javax.persistence

Enum FetchType

java.lang.Object

java.lang.Enum<FetchType>

javax.persistence.FetchType

All Implemented Interfaces:

Serializable, Comparable<FetchType>

public enum FetchType
extends Enum<FetchType>

Defines strategies for fetching data from the database. The EAGER strategy is a requirement on the persistence provider runtime that data must be eagerly fetched. The LAZY strategy is a hint to the persistence provider runtime that data should be fetched lazily when it is first accessed. The implementation is permitted to eagerly fetch data for which the LAZY strategy hint has been specified.

   Example:
   @Basic(fetch=LAZY)
   protected String getName() { return name; }
 

Since:

Java Persistence 1.0

See Also:

Basic, ElementCollection, ManyToMany, OneToMany, ManyToOne, OneToOne

Enum Constant Summary

Enum Constants

Enum Constant and Description
EAGER Defines that data must be eagerly fetched.
LAZY Defines that data can be lazily fetched.

Method Summary

Modifier and Type	Method and Description
static FetchType	valueOf(String name) Returns the enum constant of this type with the specified name.
static FetchType[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

LAZY

public static final FetchType LAZY

Defines that data can be lazily fetched.

EAGER

public static final FetchType EAGER

Defines that data must be eagerly fetched.

Method Detail

values

public static FetchType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (FetchType c : FetchType.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static FetchType valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null