TIKA-4679: Add HTTP/2 support to tika-server via Jetty http2-server

[nddipiazza]

Summary

Adds HTTP/2 (h2c cleartext) support to tika-server by including the org.eclipse.jetty.http2:http2-server jar on the classpath. When this jar is present, CXF's Jetty transport automatically negotiates HTTP/2 alongside HTTP/1.1 on the existing port (default 9998). Existing HTTP/1.1 clients are completely unaffected.

This implements TIKA-4679. The core dependency change was originally contributed by Lawrence Moorehead (@elemdisc) — see elemdisc/tika PR#1 — and is cherry-picked here with full author credit.

---

Changes

tika-parent/pom.xml

• Added http2-server to the dependency management block alongside the existing http2-hpack, http2-client, http2-common entries (all at ${jetty.http2.version})

tika-server/tika-server-core/pom.xml (Lawrence Moorehead's commit)

• Added org.eclipse.jetty.http2:http2-server runtime dependency (version from parent BOM)

tika-server/tika-server-core/src/test/.../TikaServerIntegrationTest.java (Lawrence Moorehead's commit)

• Added testH2c() unit test that sends a request via HttpClient.Version.HTTP_2 and asserts the response was served over HTTP/2

tika-e2e-tests/tika-server/ (new module)

• New e2e module that starts the actual fat-jar process and validates HTTP/2 (h2c) end-to-end
• Tests are skipped by default; run with -Pe2e
• Wired into tika-e2e-tests/pom.xml

---

How it works

Adding http2-server to the classpath is sufficient for h2c (HTTP/2 cleartext) support. CXF's JettyHTTPServerEngineFactory detects the jar at startup and wires in HTTP2CServerConnectionFactory. No startup code changes are required.

For h2 over TLS (recommended for production), configure TlsConfig in tika-server.json. Java 17's built-in ALPN handles protocol negotiation automatically — no separate ALPN agent is needed.

---

Port management

• Single port (9998 by default) continues to serve both HTTP/1.1 and HTTP/2
• No second port added; Docker EXPOSE 9998 and health-check are unchanged
• The fat-jar grows by ~500 KB from the new jar

---

Shutdown note

HTTP/2 multiplexes multiple requests over a single TCP connection. The current shutdownNow() path does not send a GOAWAY frame before closing. Under moderate load this is acceptable for h2c, but a future improvement could add a drain timeout for graceful HTTP/2 shutdown.

---

Backward compatibility

Purely additive classpath change:

• Does not change the default port
• Does not require TLS (TLS remains opt-in)
• Does not break any existing HTTP/1.1 client
• Does not change the REST API surface

---

Testing Instructions

# Unit test (no external process)
mvn test -pl tika-server/tika-server-core -Dtest=TikaServerIntegrationTest#testH2c

# E2E test (requires fat-jar to be built first)
mvn package -pl tika-server/tika-server-standard -DskipTests
mvn test -pl tika-e2e-tests/tika-server -Pe2e

Manually with curl (after starting the server):

# HTTP/2 cleartext (h2c)
curl --http2-prior-knowledge http://localhost:9998/tika

# HTTP/1.1 — unchanged behavior
curl http://localhost:9998/tika

---

Review Checklist

• http2-server version comes from ${jetty.http2.version} in parent BOM (not hardcoded)
• Existing HTTP/1.1 tests still pass
• TikaServerIntegrationTest#testH2c passes
• E2E module compiles and tests pass with -Pe2e
• No second port introduced

---

Potential Concerns

• h2c vs h2: This PR enables h2c (cleartext). For h2 over TLS an additional jetty-alpn-java-server dependency may be needed depending on the Jetty version and JVM. This can be addressed in a follow-up.
• Reverse proxies: Most reverse proxies (nginx, AWS ALB, GCP LB) do not support h2c — they require h2 over TLS. For internal service-to-service use h2c is fine; for edge deployments, TLS is recommended.
• Fat-jar size: The http2-server jar adds ~500 KB to tika-server-standard. This also increases the apache/tika Docker image slightly.

[tballison]

. For h2 over TLS an additional jetty-alpn-java-server dependency may be needed depending on the Jetty version and JVM. This can be addressed in a follow-up.

I think we're good with Java 17.

[Copilot]

Pull request overview

This PR adds HTTP/2 (h2c cleartext) support to tika-server by adding the org.eclipse.jetty.http2:http2-server jar as a dependency. CXF's Jetty transport automatically detects this jar on the classpath and enables h2c negotiation alongside HTTP/1.1 on the existing port. No application code changes are needed — just the dependency addition.

Changes:

• Added http2-server to the parent BOM dependency management and as a dependency in tika-server-core
• Added a unit test (testH2c) in TikaServerIntegrationTest verifying HTTP/2 negotiation
• Added a new tika-e2e-tests/tika-server module with end-to-end tests that start the actual fat-jar and validate HTTP/2 (h2c) on both status and parse endpoints

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tika-parent/pom.xml	Adds http2-server artifact to the dependency management block using ${jetty.http2.version}
tika-server/tika-server-core/pom.xml	Adds http2-server as a compile dependency (version inherited from parent BOM)
TikaServerIntegrationTest.java	Adds testH2c() unit test using Java's HttpClient to verify HTTP/2 negotiation
tika-e2e-tests/pom.xml	Registers the new tika-server e2e test module
tika-e2e-tests/tika-server/pom.xml	New e2e module POM with surefire skip-by-default and -Pe2e profile activation
TikaServerHttp2Test.java	New e2e test class that starts the fat-jar process and validates h2c on status and parse endpoints

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[nddipiazza]

Addressed both Copilot review comments in commit 30b9ff3:

1. Unused moduleDir variable — removed; repoRoot is now initialized directly from Paths.get("").toAbsolutePath()
2. stopServer() blocking on waitFor() — adopted the safer pattern from IntegrationTestBase.tearDown(): waitFor(5s) → destroyForcibly() → waitFor(30s) to prevent CI hangs

[nddipiazza]

@copilot should i be trying to make the http2 option optional so people aren't forced to have that on classpath?