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234 words

javax.persistence.ElementCollection - JPA annotation

javax.persistence
Annotation ElementCollection

Target:
Fields (including property get methods)
Defines a collection of instances of a basic type or embeddable class. Must be specified if the collection is to be mapped by means of a collection table.

Example:

    @Entity public class Person {
       @Id protected String ssn;
       protected String name;
       ...
       @ElementCollection  
       protected Set<String> nickNames = new HashSet();
         ...
    }
Since:
JPA 2.0
FetchType fetch
(Optional) Whether the collection should be lazily loaded or must be eagerly fetched.
(Optional) Whether the collection should be lazily loaded or must be eagerly fetched. The EAGER strategy is a requirement on the persistence provider runtime that the collection elements must be eagerly fetched. The LAZY strategy is a hint to the persistence provider runtime.
Default value:
javax.persistence.FetchType.LAZY
Since:
JPA 2.0
Class targetClass
(Optional) The basic or embeddable class that is the element type of the collection.
(Optional) The basic or embeddable class that is the element type of the collection. This element is optional only if the collection field or property is defined using Java generics, and must be specified otherwise. It defaults to the paramterized type of the collection when defined using generics.
Default value:
void.class
Since:
JPA 2.0
This documentation page is derived (with some adjustments) from the open source JPA 2 RI (EclipseLink)
and is available under the terms of the Eclipse Public License, v. 1.0 and Eclipse Distribution License, v. 1.0.
Object Relational Mapping (ORM) JPA 2 providers include Hibernate, EclipseLink, TopLink, OpenJPA and DataNucleus.
Object DB is not an ORM JPA implementation but an Object Database for Java with built in JPA 2 support.