Session session = repository.login(credentials);

        try

        {

        // here your code

        }

        finally

        {

        session.logout();

        }

      

Use Session.itemExists(String absPath), Node.hasNode(String relPath) or Property.hasProperty(String name). It is also possible to check Node.hasNodes() and Node.hasProprties().

Until it is applicable for a business logic, it can be. But take into account the paths are human readable and let you think in hierarchy. If it is important, a location based approach is preferable.

Session.getNodeByUUID() about 2.5 times faster of Session.getItem(String) and only 25% faster of Node.getNode(String). See the daily test results for such comparisons in the following link as the following: http://tests.exoplatform.org/jcr.html

JCR Observation is a way to listen on persistence changes of a Repository. It provides several options to configure the listener for interesting changes only. To use properly, it is important to understand concept of events filtering for a registered EventListener (8.3.3 Observation Manager). An often confusing part, it is the absPath, it is an associated parent of a location you want to observe events on. For example, it is a parent of child node(s) or this parent property(ies); if isDeep is true, then you will get events of all the subtree of child nodes also. The same actual for uuid and nodeTypeName parameters of the ObservationManager.addEventListener() method.

By default, (if query does not contain any ordering statements) result nodes are sorted by document order.

1. Indexer uses the jcr:encoding property of the nt:resource node (used as the jcr:content child node of nt:file).

2. If no jcr:encoding property is set, the Document Service will use the one configured in the service (defaultEncoding).

3. If nothing is configured a JVM, the default encoding will be used.

No. Any instance of Session or Node (acquired through session) should not be used after logging out anymore. At least, it is highly recommended not to use.