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Spring MVC textarea example

2015-09-14 10:54 633 查看

In Spring MVC, use

<form:textarea />

to render a HTML textarea field. For example,

<form:textarea path="address" rows="5" cols="30" />

It will render the following HTML code

<textarea id="address" name="address" rows="5" cols="30"></textarea>

In this tutorial, we show you how to use Spring’s form tag “

textarea

” to render a HTML textarea to store the “

address

“. Additionally, add a validator to make sure the texarea is not empty while submitting the form.

1. Controller

SimpleFormController

to handle the form value.

File :

TextAreaController.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 TextAreaController extends SimpleFormController{

public TextAreaController(){
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

Customer

object to store the textarea value.

File :

Customer.java

package com.mkyong.customer.model;

public class Customer{

String address;
//getter and setter methods for address
}

3. Form Validator

Create a form validator class and use the

ValidationUtils

class to make sure the “address” is not empty, Otherwise, get the “

required.address

” 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, "address",
"required.address", "Field name is required.");

}
}

File :

message.properties

required.address = Address is required!

4. View

A JSP page to use the Spring’s form tag “

textarea

” to render a HTML textarea, 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 textarea example</h2>

<form:form method="POST" commandName="customerForm">
<form:errors path="*" cssClass="errorblock" element="div" />
<table>
<tr>
<td>Address :</td>
<td><form:textarea path="address" rows="5" cols="30" /></td>
<td><form:errors path="address" 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 textarea value.

File :

CustomerSuccess.jsp

<html>
<body>
<h2>Spring's form textarea example</h2>

Address : ${customer.address}

</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.TextAreaController">
<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>

6. Demo

Access the page – http://localhost:8080/SpringMVCForm/textarea.htm

If the textarea value is empty while submitting the form, display and highlight the error message.

If the form is submitted successfully, just display the submitted textarea value.

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标签： spring mvc html spring mvc it

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