Bootstrap a Spring 3 annotation-only Java 6/Tomcat 6 app

SpringConfiguration.java

package laccetti.spring.app;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan(basePackages = "laccetti")
public class SpringConfiguration {
  // bean definitions go here
}

SpringWebConfiguration.java

package laccetti.spring.app;

import java.util.ArrayList;
import java.util.List;

import lombok.extern.slf4j.Slf4j;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
@EnableWebMvc
@Slf4j
public class SpringWebConfiguration extends WebMvcConfigurerAdapter {
  private List<HttpMessageConverter<?>> messageConverters;

  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/**").addResourceLocations("/");
  }

  @Override
  public void addViewControllers(ViewControllerRegistry registry) {
    // registry.addViewController("/").setViewName("redirect:index.html");
  }

  /**
   * The message converters for the content types we support.
   * 
   * @return the message converters; returns the same list on subsequent calls
   */
  private List<HttpMessageConverter<?>> getMessageConverters() {
    if (messageConverters == null) {
      messageConverters = new ArrayList<HttpMessageConverter<?>>();

      MappingJackson2HttpMessageConverter mappingJacksonHttpMessageConverter =
          new MappingJackson2HttpMessageConverter();
      messageConverters.add(mappingJacksonHttpMessageConverter);
    }
    return messageConverters;
  }

  @Override
  public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    converters.addAll(getMessageConverters());
  }

  @Bean
  public static PropertySourcesPlaceholderConfigurer externalizedProperties() {
    final PropertySourcesPlaceholderConfigurer props = new PropertySourcesPlaceholderConfigurer();
    props.setLocation(new ClassPathResource("app.properties"));
    props.setIgnoreResourceNotFound(true);
    return props;
  }
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <session-config>
    <session-timeout>15</session-timeout>
  </session-config>

  <listener>
    <listener-class>org.springframework.web.context.ContextCleanupListener</listener-class>
  </listener>

  <servlet>
    <description>Spring Web</description>
    <servlet-name>Spring Web</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextClass</param-name>
      <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
    </init-param>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>laccetti.spring.app.SpringConfiguration,laccetti.spring.app.SpringWebConfiguration</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>Spring Web</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>
  
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>
</web-app>