java-sdk/example/src/resources/dags/java_examples.py

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from __future__ import annotations

from datetime import timedelta

from airflow.sdk import dag, task


@task()
def python_task_1():
    print("python_task_1")
    print("Push Python Task 'python_task_1' XCom:")
    return "value_from_python_task_1"


@task.stub(queue="java")
def extract(): ...


@task.stub(queue="java")
def transform(extracted): ...


@task.stub(queue="java", retries=1, retry_delay=timedelta(seconds=5))
def load(transformed): ...


@task.stub(queue="java")
def concurrent(): ...


# Keyword arguments bind to the public fields of the Java task's TaskInput.
@task.stub(queue="java")
def report(run_label, transformed): ...


@task.stub(queue="java")
def summarize(region_code, transformed): ...


@task.stub(queue="java")
def produce_number(): ...


@task.stub(queue="java")
def widen_to_long(value): ...


@task.stub(queue="java")
def widen_to_double(value): ...


@task.stub(queue="java")
def produce_nothing(): ...


@task.stub(queue="java")
def consume_nullable(value): ...


@task.stub(queue="java")
def produce_fraction(): ...


@task.stub(queue="java")
def consume_float(value): ...


@task.stub(queue="java")
def consume_double_list(values): ...


@task()
def python_task_2(transformed):
    print("python_task_2")
    print("Pull Java Task 'transform' XCom:")
    print(transformed)


@dag(dag_id="java_interface_example")
def java_interface_example():
    extracted = extract()
    python_task_1() >> extracted
    transformed = transform(extracted)
    python_task_2(transformed)
    summarize(region_code="emea", transformed=transformed)


@dag(dag_id="java_annotation_example")
def java_annotation_example():
    extracted = extract()
    python_task_1() >> extracted
    transformed = transform(extracted)
    python_task_2(transformed)
    load(transformed)
    report(run_label="nightly", transformed=transformed)
    concurrent()


@dag(dag_id="java_xcom_casting_example")
def java_xcom_casting_example():
    widen_to_double(widen_to_long(produce_number()))
    consume_nullable(produce_nothing())
    consume_float(produce_fraction())
    consume_double_list([1, 2])


java_interface_example()
java_annotation_example()
java_xcom_casting_example()