Spring MVC_demo.txt

1.

Spring MVC 

create a Maven project 

select archetype webapp

group id
artifact id
ver
pacakage

-----------------------------------------
2.

JDK 8 

Add proper Maven dependency at pom.xml

<dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-core</artifactId> 
     <version>5.0.5.RELEASE</version> 
 </dependency> 
     <!-- https://mvnrepository.com/artifact/org.springframework/spring-web --> 
 <dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-web</artifactId> 
     <version>5.0.5.RELEASE</version> 
 </dependency> 
     <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc --> 
 <dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-webmvc</artifactId> 
     <version>5.0.5.RELEASE</version> 
 </dependency> 
  <dependency>
  	<groupId>junit</groupId>
  	<artifactId>junit</artifactId>
  	<version>4.12</version>
  </dependency>
    
-------------------------------------------------
3. set the target runtime to server

-----------------------------------------
4. create a java folder under src/main if required only

src/main/java

---------------------------------------------------
5. package com.niit.springwebexample.domain;

	public interface HelloWorld {

		public String sayHello();
	}
-------------------------------------------
6. 
package com.niit.springwebexample.domain;
	
	import org.springframework.stereotype.Component;
	
        @Component("helloWorld")
	public class HelloWorldImpl implements HelloWorld{
	
        public String sayHello() {
	return "HelloWorld";
	}
	
	}

---------------------------------------------
7. 

package com.niit.springwebexample.controller;
	

	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.stereotype.Controller;
	import org.springframework.ui.Model;
	import org.springframework.web.bind.annotation.GetMapping;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RequestMethod;
	
	import com.niit.springwebexample.domain.HelloWorld;
	
	@Controller
	public class HelloController {
	

		@Autowired
		private HelloWorld helloWorld; //DI
		
		
		@GetMapping("/")
		public String hello(Model model) {
		
        	model.addAttribute("hello", helloWorld.sayHello());
		
                return "index";  // logical name for output is index

		// model here is used for preparing the data
                 }
		// every method is mapped to one url
	}

-----------------------------------------------------


8.



config :-> 2 files.


package com.niit.springwebexample.config;
	

	import org.springframework.context.annotation.Bean;
	import org.springframework.context.annotation.ComponentScan;
	import org.springframework.context.annotation.Configuration;
	import org.springframework.web.servlet.ViewResolver;
	import org.springframework.web.servlet.config.annotation.EnableWebMvc;
	import org.springframework.web.servlet.view.InternalResourceViewResolver;
	

	import com.niit.springwebexample.domain.HelloWorld;
	import com.niit.springwebexample.domain.HelloWorldImpl;
	

	@Configuration
	@EnableWebMvc
	@ComponentScan(basePackages="com.niit")
	public class AppConfig {
		
		@Bean(name="viewResolver")
		public ViewResolver getViewResolver() {
			InternalResourceViewResolver viewResolver=new                         InternalResourceViewResolver();
			viewResolver.setPrefix("/WEB-INF/views/");
			viewResolver.setSuffix(".jsp");
			
			return viewResolver;
			
		}
	

	}

----------------------------------------------------


package com.niit.springwebexample.config;
	

	import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
	

	public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{
	

		@Override
		protected Class<?>[] getRootConfigClasses() {
			// TODO Auto-generated method stub
			return new Class[] {AppConfig.class};
		}
	

		@Override
		protected Class<?>[] getServletConfigClasses() {
			// TODO Auto-generated method stub
			return null;
		}
	

		@Override
		protected String[] getServletMappings() {
			// TODO Auto-generated method stub
			return new String[] {"/"};
		}
	

	}


-----------------------------------------------


9.

Web-inf/views/

index.jsp


<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"   isELIgnored="false" %>
<%@ page session="false"%>
<html>
<body>
<h2>Hello World!</h2>
<h2>${hello}</h2>
</body>
</html>

----------------------------------------------------