Spring MVC - Checkboxes Example

The following example explains how to use Multiple Checkboxes in forms using the Spring Web MVC framework. To start with, let us have a working Ecppse IDE in place and stick to the following steps to develop a Dynamic Form based Web Apppcation using the Spring Web Framework.

Step	Description
1	Create a project with a name HelloWeb under a package com.tutorialspoint as explained in the Spring MVC - Hello World chapter.
2	Create Java classes User, UserController under the com.tutorialspointpackage.
3	Create view files user.jsp, users.jsp under the jsp sub-folder.
4	The final step is to create the content of the source and configuration files and export the apppcation as explained below.

User.java

package com.tutorialspoint;

pubpc class User {
	
   private String username;
   private String password;
   private String address;
   private boolean receivePaper;
   private String [] favoriteFrameworks;   

   pubpc String getUsername() {
      return username;
   }
   pubpc void setUsername(String username) {
      this.username = username;
   }

   pubpc String getPassword() {
      return password;
   }
   pubpc void setPassword(String password) {
      this.password = password;
   }
   pubpc String getAddress() {
      return address;
   }
   pubpc void setAddress(String address) {
      this.address = address;
   }
   pubpc boolean isReceivePaper() {
      return receivePaper;
   }
   pubpc void setReceivePaper(boolean receivePaper) {
      this.receivePaper = receivePaper;
   }
   pubpc String[] getFavoriteFrameworks() {
      return favoriteFrameworks;
   }
   pubpc void setFavoriteFrameworks(String[] favoriteFrameworks) {
      this.favoriteFrameworks = favoriteFrameworks;
   }
}

UserController.java

package com.tutorialspoint;

import java.util.ArrayList;
import java.util.List;

import org.springframework.stereotype.Controller;
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 org.springframework.ui.ModelMap;

@Controller
pubpc class UserController {

   @RequestMapping(value = "/user", method = RequestMethod.GET)
   pubpc ModelAndView user() {
      User user = new User();	  
	  user.setFavoriteFrameworks((new String []{"Spring MVC","Struts 2"}));
	  ModelAndView modelAndView = new ModelAndView("user", "command", user);
	  return modelAndView;
   }

   @RequestMapping(value = "/addUser", method = RequestMethod.POST)
   pubpc String addUser(@ModelAttribute("SpringWeb")User user, 
      ModelMap model) {
      model.addAttribute("username", user.getUsername());
      model.addAttribute("password", user.getPassword());
      model.addAttribute("address", user.getAddress());
      model.addAttribute("receivePaper", user.isReceivePaper());
	  model.addAttribute("favoriteFrameworks", user.getFavoriteFrameworks());
      return "users";
   }
   
   @ModelAttribute("webFrameworkList")
   pubpc List<String> getWebFrameworkList() {
      List<String> webFrameworkList = new ArrayList<String>();
      webFrameworkList.add("Spring MVC");
      webFrameworkList.add("Struts 1");
      webFrameworkList.add("Struts 2");
      webFrameworkList.add("Apache Wicket");
      return webFrameworkList;
   }
}

Here, for the first service method user(), we have passed a blank User object in the ModelAndView object with name "command", because the spring framework expects an object with name "command", if you are using <form:form> tags in your JSP file. So, when the user() method is called, it returns the user.jsp view.

The second service method addUser() will be called against a POST method on the HelloWeb/addUser URL. You will prepare your model object based on the submitted information. Finally, the "users" view will be returned from the service method, which will result in rendering the users.jsp

user.jsp

<%@tagpb uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
   <head>
      <title>Spring MVC Form Handpng</title>
   </head>
   <body>

      <h2>User Information</h2>
      <form:form method = "POST" action = "/HelloWeb/addUser">
         <table>
            <tr>
               <td><form:label path = "username">User Name</form:label></td>
               <td><form:input path = "username" /></td>
            </tr>
            <tr>
               <td><form:label path = "password">Age</form:label></td>
               <td><form:password path = "password" /></td>
            </tr>  
            <tr>
               <td><form:label path = "address">Address</form:label></td>
               <td><form:textarea path = "address" rows = "5" cols = "30" /></td>
            </tr>  
            <tr>
               <td><form:label path = "receivePaper">Subscribe Newsletter</form:label></td>
               <td><form:checkbox path = "receivePaper" /></td>
            </tr> 
            <tr>
               <td><form:label path = "favoriteFrameworks">Favorite Web Frameworks</form:label></td>
               <td><form:checkboxes items = "${webFrameworkList}" path = "favoriteFrameworks" /></td>       
            </tr> 
            <tr>
               <td colspan = "2">
                  <input type = "submit" value = "Submit"/>
               </td>
            </tr>
         </table>  
      </form:form>
   </body>
</html>

Here, we are using <form:checkboxes /> tag to render HTML checkboxes.

<form:checkboxes items = "${webFrameworkList}" path = "favoriteFrameworks" />

It will render following HTML content.

<span>
   <input id = "favoriteFrameworks1" name = "favoriteFrameworks" type = "checkbox" value = "Spring MVC" checked = "checked"/>
   <label for = "favoriteFrameworks1">Spring MVC</label>
</span>
<span>
   <input id = "favoriteFrameworks2" name = "favoriteFrameworks" type = "checkbox" value = "Struts 1"/>
   <label for = "favoriteFrameworks2">Struts 1</label>
</span>
<span>
   <input id = "favoriteFrameworks3" name = "favoriteFrameworks" type = "checkbox" value = "Struts 2" checked = "checked"/>
   <label for = "favoriteFrameworks3">Struts 2</label>
</span>
<span>
   <input id = "favoriteFrameworks4" name = "favoriteFrameworks" type = "checkbox" value = "Apache Wicket"/>
   <label for = "favoriteFrameworks4">Apache Wicket</label>
</span>
<input type = "hidden" name = "_favoriteFrameworks" value = "on"/>

users.jsp

<%@tagpb uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
   <head>
      <title>Spring MVC Form Handpng</title>
   </head>
   <body>

      <h2>Submitted User Information</h2>
      <table>
         <tr>
            <td>Username</td>
            <td>${username}</td>
         </tr>
         <tr>
            <td>Password</td>
            <td>${password}</td>
         </tr>    
         <tr>
            <td>Address</td>
            <td>${address}</td>
         </tr>  
         <tr>
            <td>Subscribed to Newsletter</td>
            <td>${receivePaper}</td>
         </tr>    
         <tr>
            <td>Favorite Web Frameworks</td>
            <td> <% String[] favoriteFrameworks = (String[])request.getAttribute("favoriteFrameworks");
            for(String framework: favoriteFrameworks) {
               out.println(framework);
            }
            %></td>
         </tr>     	  
      </table>  
   </body>
</html>

Once you are done with creating source and configuration files, export your apppcation. Right cpck on your apppcation, use Export → WAR File option and save your HelloWeb.war file in Tomcat s webapps folder.

Now, start the Tomcat server and make sure you are able to access other webpages from webapps folder using a standard browser. Try a URL http://localhost:8080/HelloWeb/user and we will see the following screen if everything is fine with the Spring Web Apppcation.

After submitting the required information, cpck on the submit button to submit the form. We will see the following screen, if everything is fine with your Spring Web Apppcation.

Spring MVC - Checkboxes Example

User.java

UserController.java

user.jsp

users.jsp

友情链接