Angular2 IE11缓存问题

Question

I have an caching problem every time I do simple CORS get request on IE. This is not happening on Chrome. So i had to add options on get request:

            let options = new RequestOptions({
                url: this.elementsUrl,
                method: RequestMethod.Get,
                headers: this.getHeaders
            });
            return this.http.get(this.elementsUrl, options)
                .map(response => response.json())
                .catch(error => {
                        console.error('Error', error);
                        return Promise.reject(error.message || error);
                    }
                );

And I set headers to disable cache.

    private _getHeaders = new Headers({
    'If-Modified-Since': 'Mon, 26 Jul 1997 05:00:00 GMT',
    'Cache-Control': 'no-cache',
    'Pragma': 'no-cache'
});

And now I am getting info required CORS preflight and XMLHttpRequest: Network Error 0x80070005, Access is denied. Can I avoid triggering preflight options? Am I setting options correctly?

It's only related to IE that do caching of GET request. CORS is working OK on chrome. On server side is set: Access-Control-Allow-Origin: *

Answer 1

On server side in case of JAVA I have created a filter as below

@PreMatching
@Provider
public class GwsApiCorsFilter implements ContainerRequestFilter {

    @Override
    public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext)
            throws IOException {
        responseContext.getHeaders().add("Access-Control-Allow-Origin", "*");
        responseContext.getHeaders().add("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT, PATCH");
        responseContext.getHeaders().add("Access-Control-Allow-Headers", getAllowedHeaders());
        responseContext.getHeaders().add("Access-Control-Expose-Headers", getAllowedHeaders());

    }

    private String getAllowedHeaders() {
        StringBuilder sb = new StringBuilder();
        sb.append(HttpHeaders.ACCEPT).append(", ")
        .append(HttpHeaders.CONTENT_TYPE).append(", ")
        .append(HttpHeaders.AUTHORIZATION).append(", ")
        .append(HEADER_IF_MODIFIED_SINCE).append(", ")
        .append(HEADER_CACHE_CONTROL).append(", ")
        .append(HEADER_PRAGMA).append(", ")
        .append(HEADER_CONTENT_DISPOSITION).append(", ");
        return sb.toString();
    }
}

And on client in angular implement http interceptor using following tutorial

https://scotch.io/@kashyapmukkamala/using-http-interceptor-with-angular2

Add all the headers in request in the private getRequestOptionArgs(options?: RequestOptionsArgs) : RequestOptionsArgs {} function