Spring Operator

**[Sebastien Chatel](https://jira.spring.io/secure/ViewProfile.jspa?name=bugsan)** commented Hello Jonas, I would be interested, but for the moment, i'm working on a more complete use of SAX. Not only for XSLT. After reading this article...

**[Mark Fisher](https://jira.spring.io/secure/ViewProfile.jspa?name=mark.fisher)** commented Moving to M4. Reconsidering this since it would be a breaking change.

**[Artem Bilan](https://jira.spring.io/secure/ViewProfile.jspa?name=abilan)** commented See related StackOverflow question about more info. This is really a matter of the `MetadataStore` and there is no "idempotent service" to avoid readers' confusion.

**[David Turanski](https://jira.spring.io/secure/ViewProfile.jspa?name=dturanski)** commented I tried to implement something like _MessageGroupStoreReaper_ as a _MetadataStoreListener_ in order to track all the keys but not all the implementations (JDBC) are _ListenableMetadataStore_. _MetadataStore_ does...

**[Artem Bilan](https://jira.spring.io/secure/ViewProfile.jspa?name=abilan)** commented The `ListenableMetadataStore` makese sense only in those `MetadataStore` where we really have a callback from the target store. For example Hazelcast. In case of JDBC there is...

**[David Turanski](https://jira.spring.io/secure/ViewProfile.jspa?name=dturanski)** commented `ExpirableMetadataStore` will work. `LAST_UPDATE` is an improvement. By default the value is a timestamp, so I was assuming we can just use that unless we get a...

**[Artem Bilan](https://jira.spring.io/secure/ViewProfile.jspa?name=abilan)** commented Yeah... Agree. The `Set keySet()` would be great addition as well.