Ole, On 3/21/07, Ole Ersoy <[EMAIL PROTECTED]> wrote:
Hey Guys, Just wanted to see if anyone had any thoughts on handling updates to Java beans (Service Data Objects - but basically the same thing) persisted with ADS. With Service Data Objects we create a datagraph that is then disconnected from it's persistence source and we can mutate it. Then later we want to persist the graph. Each object in the graph has a change summary, that stores the fields that were updated.
This change summary is very interesting. I had experimented with something similar which David Jencks did not like too much. Basically the modifier pattern was being used to track modifications to attributes of entities. It was tracking the set of modify add, remove, and replace operations to perform on each attribute.
This makes it possible to only update objects that have been changed, and we only need to update the fields that were changed.
Exactly this is what I was doing in this one admin API I had in triplesec.
However, I think the DirContext will overwrite the entire object during the bind operation, rather than updating specific fields on the object.
Hmmm with heirarchical services in JNDI you should not be using bind(). You should be using the createSubcontext() and modifyAttributes() methods instead. You might want to go through the JNDI tutorial for LDAP just to get a good feel for how to work with non-flat namespaces using JNDI. Namely with LDAP you don't need to rebind the object with a modification to an attribute. This is what the modify operations are for. http://bsd.cs.cofc.edu/Java/Javadocs1.5/api/javax/naming/directory/DirContext.html#modifyAttributes(javax.naming.Name, int, javax.naming.directory.Attributes)
Initially I was thinking that the object's attributes (primitive properties - not references to other objects) would be serialized and made into directory attributes. But I think a LDAP ObjectClass schema that corresponds to the object's class (The class of the object we are persisting) would have to be generated and stored along with the instance. This might lead to performance improvments, if doable...? Thoughts?
Hmmm I think some of your premisses in this question may be due to considering the use of bind() instead of using modifyAttributes() and createSubcontext(). If you use these methods I think there is no further preformance issue to consider. WDYT? Alex
