Spring MVC - Hidden Field Example

The following example describes how to use a Hidden Field in forms using the Spring Web MVC framework. To start with, let us have a working Ecppse IDE in place and consider the following steps to develop a Dynamic Form based Web Apppcation using 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 Student, StudentController under the com.tutorialspoint package.
3	Create view files student.jsp, result.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.

Student.java

package com.tutorialspoint;

pubpc class Student {
   private Integer age;
   private String name;
   private Integer id;

   pubpc void setAge(Integer age) {
      this.age = age;
   }
   pubpc Integer getAge() {
      return age;
   }

   pubpc void setName(String name) {
      this.name = name;
   }
   pubpc String getName() {
      return name;
   }

   pubpc void setId(Integer id) {
      this.id = id;
   }
   pubpc Integer getId() {
      return id;
   }
}

StudentController.java

package com.tutorialspoint;

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 StudentController {

   @RequestMapping(value = "/student", method = RequestMethod.GET)
   pubpc ModelAndView student() {
      return new ModelAndView("student", "command", new Student());
   }
   
   @RequestMapping(value = "/addStudent", method = RequestMethod.POST)
   pubpc String addStudent(@ModelAttribute("SpringWeb")Student student, 
      ModelMap model) {
      model.addAttribute("name", student.getName());
      model.addAttribute("age", student.getAge());
      model.addAttribute("id", student.getId());
      
      return "result";
   }
}

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

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

student.jsp

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

      <h2>Student Information</h2>
      <form:form method = "POST" action = "/HelloWeb/addStudent">
         <table>
            <tr>
              <td><form:label path = "name">Name</form:label></td>
              <td><form:input path = "name" /></td>
            </tr>
            <tr>
              <td><form:label path = "age">Age</form:label></td>
              <td><form:input path = "age" /></td>
            </tr>
            <tr>
              <td>< </td>
              <td><form:hidden path = "id" value = "1" /></td>
            </tr>
            <tr>
              <td colspan = "2">
                  <input type = "submit" value = "Submit"/>
              </td>
            </tr>
         </table>  
      </form:form>
   </body>
</html>

Here, we are using the <form:hidden /> tag to render a HTML hidden field.

For example −

<form:hidden path = "id" value = "1"/>

It will render following HTML content.

<input id = "id" name = "id" type = "hidden" value = "1"/>

result.jsp

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

      <h2>Submitted Student Information</h2>
      <table>
         <tr>
            <td>Name</td>
            <td>${name}</td>
         </tr>
         <tr>
            <td>Age</td>
            <td>${age}</td>
         </tr>
         <tr>
            <td>ID</td>
            <td>${id}</td>
         </tr>
      </table>  
   </body>
</html>

Once you are done with creating source and configuration files, export your apppcation. Right cpck on your apppcation and 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/student 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 - Hidden Field Example

Student.java

StudentController.java

student.jsp

result.jsp

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