automatically add header to every response

I recently got into this issue and found this solution.
You can use a filter to add these headers :

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.filter.OncePerRequestFilter;

public class CorsFilter extends OncePerRequestFilter {

    @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())) {
                // CORS "pre-flight" request
                response.addHeader("Access-Control-Allow-Methods",
                        "GET, POST, PUT, DELETE");
                response.addHeader("Access-Control-Allow-Headers",
                        "X-Requested-With,Origin,Content-Type, Accept");
            }
            filterChain.doFilter(request, response);
    }

}

Don’t forget add the filter to your spring context:

<bean id="corsFilter" class="my.package.CorsFilter" />

and the mapping in the web.xml:

<filter>
    <filter-name>corsFilter</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>

<filter-mapping>
    <filter-name>corsFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

To go a little further you can specify a Spring profile to enable or disable this filter with something like that:

<beans profile="!cors">
    <bean id="corsFilter" class="my.package.FilterChainDoFilter" />
</beans>

<beans profile="cors">
    <bean id="corsFilter" class="my.package.CorsFilter" />
</beans>

(providing the FilterChainDoFilter similar to the CorsFilter but which only does filterChain.doFilter(request, response); in the doFilterInternal(..))

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