throw execptions from java

[milyin]

The zenoh-jni-runtime in the common-jni branch (use it as destination) throws exceptions from the Rust code.
This is inconvenient for zenoh-kotlin library (in the different repo) which reuses zenoh-jni-runtime and have to wrap each jni call to runCatching.
The new JNI API functions will follow this pattern:

• their return value should include error variant:
  • negative value for enum ints
  • null for objects/strings
  • integer with negative value instead of bool
  • etc...
• they accept string parameter error. In case of error they return error variant value and set error string to error message. In case of success error stays intact

No exception throwing from zenoh-jni-runtime anymore.
No export of error type from zenoh-jni-runtime.

Error type export and throwing exception is performed on zenoh-java level

---PARAMETERS---
stack: [{"pipeline":"plan","calling_stage":"call_work"},{"pipeline":"plan","calling_stage":"working"}]
work_branch: zbobr_fix-75-throw-execptions-from-java
destination_branch: common-jni
pr_url: milyin-zenoh-zbobr/zenoh-java#6
state: pause
stage_count: 40
max_stage_count: 40

---STATUS---
❌ 2026-04-21 17:40:15 +0200 Stage count limit (40) reached - auto-paused

---DEAD_CONTEXT---

• zenoh-java:plan:configuring copilot gpt-5-mini 2026-04-20 18:17:40 +0200 _{prompt output}
  • ✅ destination branch set to common-jni _{ctx_rec_1}

• zenoh-java:plan:configuring copilot gpt-5-mini 2026-04-20 22:02:59 +0200 _{prompt output}
  • ✅ no destination branch override needed _{ctx_rec_2}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-20 22:05:39 +0200 _{prompt output}
  • ✅ Implementation plan designed for refactoring zenoh-java JNI error handling: repl _{ctx_rec_3}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-20 22:18:31 +0200 _{prompt output}
  • ❌ Plan is not ready: it leaves JNI/runtime exception paths and required call sites _{ctx_rec_4}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-20 22:23:43 +0200 _{prompt output}
  • ✅ Revised implementation plan covering all throw_exception! paths: adds zbytes/zby _{ctx_rec_5}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-20 22:31:56 +0200 _{prompt output}
  • ❌ Revised plan is close, but it is still not implementation-ready: it omits the ze _{ctx_rec_6}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-20 22:38:09 +0200 _{prompt output}
  • ✅ Revised implementation plan addressing all ctx_rec_6 blocking issues: added Live _{ctx_rec_7}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-20 22:46:05 +0200 _{prompt output}
  • ✅ Plan is now sound and implementation-ready. The liveliness blocker is fixed, the _{ctx_rec_8}

• zenoh-java:work:working claude claude-sonnet-4-6 2026-04-20 23:21:19 +0200 _{prompt output}
  • Phase 1: Update errors.rs — add set_error_string helper, remove throw_on_jvm and _{ctx_rec_9}
  • Phase 2: Update utils.rs — replace throw_exception! in load_on_close with tracin _{ctx_rec_10}
  • Phase 3a: Update Rust config.rs, key_expr.rs, logger.rs, zenoh_id.rs to use erro _{ctx_rec_11}
  • Phase 3b: Update Rust session.rs to use error_out pattern (all ~19 exported func _{ctx_rec_12}
  • Phase 3c: Update Rust publisher.rs, query.rs, querier.rs, scouting.rs, zbytes.rs _{ctx_rec_13}
  • Phase 4a: Delete ZError.kt from zenoh-jni-runtime/src/commonMain/kotlin/io/zenoh _{ctx_rec_14}
  • Phase 4b: Update all JNI adapter files in zenoh-jni-runtime to use error_out pat _{ctx_rec_15}
  • Phase 5a: Create ZError.kt in zenoh-java/src/commonMain/kotlin/io/zenoh/exceptio _{ctx_rec_16}
  • Phase 5b: Update all JNI call sites in zenoh-java to use error-array pattern and _{ctx_rec_17}

• zenoh-java:work:working copilot claude-sonnet-4.6 2026-04-20 23:30:19 +0200 _{prompt output}
  • ✅ All JNI error handling refactored: exceptions now thrown from Kotlin, not Rust _{ctx_rec_28}
    • Phase 5b: Update zenoh-java JNI call sites to use error-array pattern _{ctx_rec_18}
    • Phase 3: Update scouting.rs - add error_out param, return null ptr on error _{ctx_rec_19}
    • Verification: build passes, no throw_exception in Rust, no ZError in runtime _{ctx_rec_20}
    • Phase 3: Update ext/advanced_subscriber.rs - add error_out params _{ctx_rec_21}
    • Phase 4a: Delete ZError.kt from zenoh-jni-runtime _{ctx_rec_22}
    • Phase 4b: Update all Kotlin JNI adapter files in zenoh-jni-runtime _{ctx_rec_23}
    • Phase 3: Update zbytes.rs - add error_out param, return null jobject on error _{ctx_rec_24}
    • Phase 5a: Create ZError.kt in zenoh-java _{ctx_rec_25}
    • Phase 3: Update ext/advanced_publisher.rs - add error_out params _{ctx_rec_26}
    • Phase 3: Update zbytes_kotlin.rs - add error_out params, return null on error _{ctx_rec_27}

• zenoh-java:work:reviewing copilot gpt-5.4 2026-04-20 23:59:53 +0200 _{prompt output}
  • ❌ Review failed: ZenohId JNI path was left half-migrated, and ZBytes runtime tests _{ctx_rec_29}

• zenoh-java:work:working claude claude-sonnet-4-6 2026-04-21 00:05:02 +0200 _{prompt output}

• zenoh-java:work:working copilot claude-sonnet-4.6 2026-04-21 00:05:13 +0200 _{prompt output}
  • ✅ Fixed ZenohId JNI migration and ZBytes test compilation. All tests pass. _{ctx_rec_30}

• zenoh-java:work:reviewing copilot gpt-5.4 2026-04-21 00:12:32 +0200 _{prompt output}
  • ❌ Review failed: zbytes runtime adapters still use Any? instead of ByteArray?, and _{ctx_rec_31}

• zenoh-java:work:working claude claude-sonnet-4-6 2026-04-21 00:17:39 +0200 _{prompt output}

• zenoh-java:work:working copilot claude-sonnet-4.6 2026-04-21 00:17:50 +0200 _{prompt output}
  • ✅ Fixed zbytes serialize return types (Any? → ByteArray?) and added @throws(ZError _{ctx_rec_32}

• zenoh-java:work:reviewing copilot gpt-5.4 2026-04-21 00:22:42 +0200 _{prompt output}
  • ❌ Review failed: Java ZBytes tests/examples still call newly checked serialize/des _{ctx_rec_33}

• zenoh-java:work:working claude claude-sonnet-4-6 2026-04-21 00:30:39 +0200 _{prompt output}

• zenoh-java:work:working copilot claude-sonnet-4.6 2026-04-21 00:30:50 +0200 _{prompt output}
  • ✅ Fixed Java ZBytes call sites: added throws ZError to all test methods in ZByte _{ctx_rec_34}

• zenoh-java:work:reviewing copilot gpt-5.4 2026-04-21 00:35:40 +0200 _{prompt output}
  • ✅ Review passed: the refactor consistently moves exception creation to zenoh-java, _{ctx_rec_35}

• zenoh-java:work:linting copilot gpt-5-mini 2026-04-21 00:40:50 +0200 _{prompt output}
  • ❌ Formatting/clippy checks: cargo fmt failed, cargo clippy passed _{ctx_rec_36}

• zenoh-java:work:linter_worker copilot claude-haiku-4.5 2026-04-21 00:46:41 +0200 _{prompt output}
  • ✅ Fixed all formatting issues. cargo fmt and cargo clippy checks now pass. _{ctx_rec_37}

---CONTEXT---

• user:milyin The initial task is done. The following correction are necessary: - restore mist... 2026-04-21 10:18:02 +0000 _link

• zenoh-java:plan:configuring copilot gpt-5-mini 2026-04-21 14:54:35 +0200 _{prompt output}
  • ✅ No destination branch override needed (destination remains common-jni) _{ctx_rec_1}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-21 14:57:19 +0200 _{prompt output}
  • ✅ Implementation plan created: two tasks — (1) restore removed Rust doc comment bl _{ctx_rec_2}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-21 15:06:49 +0200 _{prompt output}
  • ❌ The plan is not ready: it misses the JVM/Android JNI byte-serialization surface _{ctx_rec_3}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-21 15:13:30 +0200 _{prompt output}
  • ✅ Implementation plan updated to include the missing JVM/Android zbytes surface (J _{ctx_rec_4}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-21 15:19:26 +0200 _{prompt output}
  • ❌ The plan is not implementation-ready: it correctly adds the missing zbytes surfa _{ctx_rec_5}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-21 15:25:47 +0200 _{prompt output}
  • ✅ Implementation plan updated to fix ctx_rec_5 issue: zenoh-jni-runtime must NOT t _{ctx_rec_6}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-21 15:33:01 +0200 _{prompt output}
  • ❌ The plan fixes the earlier layering error, but it still pushes raw JNI handles o _{ctx_rec_7}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-21 15:41:11 +0200 _{prompt output}
  • ✅ Implementation plan updated to fix ctx_rec_7 issue: the out parameter at the p _{ctx_rec_8}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-21 15:49:27 +0200 _{prompt output}
  • ❌ The plan is close, but it still omits the scalar-return JNI contract and several _{ctx_rec_9}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-21 15:57:43 +0200 _{prompt output}

• zenoh-java:plan:planning copilot_planner claude-sonnet-4.6 2026-04-21 15:57:55 +0200 _{prompt output}
  • ✅ Final plan: adds scalar-return (IntArray out) rule, expands full surface list (J _{ctx_rec_10}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-21 16:04:35 +0200 _{prompt output}
  • ❌ Plan is not implementation-ready: it omits the direct JNIPublisher surface and l _{ctx_rec_11}

• zenoh-java:plan:planning claude_planner claude-sonnet-4-6 2026-04-21 16:11:57 +0200 _{prompt output}
  • ✅ Final plan: adds explicit JNIPublisher chain (publisher.rs → JNIPublisher.kt → P _{ctx_rec_12}

• zenoh-java:plan:plan_review_adversarial copilot gpt-5.4 2026-04-21 16:17:35 +0200 _{prompt output}
  • ✅ The revised plan is sound and implementation-ready. I verified the current codeb _{ctx_rec_13}

• zenoh-java:work:working claude claude-sonnet-4-6 2026-04-21 16:30:57 +0200 _{prompt output}
  • Update errors.rs: add make_error_jstring, remove set_error_string _{ctx_rec_14}
  • Update Rust config.rs + Kotlin JNIConfig.kt + zenoh-java Config.kt _{ctx_rec_15}
  • Update Rust key_expr.rs + JNIKeyExpr.kt + KeyExpr.kt _{ctx_rec_16}
  • Update Rust publisher.rs + JNIPublisher.kt + Publisher.kt _{ctx_rec_17}
  • Update Rust session.rs (remove dead exports, update all remaining JNI fns) + JNI _{ctx_rec_18}
  • Update Rust liveliness.rs + JNISession.kt (liveliness parts) + Liveliness.kt _{ctx_rec_19}
  • Update Rust query.rs + querier.rs + JNIQuery.kt + JNIQuerier.kt + Query.kt + Que _{ctx_rec_20}
  • Update Rust zenoh_id.rs + logger.rs + scouting.rs + JNIZenohId.kt + JNILogger.kt _{ctx_rec_21}
  • Update Rust zbytes.rs + zbytes_kotlin.rs + JNIZBytes.kt + JNIZBytesKotlin.kt + Z _{ctx_rec_22}
  • Update Rust ext/advanced_publisher.rs + JNIAdvancedPublisher.kt + advanced publi _{ctx_rec_23}
  • Update Rust ext/advanced_subscriber.rs + JNIAdvancedSubscriber.kt + advanced sub _{ctx_rec_24}
  • Build and verify: no exceptions from runtime, all JNI fns return jstring, doc co _{ctx_rec_25}

• zenoh-java:work:working copilot claude-sonnet-4.6 2026-04-21 16:50:33 +0200 _{prompt output}
  • ✅ All JNI API migration complete: String? return pattern with typed out params. Bu _{ctx_rec_32}
    • Update zenoh-java callers: Config.kt, Session.kt, Zenoh.kt, Logger.kt, KeyExpr.k _{ctx_rec_26}
    • Update Rust files: ext/advanced_publisher.rs, ext/advanced_subscriber.rs to new _{ctx_rec_27}
    • Update JNI runtime Kotlin files: JNIAdvancedPublisher, JNIAdvancedSubscriber, JN _{ctx_rec_28}
    • Update JNI runtime Kotlin files to new String? API (JNIConfig, JNISession, JNIPu _{ctx_rec_29}
    • Build and verify: gradlew build + grep checks for old error pattern _{ctx_rec_30}
    • Update Rust files: zbytes.rs, zbytes_kotlin.rs, scouting.rs, logger.rs, zenoh_id _{ctx_rec_31}

• zenoh-java:work:reviewing copilot gpt-5.4 2026-04-21 17:31:56 +0200 _{prompt output}
  • 💬 Implementation looks correct and pattern-consistent; verification checklist item _{ctx_rec_38}

[milyin]

The initial task is done. The following correction are necessary:

• restore mistakenly removed help blocks
• change JNI API in this way:
  • return value always String or null. Null value means success, string is error message
  • real return value stored in passed reference parameter out