org.springframework.batch.retry.policy
Class AbstractStatefulRetryPolicy

java.lang.Object
  org.springframework.batch.retry.policy.AbstractStatefulRetryPolicy

All Implemented Interfaces:

RetryPolicy

Direct Known Subclasses:

RecoveryCallbackRetryPolicy

public abstract class AbstractStatefulRetryPolicy
extends Object
implements RetryPolicy

Base class for stateful retry policies: those that operate in the context of a callback that is called once per retry execution (usually to enforce that it is only called once per transaction). Stateful policies need to remember the context for the operation that failed (e.g. the data item that was being processed), and decide based on its history what to do in the current context. For example: the retry operation includes receiving a message, and we need it to roll back and be re-delivered so that we can have another crack at it.

Author:

Dave Syer

See Also:

RetryPolicy.handleRetryExhausted(RetryContext), AbstractStatelessRetryPolicy

Field Summary

protected RetryContextCache

retryContextCache

Constructor Summary

AbstractStatefulRetryPolicy()

Method Summary

Object	handleRetryExhausted(RetryContext context) Return null.
protected boolean	recoverForException(Throwable ex)
void	setRecoverableExceptionClasses(Class[] retryableExceptionClasses) Set the recoverable exceptions.
void	setRetryContextCache(RetryContextCache retryContextCache) Optional setter for the retry context cache.
boolean	shouldRethrow(RetryContext context) For a stateful policy the default is to always rethrow.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.springframework.batch.retry.RetryPolicy

canRetry, close, open, registerThrowable

Field Detail

retryContextCache

protected RetryContextCache retryContextCache

Constructor Detail

AbstractStatefulRetryPolicy

public AbstractStatefulRetryPolicy()

Method Detail

setRetryContextCache

public void setRetryContextCache(RetryContextCache retryContextCache)

Optional setter for the retry context cache. The default value is a MapRetryContextCache.

Parameters:

retryContextCache -

handleRetryExhausted

public Object handleRetryExhausted(RetryContext context)
                            throws ExhaustedRetryException

Return null. Subclasses should provide a recovery path if possible.

Specified by:

handleRetryExhausted in interface RetryPolicy

Parameters:

context - the current retry context.

Returns:

an appropriate value possibly from the callback.

Throws:

ExhaustedRetryException - if there is no recovery path.

See Also:

RetryPolicy.handleRetryExhausted(org.springframework.batch.retry.RetryContext)

shouldRethrow

public boolean shouldRethrow(RetryContext context)

For a stateful policy the default is to always rethrow. This is the cautious approach: we assume that the failed processing may have written data to a transactional resource, so we rethrow and force a rollback. Any recovery path that may be available has to be taken on the next attempt, before any processing has taken place.

Specified by:

shouldRethrow in interface RetryPolicy

Parameters:

context - the current context.

Returns:

true unless the last exception registered was recoverable.

setRecoverableExceptionClasses

public final void setRecoverableExceptionClasses(Class[] retryableExceptionClasses)

Set the recoverable exceptions. Any exception on the list, or subclasses thereof, will be recoverable. If it is encountered in a retry block it will not be rethrown. Others will be rethrown. The recovery action (if any) is left to subclasses - normally they would override handleRetryExhausted(RetryContext).

Parameters:

retryableExceptionClasses - defaults to Exception.

recoverForException

protected boolean recoverForException(Throwable ex)