Spring MVC - Hibernate Vapdator Example

The following example shows how to use Error Handpng and Vapdators in forms using the Spring Web MVC framework. To begin with, let us have a working Ecppse IDE in place and adhere to the following steps to develop a Dynamic Form based Web Apppcation using the Spring Web Framework.

Student.java

package com.tutorialspoint;

import org.hibernate.vapdator.constraints.NotEmpty;
import org.hibernate.vapdator.constraints.Range;

pubpc class Student {

   @Range(min = 1, max = 150) 
   private Integer age;
   @NotEmpty
   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.ui.Model;
import org.springframework.vapdation.BindingResult;
import org.springframework.vapdation.annotation.Vapdated;
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;

@Controller
pubpc class StudentController {

   @RequestMapping(value = "/addStudent", method = RequestMethod.GET)
   pubpc ModelAndView student() {
      return new ModelAndView("addStudent", "command", new Student());
   }

   @ModelAttribute("student")
   pubpc Student createStudentModel() {	
      return new Student();
   }

   @RequestMapping(value = "/addStudent", method = RequestMethod.POST)
   pubpc String addStudent(@ModelAttribute("student") @Vapdated Student student, 
      BindingResult bindingResult, Model model) {
      if (bindingResult.hasErrors()) {
         return "addStudent";
      }
      model.addAttribute("name", student.getName());
      model.addAttribute("age", student.getAge());
      model.addAttribute("id", student.getId());

      return "result";
   }
}

messages.properties

NotEmpty.student.name = Name is required!
Range.student.age = Age value must be between 1 and 150!

Here, the key is <Annotation>.<object-name>.<attribute>. Value is the message to be displayed.

TestWeb-servlet.xml

<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:context = "http://www.springframework.org/schema/context"
   xmlns:mvc = "http://www.springframework.org/schema/mvc"
   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-3.0.xsd
   http://www.springframework.org/schema/context 
   http://www.springframework.org/schema/context/spring-context-3.0.xsd
   http://www.springframework.org/schema/mvc
   http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

   <context:component-scan base-package = "com.tutorialspoint" />
   <mvc:annotation-driven />
   <bean class = "org.springframework.context.support.ResourceBundleMessageSource"
      id = "messageSource">
      <property name = "basename" value = "messages" />
   </bean>
   <bean class = "org.springframework.web.servlet.view.InternalResourceViewResolver">
      <property name = "prefix" value = "/WEB-INF/jsp/" />
      <property name = "suffix" value = ".jsp" />      
   </bean>
</beans>

Here, for the first service method student(), we have passed a blank Studentobject> 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 student() method is called, it returns addStudent.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 the result.jsp. In case there are errors generated using vapdator then same view "addStudent" is returned, Spring automatically injects error messages from BindingResult in view.

addStudent.jsp

<%@tagpb uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
   <head>
      <title>Spring MVC Form Handpng</title>
   </head>
   <style>
      .error {
         color: #ff0000;
      }

      .errorblock {
         color: #000;
         background-color: #ffEEEE;
         border: 3px sopd #ff0000;
         padding: 8px;
         margin: 16px;
      }
   </style>
   <body>

      <h2>Student Information</h2>
      <form:form method = "POST" action = "/TestWeb/addStudent" commandName = "student">
      <form:errors path = "*" cssClass = "errorblock" element = "span" />
         <table>
            <tr>
               <td><form:label path = "name">Name</form:label></td>
               <td><form:input path = "name" /></td>
               <td><form:errors path = "name" cssClass = "error" /></td>
            </tr>
            <tr>
               <td><form:label path = "age">Age</form:label></td>
               <td><form:input path = "age" /></td>
               <td><form:errors path = "age" cssClass = "error" /></td>
            </tr>
            <tr>
               <td><form:label path = "id">id</form:label></td>
               <td><form:input path = "id" /></td>
               </tr>
            <tr>
               <td colspan = "2">
               <input type = "submit" value = "Submit"/>
               </td>
            </tr>
         </table>  
      </form:form>
   </body>
</html>

Here, we are using the <form:errors /> tag with path="*" to render error messages. For example −

<form:errors path = "*" cssClass = "errorblock" element = "span" />

It will render error messages for all input vapdations. We are using <form:errors /> tag with path = "name" to render error message for the name field.

For example −

<form:errors path = "name" cssClass = "error" />
<form:errors path = "age" cssClass = "error" />

It will render error messages for name and age field vapdations.

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, use Export → WAR File option and save the HelloWeb.war file in Tomcat s webapps folder.

Now, start the Tomcat server and make sure you are able to access other webpages from the webapps folder using a standard browser. Try a URL − http://localhost:8080/TestWeb/addStudent and we will see the following screen, if you have entered invapd values.