Servlet Filter: How to get all the headers from servletRequest?

Question

Here is how my WebFilter looks like

@WebFilter(\"/rest/*\")
public class AuthTokenValidatorFilter implements Filter {

    @Override
    publi         


        

Answer 1

With Java 8+ you can use a stream to collect request headers:

HttpServletRequest httpRequest = (HttpServletRequest) request;

Map headers = Collections.list(httpRequest.getHeaderNames())
    .stream()
    .collect(Collectors.toMap(h -> h, httpRequest::getHeader));

UPDATED

@Matthias reminded me that headers can have multiple values:

Map>

Map> headersMap = Collections.list(httpRequest.getHeaderNames())    
    .stream()
    .collect(Collectors.toMap(
        Function.identity(), 
        h -> Collections.list(httpRequest.getHeaders(h))
    ));

org.springframework.http.HttpHeaders

HttpHeaders httpHeaders = Collections.list(httpRequest.getHeaderNames())
    .stream()
    .collect(Collectors.toMap(
        Function.identity(),
        h -> Collections.list(httpRequest.getHeaders(h)),
        (oldValue, newValue) -> newValue,
        HttpHeaders::new
    ));

https://gist.github.com/Cepr0/fd5d9459f17da13b29126cf313328fe3