spring-cloud-netflix: NullPointerException thrown if illegal characters are used in URI

If illegal characters are used in the @FeignClient(“<service_name>”) annotation, then the org.springframework.cloud.netflix.feign.ribbon.LoadBalancerFeignClient will throw a NullPointerException. The execute method uses the following code to create the URI which is then passed down to the cleanUri method:

    URI asUri = URI.create(request.url());
    String clientName = asUri.getHost();
    URI uriWithoutHost = cleanUrl(request.url(), clientName);

static URI cleanUrl(String originalUrl, String host) {
    return URI.create(originalUrl.replaceFirst(host, ""));
}

if the URI has an illegal character, then the “host” is null, which results in a NullPointerException.

If there was a check using a regular expression prior to creating the URI, then the user can be notified that the URL that is being passed in is invalid instead of throwing an NPE.