In my previous article, we have learnt how BeanNameUrlHandlerMapping works. Now, let’s look into ControllerClassHandlerMapping, this type of HandlerMapping uses a convention to map the requested URL to the Controller. It will take the Controller name and converts them to lower case with a leading “/”
Using BeanNameUrlHandlerMapping
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
<bean name="/helloWorld.htm"
class="com.javainterviewpoint.HelloWorldController" />
<bean name="/hello*.htm"
class="com.javainterviewpoint.HelloWorldController" />
Using ControllerClassNameHandlerMapping
<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" /> <bean class="com.javainterviewpoint.HelloWorldController"></bean> <bean class="com.javainterviewpoint.WelcomeController"></bean>
When using ControllerClassNameHandlerMapping, there is no need for bean name
Folder Structure :
- Create a Dynamic Web Project “SpringMVCHandlerMappingTutorial” and create a package for our src files “com.javainterviewpoint“
- Place the Spring 3 jar files under WEB-INF/Lib
commons-logging-1.1.1.jar
log4j-1.2.16.jar
slf4j-api-1.7.5.jar
slf4j-log4j12-1.7.5.jar
spring-aspects-3.2.4.RELEASE.jar
spring-beans-3.2.4.RELEASE.jar
spring-context-3.2.4.RELEASE.jar
spring-core-3.2.4.RELEASE.jar
spring-expression-3.2.4.RELEASE.jar
spring-web-3.2.4.RELEASE.jar
spring-webmvc-3.2.4.RELEASE.jar - Create the Java classes HelloWorldController.java and WelcomeController.java under com.javainterviewpoint folder.
- Place the SpringConfig-servlet.xml and web.xml under the WEB-INF directory
- View files helloWorld.jsp and welcome.jsp are put under the sub directory under WEB-INF/Jsp
HelloWorldController.java
Our HelloWorldController class extends AbstractController class and overrides “handleRequestInternal()” method. Inside the method we will create a ModelAndView object which has the redirecting page(helloWorld) and user passes a String which will be used at the view page.
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.AbstractController;
public class HelloWorldController extends AbstractController
{
@Override
protected ModelAndView handleRequestInternal(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out.println("Inside HelloWorldController");
ModelAndView model = new ModelAndView("helloWorld");
model.addObject("msg", "JavaInterviewPoint");
return model;
}
}
WelcomeController.java
WelcomeController is almost the same as HelloWorldController except the redirecting page and the String passed.
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.AbstractController;
public class WelcomeController extends AbstractController
{
@Override
protected ModelAndView handleRequestInternal(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out.println("Inside WelcomeController");
ModelAndView model = new ModelAndView("welcome");
model.addObject("msg", "JavaInterviewPoint");
return model;
}
}
helloWorld.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h2>Hello World ${msg}</h2>
</body>
</html>
welcome.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h2> Welcome to ${msg}</h2>
</body>
</html>
web.xml
The web.xml has everything about the application that a server needs to know, which is placed under the WEB-INF directory. <servlet-name> contains the name of the SpringConfiguration, when the DispatcherServlet is initialized the framework will try to load a configuration file “[servlet-name]-servlet.xml” under the WEB-INF directory.
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <display-name>SpringMVCFormHandling</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>SpringConfig</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>SpringConfig</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
SpringConfig-servlet.xml
- The SpringConfig-servlet.xml is also placed under the WEB-INF directory.
- Here we have configured BeanNameUrlHandlerMapping as the HandlerMapping
- Each request is mapped to a Controller as well
<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">
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/Jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" />
<bean class="com.javainterviewpoint.HelloWorldController"></bean>
<bean class="com.javainterviewpoint.WelcomeController"></bean>
</beans>
In the above example where ever
- helloworld is requested, the DispatcherServlet redirects it to the HelloWorldController.
- helloworld123 is requested, the DispatcherServlet redirects it to the HelloWorldController.
- welcome is requested, the DispatcherServlet redirects it to the WelcomeController.
- welcome123 is requested, the DispatcherServlet redirects it to the WelcomeController.
- helloWorld is requested, you will get 404 error as “W” is capitalized here
Output
when HelloWorldController called
Hello World JavaInterviewPoint
when WelcomeController called
Welcome to JavaInterviewPoint
Leave a Reply