JDO vendors may supply public constructors for their PersistenceManagerFactory implementations, but the recommended method of obtaining a PersistenceManagerFactory is through the Java Connector Architecture (JCA) in a managed environment, or through the JDOHelper's getPersistenceManagerFactory methods in an unmanaged environment, as described in Section 6.3, “PersistenceManagerFactory Construction”. PersistenceManagerFactories obtained through these means are immutable; any attempt to change their property settings will result in a JDOUserException. This is because the returned factory may come from a pool, and might be shared by other application components.

JDO requires that concrete PersistenceManagerFactory classes implement the Serializable interface. This allows you to create and configure a PersistenceManagerFactory, then serialize it to a file or store it in a Java Naming and Directory Interface (JNDI) tree for later retrieval and use.