Package jakarta.batch.api.partition
Interface PartitionReducer
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- All Known Implementing Classes:
AbstractPartitionReducer
public interface PartitionReducer
PartitionReducer provides unit of work demarcation across partitions. It is not a JTA transaction; no resources are enlisted. Rather, it provides transactional flow semantics to facilitate finalizing merge or compensation logic.
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Nested Class Summary
Nested Classes Modifier and Type Interface Description static class
PartitionReducer.PartitionStatus
An enum used inafterPartitionedStepCompletion(PartitionStatus)
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
afterPartitionedStepCompletion(PartitionReducer.PartitionStatus status)
The afterPartitionedStepCompletion method receives control at the end of a partition processing.void
beforePartitionedStepCompletion()
The beforePartitionedStepCompletion method receives control at the end of partitioned step processing.void
beginPartitionedStep()
The beginPartitionedStep method receives control at the start of partition processing.void
rollbackPartitionedStep()
The rollbackPartitionedStep method receives control if the runtime is rolling back a partitioned step.
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Method Detail
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beginPartitionedStep
void beginPartitionedStep() throws Exception
The beginPartitionedStep method receives control at the start of partition processing. It receives control before the PartitionMapper is invoked and before any partitions are started.- Throws:
Exception
- is thrown if an error occurs.
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beforePartitionedStepCompletion
void beforePartitionedStepCompletion() throws Exception
The beforePartitionedStepCompletion method receives control at the end of partitioned step processing. It receives control after all partitions have completed. It does not receive control if the PartitionReducer is rolling back.- Throws:
Exception
- is thrown if an error occurs.
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rollbackPartitionedStep
void rollbackPartitionedStep() throws Exception
The rollbackPartitionedStep method receives control if the runtime is rolling back a partitioned step. Any partition threads still running are allowed to complete before this method is invoked. This method receives control if any of the following conditions are true:
- One or more partitions end with a Batch Status of STOPPED or FAILED.
- Any of the following partitioned step callbacks
throw an exception:
PartitionMapper
PartitionReducer
PartitionCollector
PartitionAnalyzer - A job with partitioned steps is restarted.
- Throws:
Exception
- is thrown if an error occurs.
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afterPartitionedStepCompletion
void afterPartitionedStepCompletion(PartitionReducer.PartitionStatus status) throws Exception
The afterPartitionedStepCompletion method receives control at the end of a partition processing. It receives a status value that identifies the outcome of the partition processing. The status string value is either "COMMIT" or "ROLLBACK".- Parameters:
status
- specifies the outcome of the partitioned step. Values are "COMMIT" or "ROLLBACK".- Throws:
Exception
- is thrown if an error occurs.
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