Spring Boot CORS Not Working?

For the life of me I could not get the CORS Configuration for Spring Boot to write the needed headers to the response. I wrote my own filter that could read the CORS Config and used it in WebMVC Configuration to solve it.

	package com.dronze.app;
	import com.dronze.filter.CorsFilter;
	import org.springframework.beans.factory.annotation.Value;
	import org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration;
	import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory;
	import org.springframework.boot.context.embedded.FilterRegistrationBean;
	import org.springframework.boot.context.embedded.ServletRegistrationBean;
	import org.springframework.boot.context.embedded.jetty.JettyEmbeddedServletContainerFactory;
	import org.springframework.context.annotation.Bean;
	import org.springframework.context.annotation.ComponentScan;
	import org.springframework.context.annotation.Configuration;
	import org.springframework.context.annotation.PropertySource;
	import org.springframework.web.cors.CorsConfiguration;
	import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
	import org.springframework.web.servlet.DispatcherServlet;
	/**
	* Created by claytongraham on 10/25/15.
	*/
	@Configuration
	@ComponentScan(basePackages = {"com.dronze"})
	@PropertySource("classpath:/application-${dronze.env:dev}.properties")
	public class AppConfig {
	@Bean
	public EmbeddedServletContainerFactory servletContainer() {
	JettyEmbeddedServletContainerFactory server = new JettyEmbeddedServletContainerFactory();
	return server;
	}
	@Bean
	public DispatcherServlet dispatcherServlet() {
	return new DispatcherServlet();
	}
	@Bean
	public ServletRegistrationBean dispatcherServletRegistration() {
	ServletRegistrationBean registration = new ServletRegistrationBean(
	dispatcherServlet(), "/rest/api/*");
	registration.setName(DispatcherServletAutoConfiguration.DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME);
	return registration;
	}
	@Bean
	public FilterRegistrationBean corsFilter() {
	UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
	CorsConfiguration config = new CorsConfiguration();
	config.setAllowCredentials(true);
	config.addAllowedOrigin("*");
	config.addAllowedHeader("Content-Type");
	config.addAllowedMethod("OPTIONS");
	config.addAllowedMethod("GET");
	config.addAllowedMethod("PUT");
	config.addAllowedMethod("POST");
	config.addAllowedMethod("DELETE");
	source.registerCorsConfiguration("/**", config);
	final FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
	bean.setOrder(0);
	return bean;
	}
	}

view raw AppConfig.java hosted with ❤ by GitHub

	package com.dronze.filter;
	/**
	* Custom Filter Created by claytongraham on 4/19/16.
	*/
	import com.amazonaws.util.StringUtils;
	import org.springframework.http.HttpHeaders;
	import org.springframework.util.Assert;
	import org.springframework.web.cors.*;
	import org.springframework.web.filter.OncePerRequestFilter;
	import java.io.*;
	import javax.servlet.*;
	import javax.servlet.http.*;
	import java.util.*;
	public class CorsFilter extends OncePerRequestFilter {
	public static final String CUSTOM_ALLOW_CORS_HEADER = "Accept-Cors-Requests-Origin";
	private CorsProcessor processor = new DefaultCorsProcessor();
	private final CorsConfigurationSource configSource;
	/**
	* Constructor accepting a {@link CorsConfigurationSource} used by the filter to find
	* the {@link org.springframework.web.cors.CorsConfiguration} to use for each incoming request.
	* @see org.springframework.web.cors.UrlBasedCorsConfigurationSource
	*/
	public CorsFilter(CorsConfigurationSource configSource) {
	this.configSource = configSource;
	}
	/**
	* Configure a custom {@link CorsProcessor} to use to apply the matched
	* {@link org.springframework.web.cors.CorsConfiguration} for a request.
	* <p>By default {@link DefaultCorsProcessor} is used.
	*/
	public void setCorsProcessor(CorsProcessor processor) {
	Assert.notNull(processor, "CorsProcessor must not be null");
	this.processor = processor;
	}
	public static boolean isCorsRequest(HttpServletRequest request) {
	return (!StringUtils.isNullOrEmpty(request.getHeader(HttpHeaders.ORIGIN)));
	}
	private String getCSVList(List<String> items){
	String[] array = (String[])items.toArray(new String[items.size()]);
	return StringUtils.join(",", array);
	}
	@Override
	protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
	FilterChain filterChain) throws ServletException, IOException {
	CorsConfiguration corsConfiguration = configSource.getCorsConfiguration(request);
	if(isCorsRequest(request)){
	response.addHeader("Access-Control-Allow-Origin", getCSVList(corsConfiguration.getAllowedOrigins()));
	response.addHeader("Access-Control-Allow-Headers", getCSVList(corsConfiguration.getAllowedHeaders()));
	response.addHeader("Access-Control-Allow-Methods", getCSVList(corsConfiguration.getAllowedMethods()));
	}
	filterChain.doFilter(request, response);
	}
	}

view raw CorsFilter.java hosted with ❤ by GitHub