@Override
    public String resolveHost() {
        String host = super.resolveHost();
        if (host == null) {
            ServletRequest request = resolveServletRequest();
            if (request != null) {
                host = request.getRemoteHost();
            }
        }
        return host;
    }
Default {@code WebSubjectContext} implementation that provides for additional storage and retrieval of
a {@link ServletRequest} and {@link ServletResponse}.

@since 1.0
web/src/main/java/org/apache/shiro/web/subject/support/DefaultWebSubjectContext.java