To enable CORS support in Spring MVC 4 - Access-Control-Allow-Origin

CORSFilter.java

package com.alkhodiry.mb.rest.filters;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.web.filter.OncePerRequestFilter;

/**
 * Enabling CORS support  - Access-Control-Allow-Origin
 * @author zeroows@gmail.com
 * 
 * <code>
 	<!-- Add this to your web.xml to enable "CORS" -->
	<filter>
	  <filter-name>cors</filter-name>
	  <filter-class>com.elm.mb.rest.filters.CORSFilter</filter-class>
	</filter>
	  
	<filter-mapping>
	  <filter-name>cors</filter-name>
	  <url-pattern>/*</url-pattern>
	</filter-mapping>
 * </code>
 */
public class CORSFilter extends OncePerRequestFilter {
	private static final Log LOG = LogFactory.getLog(CORSFilter.class);

	@Override
	protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
		response.addHeader("Access-Control-Allow-Origin", "*");
		
		if (request.getHeader("Access-Control-Request-Method") != null && "OPTIONS".equals(request.getMethod())) {
			LOG.trace("Sending Header....");
			// CORS "pre-flight" request
			response.addHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE");
//			response.addHeader("Access-Control-Allow-Headers", "Authorization");
            response.addHeader("Access-Control-Allow-Headers", "Content-Type");
			response.addHeader("Access-Control-Max-Age", "1");
		}
		
		filterChain.doFilter(request, response);
	}

}

Where shall we put that class?

Funiona ! me ha salvado el dia gracias.

Thank you so much. You saved my day !!!!!!

Awesome...

is it really needed?

Spring has its own configuration: https://docs.spring.io/spring/docs/4.2.x/spring-framework-reference/html/cors.html
As well as Tomcat: https://tomcat.apache.org/tomcat-8.0-doc/config/filter.html#CORS_Filter