Bootstrapping Using spring-webmvc

 Bootstrapping Using spring-webmvc

Maven Dependencies

First, we need the spring-webmvc dependency:

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.0.0.RELEASE</version>

</dependency

						
The Java-based Web Configuration						
Next, we’ll add the configuration class that has the @Configuration
annotation:						
								
@Configuration
								
@EnableWebMvc								
@ComponentScan(basePackages = “com.baeldung.controller”)
public class WebConfig {	

		 }

											
Here, unlike the Spring Boot solution, we’ll have to explicitly define
@EnableWebMvc for setting up default Spring MVC Configurations and
@ComponentScan to specify packages to scan for components.

						
The @EnableWebMvc annotation provides the Spring Web MVC
configuration such as setting up the dispatcher servlet, enabling the @
Controller and the @RequestMapping annotations and setting up other
defaults.

						
@ComponentScan configures the component scanning directive, specifying
the packages to scan.					
			
Next, we need to add a class that implements the
WebApplicationInitializer interface:

					
						
public class AppInitializer implements WebApplicationInitializer {
					
    @Override
    public void onStartup(ServletContext container) throws ServletException {
					
        AnnotationConfigWebApplicationContext context = new
AnnotationConfigWebApplicationContext();
					
        context.scan(“com.baeldung”);
        container.addListener(new ContextLoaderListener(context));
						
        ServletRegistration.Dynamic dispatcher =
          container.addServlet(“mvc”, new DispatcherServlet(context));
						
        dispatcher.setLoadOnStartup(1);
						
        dispatcher.addMapping(“/”);
    }

						
}

					

						
Here, we’re creating a Spring context using the
AnnotationConfigWebApplicationContext class, which means we’re
using only annotation-based configuration. Then, we’re specifying the
packages to scan for components and configuration classes.

						
Finally, we’re defining the entry point for the web application – the
DispatcherServlet.

						
This class can entirely replace the web.xml file from <3.0 Servlet versions.
			

				

					

						
XML Configuration

					
				
			
						
Let’s also have a quick look at the equivalent XML web configuration:
								
<context:component-scan base-package=”com.baeldung.controller” />		
<mvc:annotation-driven />

		
						
We can replace this XML file with the WebConfig class above.

						
To start the application, we can use an Initializer class that loads the XML
configuration or a web.xml file.