automatically add header to every response

Question

I want to add this header "Access-Control-Allow-Origin", "*" to every response made to the client whenever a request has made for rest controllers in my application to allow cross origin resource sharing Currently I 'm manually adding this header to each and every method like this

HttpHeaders headers = new HttpHeaders();
headers.add("Access-Control-Allow-Origin", "*");

Its working but its very frustrating . I found webContentInterceptor in spring docs which allow us to modify headers on each response

<mvc:interceptors>
<bean id="webContentInterceptor" 
class="org.springframework.web.servlet.mvc.WebContentInterceptor">
<property name="Access-Control-Allow-Origin" value="*"/>
</bean>
</mvc:interceptors>

but when i use this it throws error that property not found of name Access-Control-Allow-Origin so is there any other way we can automatically add header to every response

Update ! Spring framework 4.2 greatly simplifies this by adding @CrossOrigin annotation to either a method or a controller itself https://spring.io/blog/2015/06/08/cors-support-in-spring-framework

Answer 1

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(..))