Session: How to Get Entity Change-Vector
The change-vector reflects the cluster wide point in time where something happened. It includes the unique database ID, node identifier, and the Etag of the document in the specific node.
When a document is downloaded from the server, it contains various metadata information e.g. ID or current change-vector. Current change-vector is stored within the metadata in session and is available for each entity using the getChangeVectorFor
method from the advanced
session operations.
Syntax
<T> String getChangeVectorFor(T instance)
Parameters |
|
|
instance |
T |
Instance of an entity for which an Etag will be returned. |
Return Value |
|
String |
Returns the current change-vector for an entity. Throws an exception if the instance is not tracked by the session. |
Example
Employee employee = session.load(Employee.class, "employees/1-A");
String changeVector = session.advanced().getChangeVectorFor(employee);