package com.atlassian.plugins.rest.module.filter;
   
   import com.atlassian.plugins.rest.common.security.CorsHeaders;
   import com.atlassian.plugins.rest.common.security.jersey.CorsResourceFilter;
   import com.sun.jersey.spi.container.ContainerRequest;
   import com.sun.jersey.spi.container.ContainerRequestFilter;
   
   import javax.ws.rs.HttpMethod;
   import javax.ws.rs.ext.Provider;
  
  import static com.atlassian.plugins.rest.common.security.jersey.CorsResourceFilter.extractOrigin;
  
  /**
   * This is a filter to force Jersey to handle OPTIONS when part of a preflight cors check.
   *
   * @since 2.6
   */
  @Provider
  public class CorsAcceptOptionsPreflightFilter implements ContainerRequestFilter {
      public ContainerRequest filter(final ContainerRequest request) {
          if (request.getMethod().equals(HttpMethod.OPTIONS)) {
              String origin = extractOrigin(request);
              String targetMethod = request.getHeaderValue(CorsHeaders.ACCESS_CONTROL_REQUEST_METHOD.value());
              if (targetMethod != null && origin != null) {
                  request.setMethod(targetMethod);
                  request.getProperties().put(CorsResourceFilter.CORS_PREFLIGHT_REQUESTED, "true");
              }
          }
          return request;
      }
  }