Rai Studies

              First of all we will see the form validator used in this example. Here is the code:

package com.raistudies.validator;

import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

import com.raistudies.domain.User;

@Component
public class RegistrationValidator implements Validator {

        public boolean supports(Class<?> c) {
                return User.class.isAssignableFrom(c);
        }

        public void validate(Object command, Errors errors) {
                ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "field.name.empty");
                ValidationUtils.rejectIfEmptyOrWhitespace(errors, "standard", "field.standard.empty");
                ValidationUtils.rejectIfEmptyOrWhitespace(errors, "age", "field.age.empty");
                ValidationUtils.rejectIfEmptyOrWhitespace(errors, "sex", "field.sex.empty");
                User usrBean = (User)command;
                if(!isNumber(usrBean.getAge().trim()))
                        errors.rejectValue("age", "field.age.NAN");
        }

        private boolean isNumber(String str){
            for (int i = 0; i < str.length(); i++) {

                //If we find a non-digit character we return false.
                if (!Character.isDigit(str.charAt(i)))
                return false;
                }

                return true;
        }
}

    As you can see, we have put some restrictions on the form values like every field should have values and the value in “age” field should be number. You can add more restrictions on the form values as you need from the validate() method of this class.

    The contain of the error message values are defined in the property file messages.properties, which is as bellow :

field.name.empty=Name field is mandatory.
field.standard.empty=Standard field is mandatory.
field.age.empty=Age field is mandatory.
field.sex.empty=Sex field is mandatory.

field.age.NAN=Age should be a number.

That is all for the form validation part, now we will see controller part.

package com.raistudies.controllers;

import java.util.List;
import java.util.UUID;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
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.raistudies.domain.User;
import com.raistudies.persistence.UserService;
import com.raistudies.validator.RegistrationValidator;

@Controller
@RequestMapping(value="/registration")
public class RegistrationController {

        private RegistrationValidator validator = null;
        private UserService userService = null;

        @Autowired
        public void setUserService(UserService userService) {
                this.userService = userService;
        }

        public RegistrationValidator getValidator() {
                return validator;
        }

        @Autowired
        public void setValidator(RegistrationValidator validator) {
                this.validator = validator;
        }

        @RequestMapping(method=RequestMethod.GET)
        public String showForm(ModelMap model){
                List<User> users = userService.getAllUser();
                model.addAttribute("users", users);
                User user = new User();
                user.setId(UUID.randomUUID().toString());
                model.addAttribute("user", user);
                return "registration";
        }

        @RequestMapping(value="/add", method=RequestMethod.POST)
        public ModelAndView add(@ModelAttribute(value="user") User user,BindingResult result){
                validator.validate(user, result);
                ModelAndView mv = new ModelAndView("registration");
                if(!result.hasErrors()){
                        userService.saveUser(user);
                        user = new User();
                        user.setId(UUID.randomUUID().toString());
                        mv.addObject("user", user);
                }
                mv.addObject("users", userService.getAllUser());
                return mv;
        }

        @RequestMapping(value="/update", method=RequestMethod.POST)
        public ModelAndView update(@ModelAttribute(value="user") User user,BindingResult result){
                validator.validate(user, result);
                ModelAndView mv = new ModelAndView("registration");
                if(!result.hasErrors()){
                        userService.updateUser(user);
                        user = new User();
                        user.setId(UUID.randomUUID().toString());
                        mv.addObject("user", user);
                }
                mv.addObject("users", userService.getAllUser());
                return mv;
        }

        @RequestMapping(value="/delete", method=RequestMethod.POST)
        public ModelAndView delete(@ModelAttribute(value="user") User user,BindingResult result){
                validator.validate(user, result);
                ModelAndView mv = new ModelAndView("registration");
                if(!result.hasErrors()){
                        userService.deleteUser(user.getId());
                        user = new User();
                        user.setId(UUID.randomUUID().toString());
                        mv.addObject("user", user);
                }
                mv.addObject("users", userService.getAllUser());
                return mv;
        }
}

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<pre><!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<%@ page session="true" %>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<html xmlns="http://www.w3.org/1999/xhtml">
        <head>
                <title>Hello World with Spring 3 MVC</title>
                <meta http-equiv="Content-Type" content="text/html; charset=windows-1251">
                <script type="text/javascript" src='<c:url value="/resources/common.js"/>'></script>
                <script type="text/javascript" src='<c:url value="/resources/registration.js"/>'></script>
                <script type="text/javascript">
                        var projectUrl = '<c:url value="/"/>';
                        if(projectUrl.indexOf(";", 0) != -1){
                                projectUrl = projectUrl.substring(0, projectUrl.indexOf(";", 0));
                        }
                </script>
        </head>
        <body>
                <fieldset>
                <legend>Registration Form</legend>
                <center>
                <form:form commandName="user" action="/SpringMVCMyBatisCRUDExample/app/registration/add" name="userForm">

                <form:hidden path="id"/>
                <table>
                        <tr><td colspan="2" align="left"><form:errors path="*" cssStyle="color : red;"/></td></tr>
                        <tr><td>Name : </td><td><form:input path="name" /></td></tr>
                        <tr><td>Standard : </td><td><form:input path="standard" /></td></tr>
                        <tr><td>Age : </td><td><form:input path="age" /></td></tr>
                        <tr><td>Sex : </td><td><form:select path="sex">
                                        <form:option value="Male"/>
                                        <form:option value="Female"/>
                        </form:select></td></tr>
                        <tr><td colspan="2"><input type="submit" value="Save Changes"/>
                        &nbsp;<input type="reset" name="newUser" value="New User" onclick="setAddForm();" disabled="disabled"/>
                        &nbsp;<input type="submit" name="deleteUser" value="Delete User" onclick="setDeleteForm();" disabled="disabled"/></td></tr>
                </table>
                </form:form>
                </center>
                </fieldset>
                <c:if test="${!empty users}">

                        <br />
                        <center>
                                <table width="90%">
                                        <tr style="background-color: gray;">
                                                <th>Name</th>
                                                <th>Standard</th>
                                                <th>Age</th>
                                                <th>Sex</th>
                                        </tr>
                                        <c:forEach items="${users}" var="user">
                                                <tr style="background-color: silver;" id="${user.id}" onclick="setUpdateForm('${user.id}');">
                                                        <td><c:out value="${user.name}"/></td>
                                                        <td><c:out value="${user.standard}"/></td>
                                                        <td><c:out value="${user.age}"/></td>
                                                        <td><c:out value="${user.sex}"/></td>
                                                </tr>
                                        </c:forEach>
                                </table>
                                </center>
                        <br />

                </c:if>
        </body>
</html></pre>
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As you can see, the default action of the form is to add the form detail to database using add method of the controller. On click of “Delete User”, it will call a JavaScript function that will change the form url to delete the user. We have used <c:forEach/> jstl for showing all the users on the table and every  row has declared on click even which will bring the table row data to form and also will change the form submit url to call update() method of controller.

At last we will see the Spring MVC configuration that has been using to configure the controller and all other things. Following is the configuration file :

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<pre><?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:context="http://www.springframework.org/schema/context"
        xmlns:mvc="http://www.springframework.org/schema/mvc"
        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">

        <!-- Application Message Bundle -->
        <bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
                <property name="basename" value="/WEB-INF/messages" />
                <property name="cacheSeconds" value="3000" />
        </bean>

        <!-- Scans the classpath of this application for @Components to deploy as beans -->
        <context:component-scan base-package="com.raistudies" />

        <!-- Configures the @Controller programming model -->
        <mvc:annotation-driven />

        <!-- Resolves view names to protected .jsp resources within the /WEB-INF/views directory -->
        <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
                <property name="prefix" value="/WEB-INF/jsp/"/>
                <property name="suffix" value=".jsp"/>
        </bean>

        <import resource="jdbc-context.xml"/>
</beans></pre>
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