Tuesday, May 21, 2013

FORM HANDLING IN MVC


Spring MVC Form Handling Example




StepDescription
1Create a Dynamic Web Project with a name HelloWeb and create a packagecom.tutorialspoint under the src folder in the created project.
2Drag and drop below mentioned Spring and other libraries into the folder WebContent/WEB-INF/lib.
3Create a Java classes Student and StudentController under the com.tutorialspoint package.
4Create Spring configuration files Web.xml and HelloWeb-servlet.xml under theWebContent/WEB-INF folder.
5Create a sub-folder with a name jsp under the WebContent/WEB-INF folder. Create a view files student.jsp and result.jsp under this sub-folder.
6The final step is to create the content of all the source and configuration files and export the application as explained below.
Here is the content of Student.java file:
package com.tutorialspoint;

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

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

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

   public void setId(Integer id) {
      this.id = id;
   }
   public Integer getId() {
      return id;
   }
}
Following is the content of StudentController.java file:
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
public class StudentController {

   @RequestMapping(value = "/student", method = RequestMethod.GET)
   public ModelAndView student() {
      return new ModelAndView("student", "command", new Student());
   }
   
   @RequestMapping(value = "/addStudent", method = RequestMethod.POST)
   public 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 the first service method student(), we have passed a blank Student 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 student() method is called it returnsstudent.jsp view.
Second service method addStudent() will be called against a POST method on theHelloWeb/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
Following is the content of Spring Web configuration file web.xml
<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
 
    <display-name>Spring MVC Form Handling</display-name>
 
    <servlet>
        <servlet-name>HelloWeb</servlet-name>
        <servlet-class>
           org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>HelloWeb</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
 
</web-app>
Following is the content of another Spring Web configuration file HelloWeb-servlet.xml
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:context="http://www.springframework.org/schema/context"
   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">

   <context:component-scan base-package="com.tutorialspoint" />

   <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
      <property name="prefix" value="/WEB-INF/jsp/" />
      <property name="suffix" value=".jsp" />
   </bean>
 
</beans>
Following is the content of Spring view file student.jsp
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<html>
<head>
    <title>Spring MVC Form Handling</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><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>
Following is the content of Spring view file result.jsp
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<html>
<head>
    <title>Spring MVC Form Handling</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>
Finally, following is the list of Spring and other libraries to be included in your web application. You simply drag these files and drop them in WebContent/WEB-INF/lib folder.
  • commons-logging-x.y.z.jar
  • org.springframework.asm-x.y.z.jar
  • org.springframework.beans-x.y.z.jar
  • org.springframework.context-x.y.z.jar
  • org.springframework.core-x.y.z.jar
  • org.springframework.expression-x.y.z.jar
  • org.springframework.web.servlet-x.y.z.jar
  • org.springframework.web-x.y.z.jar
  • spring-web.jar
Once you are done with creating source and configuration files, export your application. Right click on your application and use Export > WAR File option and save your SpringWeb.war file in Tomcat'swebapps folder.
Now start your Tomcat server and make sure you are able to access other web pages from webapps folder using a standard browser. Now try a URL http://localhost:8080/SpringWeb/student and you should see the following result if everything is fine with your Spring Web Application:
Spring Student Form
After submitting required information click on submit button to submit the form. You should see the following result if everything is fine with your Spring Web Application:
Spring Student Form Result

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