com.google.appengine.api.memcache
Interface ErrorHandler

All Known Implementing Classes:

LogAndContinueErrorHandler, StrictErrorHandler

public interface ErrorHandler

Handles errors raised by the MemcacheService, registered with MemcacheService.setErrorHandler(ErrorHandler). The default error handler is an instance of LogAndContinueErrorHandler. This will log the underlying error condition, but emulate cache-miss behavior in response rather than surfacing the problem to calling code. A less permissive alternative is StrictErrorHandler, which will instead throw a MemcacheServiceException to expose any errors for application code to resolve.

Method Summary

void	handleDeserializationError(InvalidValueException ivx) Handles deserialization errors.
void	handleServiceError(MemcacheServiceException ex) Handles back-end service errors.

Method Detail

handleDeserializationError

void handleDeserializationError(InvalidValueException ivx)

Handles deserialization errors. This method is called from either of the get methods, if the retrieved value cannot be deserialized. This normally indicates an application upgrade since the cache entry was stored, and should thus be treated as a cache miss, which is the behavior of LogAndContinueErrorHandler (the default).

handleServiceError

void handleServiceError(MemcacheServiceException ex)

Handles back-end service errors. This method is called from any of the MemcacheService methods in the event of a service error. The handler may throw any RuntimeException, or it may simply return for "permissive" error handling, which will generally emulate behavior of a cache miss due to a discarded entry.

Parameters:

ex - the service error exception