javax.batch.api.chunk

Interface CheckpointAlgorithm

All Known Implementing Classes:

AbstractCheckpointAlgorithm

public interface CheckpointAlgorithm

CheckpointAlgorithm provides a custom checkpoint policy for chunk steps.

Method Summary

Modifier and Type	Method and Description
void	beginCheckpoint() The beginCheckpoint method is invoked before the next checkpoint interval begins (before the next chunk transaction begins).
int	checkpointTimeout() The checkpointTimeout is invoked at the beginning of a new checkpoint interval for the purpose of establishing the checkpoint timeout.
void	endCheckpoint() The endCheckpoint method is invoked after the last checkpoint is taken (after the chunk transaction is committed).
boolean	isReadyToCheckpoint() The isReadyToCheckpoint method is invoked by the batch runtime after each item is processed to determine if now is the time to checkpoint the current chunk.

Method Detail

checkpointTimeout

int checkpointTimeout()
               throws Exception

The checkpointTimeout is invoked at the beginning of a new checkpoint interval for the purpose of establishing the checkpoint timeout. It is invoked before the next chunk transaction begins. This method returns an integer value, which is the timeout value (expressed in seconds) which will be used for the next chunk transaction. This method is useful to automate the setting of the checkpoint timeout based on factors known outside the job definition. A value of '0' signifies no maximum established by this CheckpointAlgorithm, i.e. the maximum permissible timeout allowed by the runtime environment.

Returns:

the timeout interval (expressed in seconds) to use for the next checkpoint interval

Throws:

Exception - thrown for any errors.

beginCheckpoint

void beginCheckpoint()
              throws Exception

The beginCheckpoint method is invoked before the next checkpoint interval begins (before the next chunk transaction begins).

Throws:

Exception - thrown for any errors.

isReadyToCheckpoint

boolean isReadyToCheckpoint()
                     throws Exception

The isReadyToCheckpoint method is invoked by the batch runtime after each item is processed to determine if now is the time to checkpoint the current chunk.

Returns:

boolean indicating whether or not to checkpoint now.

Throws:

Exception - thrown for any errors.

endCheckpoint

void endCheckpoint()
            throws Exception

The endCheckpoint method is invoked after the last checkpoint is taken (after the chunk transaction is committed).

Throws:

Exception - thrown for any errors.