HttpServletRequestのヘッダをMapに変換

import javax.servlet.http.HttpServletRequest;
import java.util.Collections;
import java.util.HashMap
import java.util.Map;
import java.util.stream.Collectors;

public class Utils {

    public static Map<String, String> getHeaderMap(HttpServletRequest request) {

        return  new HashMap<String, String>() {{
            Collections.list(request.getHeaderNames())
            	.stream()
                .forEach(key -> {
                	put(key, request.getHeader(key));
            });
    	}};
    }

}