Basic Cross Origin Resource Sharing (CORS) support

CorisFilter.java

package org.springframework.web.servlet.support;

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", "Authorization");        
            response.addHeader("Access-Control-Max-Age", "1728000");
        }
        filterChain.doFilter(request, response);
    }

}

// example web.xml configuration

/*
  <filter>
    <filter-name>cors</filter-name>
    <filter-class>org.springframework.web.servlet.support.CorsFilter</filter-class>
  </filter>
  
  <filter-mapping>
    <filter-name>cors</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
*/

if (request.getHeader("Access-Control-Request-Method") != null && "OPTIONS".equals(request.getMethod()));
from the above code, why did you put semi-colon at the end of the if statement? That semi-colon confused me a lot.

and why did you surrounded other codes with {}?
{
// 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-Max-Age", "1728000");
}
like this...

it looks like that codes in the {} belong to the if statement...
So much confusing code because of the "semi-colon" after the if statement's condition...

Did you do that for any purpose? or just a mistake? I still don't understand..

I think the ; after the if is a typo just as Coris instead of Cors in the name.

Simply adding this class doesn't solve the problem.