Hi Clay, On Thu, Jul 7, 2016 at 6:55 PM, Clay Ferguson <[email protected]> wrote: > Woosan, > The contentIdentity is basically a "hash" of the data, so it can't be > generated for the first time without using the actual data, so the data I > think has to be read first. But it seems like you could store the hash > somewhere if you wanted to, You could just set a breakpoing on the > 'getContentIdentity' and step into the code and see that it's generating a > hash. Seems like they would have stored this hash so it can be used again, > but i'm not sure if it's stored or not. If it is, stored you could use the > stored value rather than let it get recalculated every time.
If I'm not mistaken, I guess the content id should be stored somewhere by PersistenceManager. DataStore#getRecord(DataIdentifier) is invoked to retrieve binary data if stored in a DataStore. I'm experimenting with VfsDataStore (JCR-3975) and seeing the hash-like identifiers all the time. Should be same as FileDataStore or DbDataStore. In my debugging, it hits org.apache.jackrabbit.core.value.BLOBFileValue#getDataIdentifier() when retrieving a binary value. The method is hard-coded to return null. Maybe I missed something... Thanks for your remarks, Woonsan > > Best regards, > Clay Ferguson > [email protected] > > > On Thu, Jul 7, 2016 at 4:14 PM, Woonsan Ko <[email protected]> wrote: > >> Hi, >> >> I'm trying to retrieve Binary Value Identifier by following [1]. >> The example shows retrieving it when creating a binary value. >> Is it possible to retrieve the identifier when reading binary value >> afterward? >> I tried it like this: >> >> if (value instanceof JackrabbitValue) { >> contentId = ((JackrabbitValue) value).getContentIdentity(); >> } >> >> But, it always returns null. In debugging, it hits >> org.apache.jackrabbit.core.value.BLOBFileValue#getDataIdentifier() in >> my example and the method always returns null. >> >> Is #getContentIdentity() supposed to be used only when creating a >> binary value once initially, or is it kind of shortcoming at the >> moment? >> >> Regards, >> >> Woonsan >> >> [1] https://wiki.apache.org/jackrabbit/DataStore#Retrieve_the_Identifier >>
