Spring MVC textbox example

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In Spring MVC, you can use <form:input /> tag to render a HTML textbox field. For example,

<form:input path="userName" />

It will renders following HTML code

<input id="userName" name="userName" type="text" value=""/>

In this tutorial, we show you how to use Spring’s form tag “input” to render a HTML textbox to store the “userName“. Additionally, add an empty check validator to make sure the textbox value is not empty.

1. `Controller`

A SimpleFormController to handle the form value, and link the form value to the Customer object.

File : `TextBoxController.java

package com.mkyong.customer.controller;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.validation.BindException;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.mvc.SimpleFormController;import com.mkyong.customer.model.Customer;public class TextBoxController extends SimpleFormController{    public TextBoxController(){        setCommandClass(Customer.class);        setCommandName("customerForm");    }    @Override    protected ModelAndView onSubmit(HttpServletRequest request,        HttpServletResponse response, Object command, BindException errors)        throws Exception {        Customer customer = (Customer)command;        return new ModelAndView("CustomerSuccess","customer",customer);    }}

2. Model

A Customer object to store the text box value.

File : `Customer.java`

package com.mkyong.customer.model;public class Customer{    String userName;    //getter and setter methods}

3. Form Validator

Create a form validator class and use the ValidationUtils class to make sure the “userName” is not empty, Otherwise, get the “required.userName” message from the corresponds resource bundle (properties file).

File : `CustomerValidator.java`

package com.mkyong.customer.validator;import org.springframework.validation.Errors;import org.springframework.validation.ValidationUtils;import org.springframework.validation.Validator;import com.mkyong.customer.model.Customer;public class CustomerValidator implements Validator{    @Override    public boolean supports(Class clazz) {        //just validate the Customer instances        return Customer.class.isAssignableFrom(clazz);    }    @Override    public void validate(Object target, Errors errors) {        ValidationUtils.rejectIfEmptyOrWhitespace(errors, "userName",            "required.userName", "Field name is required.");    }}

File : `message.properties`

required.userName = username is required!

4. View

A JSP page to use the Spring’s form tag “input” to render a HTML textbox, and put some CSS styles to highlight the error message.

File : `CustomerForm.jsp`

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%><html><head><style>.error {    color: #ff0000;}.errorblock {    color: #000;    background-color: #ffEEEE;    border: 3px solid #ff0000;    padding: 8px;    margin: 16px;}</style></head><body>    <h2>Spring's form textbox example</h2>    <form:form method="POST" commandName="customerForm">        <form:errors path="*" cssClass="errorblock" element="div" />        <table>            <tr>                <td>Username :</td>                <td><form:input path="userName" />                </td>                <td><form:errors path="userName" cssClass="error" />                </td>            </tr>            <tr>                <td colspan="3"><input type="submit" />                </td>            </tr>        </table>    </form:form></body></html>

If the form is submitted, render the successful page and display the submitted textbox value.

File : `CustomerSuccess.jsp`

<html><body>    <h2>Spring's form textbox example</h2>    userName : ${customer.userName}</body></html>

5. Spring Bean Configuration

Link it all ~

<beans xmlns="http://www.springframework.org/schema/beans"    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-2.5.xsd">  <bean  class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" />    <bean class="com.mkyong.customer.controller.TextBoxController">        <property name="formView" value="CustomerForm" />        <property name="successView" value="CustomerSuccess" />        <!-- Map a validator -->        <property name="validator">            <bean class="com.mkyong.customer.validator.CustomerValidator" />        </property>    </bean>    <!-- Register the Customer.properties -->    <bean id="messageSource"        class="org.springframework.context.support.ResourceBundleMessageSource">        <property name="basename" value="message" />    </bean>    <bean id="viewResolver"        class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <property name="prefix">            <value>/WEB-INF/pages/</value>        </property>        <property name="suffix">            <value>.jsp</value>        </property>    </bean></beans>