FrankYang0529 commented on code in PR #75542:
URL: https://github.com/apache/airflow/pull/75542#discussion_r4438510665
##########
java-sdk/sdk/src/main/kotlin/org/apache/airflow/sdk/Context.kt:
##########
@@ -92,7 +94,45 @@ data class DagRun(
@JvmField val runAfter: OffsetDateTime?,
@JvmField val runType: DagRunType?,
@JvmField val conf: Map<String, Any?>,
-)
+) {
+ /**
+ * Reads [conf] into a new instance of [type]. For example, [type] can be a
+ * class with one field per conf key.
+ *
+ * ```java
+ * public static class EtlConf {
+ * public String targetTable; // set from the "target_table" key
+ * public int limit = 100; // stays 100 when the conf has no "limit" key
+ * }
+ *
+ * EtlConf etl = context.dagRun.getConf(EtlConf.class);
+ * ```
+ *
+ * Each key goes to the field, setter or record component whose name matches
+ * the key when case and underscores are ignored. If one key matches a name
+ * exactly, that key wins over keys that match the same name only when case
+ * and underscores are ignored. Objects nested in the conf follow the same
+ * rules, including objects in lists and objects that are map values. The
keys
+ * of a map field stay as written.
+ *
+ * Keys that match no field are ignored, because other tasks in the run may
+ * read them. A field with no matching key keeps its default value. The class
+ * needs a no-argument constructor and public fields or setters. A record
also
+ * works. In Kotlin, declare the fields with `@JvmField`, so that a property
+ * such as `isEnabled` keeps its name.
+ *
+ * Annotating a field with [ArgName] has no effect here. Read a key that no
+ * Java name can match, such as `target-table`, from [conf] instead.
+ *
+ * @param type Class to read the conf into.
+ * @throws IllegalArgumentException if a value cannot be converted to the
type
+ * of its field, or if a key holds null for a primitive field. It is also
+ * thrown if two keys match the same field only when case and underscores
+ * are ignored, or if two fields of a class differ only in case or
+ * underscores.
+ */
+ fun <T : Any> getConf(type: Class<T>): T = bindConf(conf, type)
Review Comment:
I will create a follow-up for this as well.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
