Does Your Java Proxy Policy Allow a Direct Fallback?
Inspect Java selector candidates when a failed proxy must stop the request rather than permit another route.
A Java proxy selector can return several routing candidates for a URI. When the list contains a proxy followed by Proxy.NO_PROXY, a participating client may try a direct connection after the proxy fails.
The ProxySelector contract defines the candidate list and failure notification. Inspect the result for the exact destination alongside the client's retry and bypass behavior.
If a failed proxy must stop the request, the client's routing policy should not offer a direct alternative. Verify the failure path in the actual runtime: different clients can consume selector results differently.
This policy governs clients using that selector. Another library can create an independent client or socket path, so a selector alone cannot enforce a machine-wide network boundary.