The following example describes how to use a Single Checkbox in forms using the Spring Web MVC framework. To start with, let us have a working Eclipse IDE in place and consider the following steps to develop a Dynamic Form based Web Application using the Spring Web Framework.
Step | Description |
---|---|
1 | Create a project with a name HelloWeb under a package com.howcodexas explained in the Spring MVC - Hello World Example chapter. |
2 | Create Java classes User, UserController under the com.howcodexpackage. |
3 | Create a view files user.jsp, users.jsp under jsp sub-folder. |
4 | The final step is to create the content of the source and configuration files and export the application as explained below. |
package com.howcodex; public class User { private String username; private String password; private String address; private boolean receivePaper; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public boolean isReceivePaper() { return receivePaper; } public void setReceivePaper(boolean receivePaper) { this.receivePaper = receivePaper; } }
package com.howcodex; 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 public class UserController { @RequestMapping(value = "/user", method = RequestMethod.GET) public ModelAndView user() { return new ModelAndView("user", "command", new User()); } @RequestMapping(value = "/addUser", method = RequestMethod.POST) public 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()); return "users"; } }
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.
<%@taglib uri = "http://www.springframework.org/tags/form" prefix = "form"%> <html> <head> <title>Spring MVC Form Handling</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 colspan = "2"> <input type = "submit" value = "Submit"/> </td> </tr> </table> </form:form> </body> </html>
Here, we are using <form:checkboxes /> tag to render an HTML checkbox box.
For example −
<form:checkbox path="receivePaper" />
It will render following HTML content.
<input id="receivePaper1" name = "receivePaper" type = "checkbox" value = "true"/> <input type = "hidden" name = "_receivePaper" value = "on"/>
<%@taglib uri = "http://www.springframework.org/tags/form" prefix = "form"%> <html> <head> <title>Spring MVC Form Handling</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> </table> </body> </html>
Once you are done with creating source and configuration files, export your application. Right click on your application, use Export → WAR File option and save your HelloWeb.war file in Tomcat's webapps folder.
Now, start your 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 Application.
After submitting the required information, click on the submit button to submit the form. We will see the following screen if everything is fine with the Spring Web Application.