Why CIDR Exclusions Do Not Translate Directly to Java nonProxyHosts
Use Java's pipe-separated hostname-pattern language rather than treat a copied subnet entry as an address-routing rule.
http.nonProxyHosts accepts documented host patterns separated by pipes. A copied 169.254/16 value does not make it classify that subnet.
An IDE importing operating-system exceptions can expose this mismatch to Java/Gradle. Removing the whole list may hide a warning while discarding intended direct routes.
Translate the requirement, not just punctuation: explicit internal hostnames can express a small named set. Address-based policy needs a supported mechanism rather than an assumed CIDR extension.
Also distinguish a literal address in the URL from resolving a hostname and checking the result. This matcher is not automatically a routing table or DNS-subnet classifier. Keep the consumer and its syntax with the exception policy.