramSource = new MapSqlParameterSource();
		paramSource.addValue("id", user.getId());
		paramSource.addValue("name", user.getName());
		paramSource.addValue("email", user.getEmail());
		paramSource.addValue("address", user.getAddress());
		paramSource.addValue("password", user.getPassword());
		paramSource.addValue("newsletter", user.isNewsletter());

		// join String
		paramSource.addValue("framework", convertListToDelimitedString(user.getFramework()));
		paramSource.addValue("sex", user.getSex());
		paramSource.addValue("number", user.getNumber());
		paramSource.addValue("country", user.getCountry());
		paramSource.addValue("skill", convertListToDelimitedString(user.getSkill()));

		return paramSource;
	}

	private static final class UserMapper implements RowMapper<User> {

		public User mapRow(ResultSet rs, int rowNum) throws SQLException {
			User user = new User();
			user.setId(rs.getInt("id"));
			user.setName(rs.getString("name"));
			user.setEmail(rs.getString("email"));
			user.setFramework(convertDelimitedStringToList(rs.getString("framework")));
			user.setAddress(rs.getString("address"));
			user.setCountry(rs.getString("country"));
			user.setNewsletter(rs.getBoolean("newsletter"));
			user.setNumber(rs.getInt("number"));
			user.setPassword(rs.getString("password"));
			user.setSex(rs.getString("sex"));
			user.setSkill(convertDelimitedStringToList(rs.getString("skill")));
			return user;
		}
	}

	private static List<String> convertDelimitedStringToList(String delimitedString) {

		List<String> result = new ArrayList<String>();

		if (!StringUtils.isEmpty(delimitedString)) {
			result = Arrays.asList(StringUtils.delimitedListToStringArray(delimitedString, ","));
		}
		return result;

	}

	private String convertListToDelimitedString(List<String> list) {

		String result = "";
		if (list != null) {
			result = StringUtils.arrayToCommaDelimitedString(list.toArray());
		}
		return result;

	}

}

8. Spring Configuration

Mixing Spring XML and JavaConfig.

SpringWebConfig.java

package com.mkyong.form.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@EnableWebMvc
@Configuration
@ComponentScan({ "com.mkyong.form.web", "com.mkyong.form.service", "com.mkyong.form.dao",
		"com.mkyong.form.exception", "com.mkyong.form.validator" })
public class SpringWebConfig extends WebMvcConfigurerAdapter {

	@Override
	public void addResourceHandlers(ResourceHandlerRegistry registry) {
		registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
	}

	@Bean
	public InternalResourceViewResolver viewResolver() {
		InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
		viewResolver.setViewClass(JstlView.class);
		viewResolver.setPrefix("/WEB-INF/views/jsp/");
		viewResolver.setSuffix(".jsp");
		return viewResolver;
	}

	@Bean
	public ResourceBundleMessageSource messageSource() {
		ResourceBundleMessageSource rb = new ResourceBundleMessageSource();
		rb.setBasenames(new String[] { "messages/messages", "messages/validation" });
		return rb;
	}

}
spring-web-servlet.xml

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

    <!-- Scan the JavaConfig -->
	<context:component-scan base-package="com.mkyong.form.config" />
	
</beans>
web.xml

<web-app xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
	version="3.0">

	<display-name>Spring3 MVC Application</display-name>

	<servlet>
		<servlet-name>spring-web</servlet-name>
		<servlet-class>
			org.springframework.web.servlet.DispatcherServlet
		</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet-mapping>
		<servlet-name>spring-web</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>

	<error-page>
		<error-code>500</error-code>
		<location>/WEB-INF/views/jsp/error.jsp</location>
	</error-page>

	<error-page>
		<error-code>404</error-code>
		<location>/WEB-INF/views/jsp/error.jsp</location>
	</error-page>

	<error-page>
		<location>/WEB-INF/views/jsp/error.jsp</location>
	</error-page>

</web-app>

9. Demo

Download the project and type mvn jetty:run


$ mvn jetty:run
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building SpringMVC + Form Handling Example 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
//...
[INFO] Started Jetty Server
[INFO] Starting scanner at interval of 10 seconds.

9.1 List all users. http://localhost:8080/spring-mvc-form/users

spring-mvc-form-handling-demo1

9.2 Add an user. http://localhost:8080/spring-mvc-form/users/add

spring-mvc-form-handling-demo-add

9.3 Form validation.

spring-mvc-form-handling-demo-add-error

9.4 New user is added. http://localhost:8080/spring-mvc-form/users

spring-mvc-form-handling-demo-add-done

9.5 Delete an user. http://localhost:8080/spring-mvc-form/users/104/delete

spring-mvc-form-handling-demo-delete

Download Source Code

Download it - spring4-form-handle-example.zip (80 kb)
Github - TBD

References

  1. Using Spring’s form tag library
  2. Spring MVC 3 Validation
  3. RedirectAttributes JavaDoc