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Jason(Zhe-You) Liu
d4013cc2b5
* Java SDK: Pick one of two tasks with a condition A native Java Dag could only run every task it declared: it had no way to let a task's result decide what runs next, so a Dag that loads only when there are rows had to be split in two or fall back to a Python stub. `DagDef.If` and `@Builder.If` declare a task whose boolean names the side that runs; the other is skipped. The deciding task carries `_can_skip_downstream`, so Airflow skips a cleared side again rather than running it, and the SDK writes the `skipmixin_key` XCom before the skip, as Python's SkipMixin does. It skips only the side not taken, so a task after both sides needs a trigger rule such as `none_failed_min_one_success`. `If` is capitalized because `if` is a Java keyword and `@Builder.If` reads the same way. With no task id given, one is derived from the condition class's simple name, so `HasRows.class` becomes `hasRows`. The runtime reaches `SkipDownstreamTasks` through the transport client only, never through the task-facing `Client`, so a task body cannot skip tasks the Dag did not declare it may. * Java SDK: Let a wiring view name a condition's sides in more than one call * Java SDK: Reject a decider class registered as an ordinary task * Java SDK: Name a condition's sides Then and Else * Java SDK: Pin the order a condition skips and records what it skipped * Java SDK: Drop the unused switch in the condition test's decider
3.8 KiB
3.8 KiB
Module sdk
The Apache Airflow Java SDK — author and run Airflow task implementations in JVM languages.
Language SDK compatibility matrix
Which Airflow TaskInstance states and capabilities the Java SDK currently supports. The normative meaning of each dimension is defined in the Language SDK conformance specification.
Min. Airflow version: 3.3 · supervisor schema: 2026-10-30
| Dimension | Tier | Supported | Since | Notes |
|---|---|---|---|---|
| TaskInstance states | ||||
state: success |
MUST | ✓ | 3.3 | |
state: failed |
MUST | ✓ | 3.3 | |
state: up_for_retry |
MUST | ✓ | 3.3 | RetryTask |
state: skipped |
SHOULD | ✗ | – | runtime does not emit TaskState skipped yet |
state: deferred |
MAY | ✗ | – | runtime does not emit DeferTask yet |
state: up_for_reschedule |
MAY | ✗ | – | runtime does not emit RescheduleTask yet |
state: awaiting_input |
MAY | ✗ | – | runtime does not emit AwaitInputTask yet |
state: removed |
MAY | ✓ | 3.3 | |
| Runtime capabilities | ||||
capability: mixed-lang-stub-target |
MUST | ✓ | 3.3 | @task.stub |
capability: taskflow-binding |
MUST | ✗ | – | bind @task.stub literal/XCom args to the native handler |
capability: task-logging |
MUST | ✓ | 3.3 | SLF4J + JPL bridged to the task log |
capability: xcom-read-write |
MUST | ✓ | 3.3 | |
capability: connection-read |
MUST | ✓ | 3.3 | |
capability: variable-read-write |
MUST | ✓ | 3.3 | |
capability: self-contained-bundle |
MUST | ✓ | 3.3 | Airflow metadata embedded in the jar artifact |
capability: retry-policy |
MAY | ✗ | – | no task-facing retry-policy API yet |
capability: task-state-store |
MAY | ✓ | 3.3 | Client.getTaskStateStore() get/set/delete/clear |
capability: asset-state-store |
MAY | ✗ | – | no task-facing state-store API yet |
capability: asset-event-emit |
MAY | ✗ | – | runtime does not emit asset events yet |
capability: asset-event-read |
MAY | ✗ | – | no task-facing asset-event API yet |
| Native-Dag authoring | ||||
capability: native-dag-authoring |
SHOULD | ✓ | 3.4 | |
capability: task-args |
MUST † | ✓ | 3.4 | |
capability: dag-params |
MUST † | ✗ | – | |
capability: taskflow-dependencies |
MUST † | ✓ | 3.4 | |
capability: branching |
SHOULD † | ✓ | 3.4 | DagDef.If / @Builder.If |
capability: dag-test |
SHOULD † | ✗ | – | |
capability: task-group |
MAY † | ✓ | 3.4 | |
capability: dynamic-task-mapping |
MAY † | ✗ | – | |
capability: asset-inlets-outlets |
MAY † | ✗ | – | |
capability: asset-scheduling |
MAY † | ✗ | – | |
capability: object-store |
MAY † | ✗ | – |
Marks: ✓ supported · ✗ not supported · n/a not applicable. A tier marked † applies only when native-dag-authoring is supported.