Port Floxis: New Adapter

[floxis-admin]

🔧 Type of changes

• new bid adapter

✨ Whats the context?

This PR ports the Floxis bid adapter from PBS-Go to PBS-Java. Floxis is an ad exchange; the adapter sends standard OpenRTB 2.x server-to-server bid requests to the Floxis exchange so PBS publishers can access Floxis demand. It is the Java counterpart of the in-review Go adapter prebid/prebid-server#4811.

Scope:

• Media types: banner, video, native, audio (declared for both app and site).
• OpenRTB 2.6; GPP supported. The incoming bid request body is forwarded unchanged.
• Cookie sync: redirect type.
• modifying-vast-xml-allowed: false.

🧠 Rationale behind the change

Bidder params (imp[].ext.prebid.bidder.floxis):

• seat (string, required, minLength 1) — the Floxis seat the publisher buys through; appended url-escaped to the endpoint as ?seat=.
• region (string, optional, default us-e) — the regional RTB host, used as a subdomain label. Validated as a DNS label by the params JSON schema.
• partner (string, optional, default floxis) — white-label partner, used as an additional subdomain label. Validated as a DNS label by the params JSON schema.

Endpoint routing: the fixed parent domain (.floxis.tech) is pinned in the adapter's endpoint config; only the {{Host}} subdomain is filled from the request. The subdomain is region (e.g. us-e.floxis.tech), or partner-region for a named white-label partner (e.g. acme-us-e.floxis.tech); the default floxis partner adds no prefix. region/partner are constrained to DNS labels by the params schema and url-encoded before interpolation, so the host can never be derived from a request-supplied hostname — satisfying the "no fully dynamic hostnames" requirement. seat/region/partner are read from the first imp; a multi-imp request that mixes seats/regions/partners is rejected as bad input (one request routes to one host). The request body is forwarded unchanged (no caller-owned object is mutated).

Bid type resolution treats bid.mtype (OpenRTB 2.6) as authoritative (1/2/3/4 → banner/video/audio/native). When mtype is absent, a single-format imp resolves to that media type; an imp without exactly one format cannot be disambiguated and surfaces a badServerResponse, while other bids in the response continue to be processed.

gvlVendorID is set to 1609 — Floxis (legal entity Ad Tech Company OÜ) is registered as an IAB TCF vendor with GVL ID 1609, so EU/TCF consent is enforced against that vendor ID.

🔎 New Bid Adapter Checklist

• verify email contact works
• NO fully dynamic hostnames
• geographic host parameters are NOT required
• direct use of HTTP is prohibited - implement an existing Bidder interface that will do all the job
• if the ORTB is just forwarded to the endpoint, use the generic adapter - the adapter is not a plain forward: it performs region/partner-based host routing, url-escaped seat injection, and mtype/single-format bid-type resolution, so a dedicated adapter is warranted
• cover an adapter configuration with an integration test

🧪 Test plan

• FloxisBidderTest — unit tests covering region/partner host resolution (default, explicit region, partner-prefixed host), url-encoding of the seat and the host parts, request-forwarded-unchanged, the per-imp consistency check, and the full getMediaTypeForBid matrix (mtype-authoritative for all four types, unsupported mtype, single-format fallback for all four, the non-single-format error, imp-not-found), plus per-bid error accumulation. JaCoCo reports ~100% line coverage on FloxisBidder.
• FloxisTest integration test — exercises the full auction path against WireMock and validates the adapter configuration is reachable.
• mvn test (unit + IT) and mvn checkstyle:check pass locally.

🏎 Quality check

• Are your changes following our code style guidelines?
• Are there any breaking changes in your code? — No.
• Does your test coverage exceed 90%? — Yes (~100% line on the bidder).
• Are there any erroneous console logs, debuggers or leftover code in your changes? — No.

---

Companion Go adapter: prebid/prebid-server#4811. The corresponding prebid.github.io documentation PR: prebid/prebid.github.io#6596 (approved).

Please add the do not port label per the porting guide (I do not have label permissions on this repo).

[floxis-admin]

Thanks for the thorough review @CTMBNara — all of it is addressed in 21d1900: dropped the redundant empty-imp check, the in-code DNS regex (floxis.json already covers it) and the custom isBlank helper; reworked makeHttpRequests into the parse-first/validate-the-rest shape; extracted extractBids and countFormats; url-encoded the host parts; and cleared out the comments. Also synced the PR description with the final code. Ready for another look whenever you have a moment.

[floxis-admin]

Hi @CTMBNara — thanks for the thorough review. I've applied all of the feedback in the latest commit:

• dropped the redundant guards and comments
• reworked makeHttpRequests into the parse-first-then-validate shape you suggested
• switched to StringUtils.isBlank
• URL-encode the dynamic host parts
• extracted extractBids
• added a countFormats helper that throws unless exactly one format is present

I've replied inline on each thread. Whenever you have a moment, could you take another pass? Happy to adjust anything further — thanks again for your time.

[floxis-admin]

Documentation PR (per the add-new-bidder checklist): prebid/prebid.github.io#6596 — already approved by @muuki88; it sets pbs: true, gvl_id: 1609 and documents the PBS endpoints/params.

@CTMBNara re-review is requested since 21d1900 addressed all of your feedback — and one note: the CI workflows on that commit (Java CI / functional tests / CodeQL / Trivy) are awaiting first-time-contributor approval, so they haven't run yet. Could you approve the runs when you pick this back up?