In Spring MVC, <form:checkbox /> is used to render a HTML checkbox field, the checkbox values are hard-coded inside the JSP page; While the <form:checkboxes /> is used to render multiple checkboxes, the checkbox values are generated at runtime.

In this tutorial, we show you 3 different ways of render HTML checkbox fields:

1. <form:checkbox /> – Single Checkbox

Generate a classic single checkbox, with a boolean value.

public class Customer{
	boolean receiveNewsletter;
	//...
}
<form:checkbox path="receiveNewsletter" />
Checked by default…
If you set the “receiveNewsletter” boolean value to true, this checkbox will be checked. For example :

public class Customer{
	boolean receiveNewsletter = true;
	//...
}

2. <form:checkbox /> – Multiple Checkboxes

Generate multiple checkboxes and hard-coded the value.

public class Customer{
	String [] favLanguages;
	//...
}
<form:checkbox path="favLanguages" value="Java"/>Java 
<form:checkbox path="favLanguages" value="C++"/>C++ 
<form:checkbox path="favLanguages" value=".Net"/>.Net
Checked by default…
If you want to make the checkbox with value “Java” is checked by default, you can initialize the “favLanguages” property with value “Java”. For example :

        //SimpleFormController...
        @Override
	protected Object formBackingObject(HttpServletRequest request)
		throws Exception {
 
		Customer cust = new Customer();
		cust.setFavLanguages(new String []{"Java"});
 
		return cust;
 
	}

3. <form:checkboxes /> – Multiple Checkboxes

Generate a runtime list for the checkboxes value, and link it to Spring’s form tag <form:checkboxes>.

        //SimpleFormController...
	protected Map referenceData(HttpServletRequest request) throws Exception {
 
		Map referenceData = new HashMap();
		List<String> webFrameworkList = new ArrayList<String>();
		webFrameworkList.add("Spring MVC");
		webFrameworkList.add("Struts 1");
		webFrameworkList.add("Struts 2");
		webFrameworkList.add("Apache Wicket");
		referenceData.put("webFrameworkList", webFrameworkList);
 
		return referenceData;
	}
<form:checkboxes items="${webFrameworkList}" path="favFramework" />
Checked by default…
If you want to make 2 checkboxes with value “Spring MVC” and “Struts 2″ are checked by default, you can initialize the “favFramework” property with value “Spring MVC” and “Struts 2″. Fro example :

         //SimpleFormController...
        @Override
	protected Object formBackingObject(HttpServletRequest request)
		throws Exception {
 
		Customer cust = new Customer();
		cust.setFavFramework(new String []{"Spring MVC","Struts 2"});
 
		return cust;
	}
Note

<form:checkboxes items="${dynamic-list}" path="property-to-store" />

For multiple checkboxes, as long as the “path” or “property” value is equal to any of the “checkbox values – ${dynamic-list}“, the matched checkbox will be checked automatically.

Full checkbox example

Let’s go thought a complete Spring MVC checkbox example :

1. Model

A customer model class to store the checkbox value.

File : Customer.java

package com.mkyong.customer.model;
 
public class Customer{
 
	//checkbox
	boolean receiveNewsletter = true; //checked it
	String [] favLanguages;
	String [] favFramework;
 
	public String[] getFavFramework() {
		return favFramework;
	}
	public void setFavFramework(String[] favFramework) {
		this.favFramework = favFramework;
	}
	public boolean isReceiveNewsletter() {
		return receiveNewsletter;
	}
	public void setReceiveNewsletter(boolean receiveNewsletter) {
		this.receiveNewsletter = receiveNewsletter;
	}
	public String[] getFavLanguages() {
		return favLanguages;
	}
	public void setFavLanguages(String[] favLanguages) {
		this.favLanguages = favLanguages;
	}
}

2. Controller

A SimpleFormController to handle the form checkbox value.

File : CheckBoxController.java

package com.mkyong.customer.controller;
 
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
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 CheckBoxController extends SimpleFormController{
 
	public CheckBoxController(){
		setCommandClass(Customer.class);
		setCommandName("customerForm");
	}
 
	@Override
	protected Object formBackingObject(HttpServletRequest request)
		throws Exception {
 
		Customer cust = new Customer();
 
		//Make "Spring MVC" and "Struts 2" as default checked value
		cust.setFavFramework(new String []{"Spring MVC","Struts 2"});
 
		//Make "Java" as default checked value
		cust.setFavLanguages(new String []{"Java"});
 
		return cust;
 
	}
 
	@Override
	protected ModelAndView onSubmit(HttpServletRequest request,
		HttpServletResponse response, Object command, BindException errors)
		throws Exception {
 
		Customer customer = (Customer)command;
		return new ModelAndView("CustomerSuccess","customer",customer);
 
	}
 
	//Generate the data for web framework multiple checkboxes
	protected Map referenceData(HttpServletRequest request) throws Exception {
 
		Map referenceData = new HashMap();
		List<String> webFrameworkList = new ArrayList<String>();
		webFrameworkList.add("Spring MVC");
		webFrameworkList.add("Struts 1");
		webFrameworkList.add("Struts 2");
		webFrameworkList.add("Apache Wicket");
		referenceData.put("webFrameworkList", webFrameworkList);
 
		return referenceData;
 
	}
}

3. Validator

A simple form validator make sure the “favLanguages” property is not empty.

File : CheckBoxValidator.java

package com.mkyong.customer.validator;
 
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;
import com.mkyong.customer.model.Customer;
 
public class CheckBoxValidator 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) {
 
		Customer cust = (Customer)target;
 
		if(cust.getFavLanguages().length==0){
			errors.rejectValue("favLanguages", "required.favLanguages");
		}
	}
}

File : message.properties

required.favLanguages = Please select at least a favorite programming language!

4. View

A JSP page to show the use of Spring’s form tag <form:checkbox /> and <form:checkboxes />.

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 checkbox example</h2>
 
	<form:form method="POST" commandName="customerForm">
		<form:errors path="*" cssClass="errorblock" element="div" />
		<table>
			<tr>
				<td>Subscribe to newsletter? :</td>
				<td><form:checkbox path="receiveNewsletter" /></td>
				<td><form:errors path="receiveNewsletter" cssClass="error" /></td>
			</tr>
			<tr>
				<td>Favourite Languages :</td>
				<td>
                                       <form:checkbox path="favLanguages" value="Java" />Java 
                                       <form:checkbox path="favLanguages" value="C++" />C++ 
                                       <form:checkbox path="favLanguages" value=".Net" />.Net
                                </td>
				<td><form:errors path="favLanguages" cssClass="error" />
				</td>
			</tr>
			<tr>
				<td>Favourite Web Frameworks :</td>
				<td><form:checkboxes items="${webFrameworkList}"
						path="favFramework" /></td>
				<td><form:errors path="favFramework" cssClass="error" /></td>
			</tr>
			<tr>
				<td colspan="3"><input type="submit" /></td>
			</tr>
		</table>
	</form:form>
 
</body>
</html>

Use JSTL to loop over the submitted checkboxes value, and display it.

File : CustomerSuccess.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
 
<html>
<body>
	<h2>Spring's form checkbox example</h2>
 
	Receive Newsletter : ${customer.receiveNewsletter}
	<br />
 
         Favourite Languages :
	<c:forEach items="${customer.favLanguages}" var="current">
		[<c:out value="${current}" />]
	</c:forEach>
	<br />
 
         Favourite Web Frameworks :
	<c:forEach items="${customer.favFramework}" var="current">
		[<c:out value="${current}" />]
	</c:forEach>
	<br />
</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.CheckBoxController">
		<property name="formView" value="CustomerForm" />
		<property name="successView" value="CustomerSuccess" />
 
		<!-- Map a validator -->
		<property name="validator">
			<bean class="com.mkyong.customer.validator.CheckBoxValidator" />
		</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/checkbox.htm

SpringMVC-CheckBox-Example-1

If the user did not select any language checkboxes value while submitting the form, display and highlight the error message.

SpringMVC-CheckBox-Example-2

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

SpringMVC-CheckBox-Example-3

Download Source Code

Download it – SpringMVCForm-CheckBox-Example.zip (10KB)

References

  1. http://forum.springsource.org/showthread.php?t=80088&highlight=checkboxes
  2. http://forum.springsource.org/showthread.php?t=79133&highlight=checkboxes
  3. http://forum.springsource.org/showthread.php?t=46950&highlight=checkbox
  4. http://tomasjurman.blogspot.com/2009/12/tag-checkboxes-in-spring-mvc.html
  5. http://www.mkyong.com/struts2/how-to-set-default-value-for-multiple-checkboxes-in-struts-2/
Tags :
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