There are two sets of properties that may be specified: those that are specific to OpenJPA and those that have been defined by the JPA specification. In some cases, two properties may be equivalent, but have different keys. For example, openjpa.LockTimeout and javax.persistence.lock.timeout are two different keys for the same property.
There are two methods that can be used to retrieve information related to properties:
public Map<String,Object> getProperties(); public Set<String> getSupportedProperties();
getProperties - Provides a list of current
properties. If a property has more than one key, the key
that will be returned is the one that was used when the
property was set. If the property was not explicitly
set, the key defined by the JPA specification will be returned
with the default value.
getSupportedProperties - Returns a set of
supported property keys. This includes keys defined by the JPA
specification as well as keys specific to OpenJPA.
If a property
has more than one key, all possible keys will be returned.
getSupportedProperties method is an OpenJPA
extension to the JPA specification.