Default Persistent Types

A default persistent type is a field type that JDO considers to be persistent by default.

In other words, fields declared to be of a default persistent type do not have to be explicitly declared as persistent in the class's JDO metadata.

As defined by the JDO spec (18.4) a type is persistent by default if it is:

• A primitive or a java.lang primitive wrapper type.
• java.lang.String.
• java.util.Date or java.util.Locale.
• java.math.BigDecimal or java.math.BigInteger.
• A persistence-capable class.
• An array of any of the above.
• One of the following java.util classes:
  • ArrayList
  • HashMap
  • HashSet
  • Hashtable
  • LinkedList
  • TreeMap
  • TreeSet
  • Vector
• One of the following java.util interfaces:
  • Collection
  • Set
  • List
  • Map