javax.persistence

Annotation Type ElementCollection

@Target(value={METHOD,FIELD})
@Retention(value=RUNTIME)
public @interface ElementCollection

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:

Java Persistence 2.0

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
FetchType	fetch (Optional) Whether the collection should be lazily loaded or must be eagerly fetched.
Class	targetClass (Optional) The basic or embeddable class that is the element type of the collection.

Element Detail

targetClass

public abstract Class targetClass

(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.

Returns:

target class

Default:

void.class

fetch

public abstract FetchType fetch

(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.

Returns:

fetch type

Default:

javax.persistence.FetchType.LAZY