java-tutorials/spring-security-modules/spring-security-web-login/src/main/java/com/baeldung/AppInitializer.java

package com.baeldung;

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.context.support.GenericWebApplicationContext;
import org.springframework.web.filter.DelegatingFilterProxy;
import org.springframework.web.servlet.DispatcherServlet;

import javax.servlet.ServletContext;
import javax.servlet.ServletRegistration;

public class AppInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(final ServletContext sc) {

        AnnotationConfigWebApplicationContext root = new AnnotationConfigWebApplicationContext();

        root.scan("com.baeldung");
        sc.addListener(new ContextLoaderListener(root));

        ServletRegistration.Dynamic appServlet = sc.addServlet("mvc", new DispatcherServlet(new GenericWebApplicationContext()));
        appServlet.setLoadOnStartup(1);
        appServlet.addMapping("/");

        sc.addFilter("securityFilter", new DelegatingFilterProxy("springSecurityFilterChain"))
        .addMappingForUrlPatterns(null, false, "/*");

    }

}