WebConfigurer.java

package com.tinesoft.droidlinguist.server.config;

import java.util.Arrays;
import java.util.EnumSet;

import javax.servlet.DispatcherType;
import javax.servlet.FilterRegistration;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer;
import org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer;
import org.springframework.boot.context.embedded.MimeMappings;
import org.springframework.boot.context.embedded.ServletContextInitializer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;

import com.tinesoft.droidlinguist.server.filter.CachingHttpHeadersFilter;
import com.tinesoft.droidlinguist.server.filter.StaticResourcesProductionFilter;

/**
 * Configuration of web application with Servlet 3.0 APIs.
 */
@Configuration
public class WebConfigurer implements ServletContextInitializer, EmbeddedServletContainerCustomizer
{

	private final Logger log = LoggerFactory.getLogger(WebConfigurer.class);

	@Autowired
	private Environment env;

	@Autowired
	private DroidLinguistProperties props;

	@Override
	public void onStartup(ServletContext servletContext) throws ServletException
	{
		log.info("Web application configuration, using profiles: {}", Arrays.toString(env.getActiveProfiles()));
		EnumSet<DispatcherType> disps = EnumSet.of(DispatcherType.REQUEST, DispatcherType.FORWARD, DispatcherType.ASYNC);

		if (env.acceptsProfiles(Constants.SPRING_PROFILE_PRODUCTION))
		{
			initCachingHttpHeadersFilter(servletContext, disps);
			initStaticResourcesProductionFilter(servletContext, disps);
		}
		log.info("Web application fully configured");
	}

	/**
	 * Set up Mime types.
	 */
	@Override
	public void customize(ConfigurableEmbeddedServletContainer container)
	{
		MimeMappings mappings = new MimeMappings(MimeMappings.DEFAULT);
		// IE issue, see https://github.com/jhipster/generator-jhipster/pull/711
		mappings.add("html", "text/html;charset=utf-8");
		// CloudFoundry issue, see
		// https://github.com/cloudfoundry/gorouter/issues/64
		mappings.add("json", "text/html;charset=utf-8");
		container.setMimeMappings(mappings);
	}

	/**
	 * Initializes the static resources production Filter.
	 */
	private void initStaticResourcesProductionFilter(ServletContext servletContext, EnumSet<DispatcherType> disps)
	{

		log.debug("Registering static resources production Filter");
		FilterRegistration.Dynamic staticResourcesProductionFilter = servletContext.addFilter("staticResourcesProductionFilter",
				new StaticResourcesProductionFilter());

		staticResourcesProductionFilter.addMappingForUrlPatterns(disps, true, "/");
		staticResourcesProductionFilter.addMappingForUrlPatterns(disps, true, "/index.html");
		staticResourcesProductionFilter.addMappingForUrlPatterns(disps, true, "/assets/*");
		staticResourcesProductionFilter.addMappingForUrlPatterns(disps, true, "/scripts/*");
		staticResourcesProductionFilter.setAsyncSupported(true);
	}

	/**
	 * Initializes the caching HTTP Headers Filter.
	 */
	private void initCachingHttpHeadersFilter(ServletContext servletContext, EnumSet<DispatcherType> disps)
	{
		log.debug("Registering Caching HTTP Headers Filter");
		FilterRegistration.Dynamic cachingHttpHeadersFilter = servletContext.addFilter("cachingHttpHeadersFilter", new CachingHttpHeadersFilter(env));

		cachingHttpHeadersFilter.addMappingForUrlPatterns(disps, true, "/dist/assets/*");
		cachingHttpHeadersFilter.addMappingForUrlPatterns(disps, true, "/dist/scripts/*");
		cachingHttpHeadersFilter.setAsyncSupported(true);
	}

	@Bean
	public CorsFilter corsFilter()
	{
		UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
		CorsConfiguration config = props.getCors();
		if (config.getAllowedOrigins() != null && !config.getAllowedOrigins().isEmpty())
		{
			source.registerCorsConfiguration("/api/**", config);

		}
		return new CorsFilter(source);
	}

}