Developing Your First Spring Web Application

Here is the steps how to setup spring webapplication

You can download the code with zip springtest.zip ..Code is ready..just download and run in tomcat.. Click donate button

Steps to run the downloded code :
step 1. unzip the downloaded zip file to D:\tomcat\webapps\ directory.
step 2. D:\tomcat\bin > stratup.bat
step 3. Go to browser and type the URL : http://localhost:8080/springtest/test/empform.do

step 4. Enter firstName and lastName and submit the "save changes" button.

Here is the code Explanation

Step 1. Set the DispatcherServlet in web.xml

DispatcherServlet

DispatcherServlet a central servlet that dispatches requests to controllers and offers other functionality facilitating the development of web applications. DispatcherServlet completely integrated with the Spring IoC container and allows you to use every other feature that Spring has.
The DispatcherServlet is an Servlet declared in the web.xml.
Consider the following DispatcherServlet servlet configuration (in the web.xml file.)

<web-app> <servlet>
<servlet-name>test</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>test</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
</web-app>

With the above servlet configuration , you will need to have a file called '/WEB-INF/test-servlet.xml' in your application.

Step 2. test-servlet.xml file

test-servlet.xml file contains viewResolver , Handler mappings and Controllers.
viewResolver :
All controllers in the Spring Web MVC framework return a ModelAndView instance. Views in Spring are addressed by a view name and are resolved by a view resolver. For Example : if your controller return new ModelAndView("empform"); means control forwared to "/WEB-INF/jsp/empform.jsp" based on below configuration.
When returning "empform" as a viewname, this view resolver will hand the request over to the RequestDispatcher that will send the request to /WEB-INF/jsp/empform.jsp.

BeanNameUrlHandlerMapping:
A very simple, but very powerful handler mapping is the BeanNameUrlHandlerMapping, which maps incoming HTTP requests to names of beans, defined in the web application context.
<bean id="defaultHandlerMapping" class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
Controllers :
<bean name="/test/empform.do" class="com.EmpFormController"/>
<bean name="/test/saveempform.do" class="com.EmpSaveController"/>
If in the browser you call http://localhost:8080/springtest/test/empform.do then EmpFormController class will be called.

Step 3. Controller classes

EmpFormController.java


				package com;


import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;


import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;



public class EmpFormController  implements Controller{
	
	public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
		System.out.println("inside EmpFormController");
		return new ModelAndView("empform"); 

//RequestDispatcher that will send the request to /WEB-INF/jsp/empform.jsp

	}

}

EmpSaveController.java


package com;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

public class EmpSaveController implements Controller{
	public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
		System.out.println("inside EmpSaveController");
		String firstName = request.getParameter("firstName");
		System.out.println("firstName"+firstName);
		String lastName = request.getParameter("lastName");
		System.out.println("lastName"+lastName);
		return new ModelAndView("success");

//RequestDispatcher that will send the request to /WEB-INF/jsp/success.jsp
}

}

Step 4. JSP code empform.jsp and success.jsp

empform.jsp

<form method="POST" action="/springtest/test/saveempform.do">
First Name:
<input name="firstName" type="text" value=""/>
Last Name:
<input name="lastName" type="text" value=""/>
<input type="submit" value="Save Changes" />
</form>

success.jsp

<h2>Emp name saved </h2>