org.exolab.castor.mapping

Class AccessMode

java.lang.Object

org.exolab.castor.mapping.AccessMode

All Implemented Interfaces:

Serializable, Cloneable, Comparable

public class AccessMode
extends Object
implements Cloneable, Comparable, Serializable

The access mode for a class. This object is used by class descriptors to specify the access mode for a class.

In persistent storage each class is defined as having one of three access modes:

• Read only
• Shared (aka optimistic locking)
• Exclusive (aka pessimistic locking)
• DbLocked (database lock)

Transactions typically access objects based on the specified access mode. A transaction may be requested to access any object as read only or exclusive, but may not access exclusive objects as shared.

Version:

$Revision: 6907 $ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $

Author:

Assaf Arkin, Ralf Joachim

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static AccessMode	DbLocked DbLocked access.
static AccessMode	Exclusive Exclusive access.
static AccessMode	ReadOnly Read only access.
static AccessMode	Shared Shared access.

Method Summary

Methods

Modifier and Type	Method and Description
Object	clone() Clone only returns the one and only instance of this kind.
int	compareTo(AccessMode other)
int	compareTo(Object other) Compares id against id of the specified object.
boolean	equals(Object other) Returns if the specified object and this are one and the same instance.
short	getId()
String	getName()
int	hashCode() Returns the hash code of this object.
protected Object	readResolve() Called during deserialization.
String	toString() Returns the String representation of this kind.
static AccessMode	valueOf(short accessMode)
static AccessMode	valueOf(String accessMode) Returns the access mode from the name.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ReadOnly

public static final AccessMode ReadOnly

Read only access. Objects can be read but are not made persistent and changes to objects are not reflected in persistent storage.

Shared

public static final AccessMode Shared

Shared access. Objects can be read by multiple concurrent transactions. Equivalent to optimistic locking.

Exclusive

public static final AccessMode Exclusive

Exclusive access. Objects can be access by a single transaction at any given time. Equivalent to pessimistic locking.

DbLocked

public static final AccessMode DbLocked

DbLocked access. Objects can be access by a single transaction at any given time, and a lock is acquired in the database.

Method Detail

valueOf

public static AccessMode valueOf(String accessMode)

Returns the access mode from the name. If accessMode is null, return the default access mode (Shared). Otherwise returns the named access mode.

Parameters:

accessMode - The access mode name

Returns:

The access mode

valueOf

public static AccessMode valueOf(short accessMode)

getId

public short getId()

getName

public String getName()

toString

public String toString()

Returns the String representation of this kind.

Overrides:

toString in class Object

Returns:

String representation of this kind.

clone

public Object clone()

Clone only returns the one and only instance of this kind.

Overrides:

clone in class Object

Returns:

The original instance.

equals

public boolean equals(Object other)

Returns if the specified object and this are one and the same instance.

Overrides:

equals in class Object

Parameters:

other - Object to be compared with this instance.

Returns:

true if other equals this else false.

hashCode

public int hashCode()

Returns the hash code of this object.

Overrides:

hashCode in class Object

Returns:

Hash code of this object.

compareTo

public int compareTo(Object other)

Compares id against id of the specified object. So this method is inconsistent with equals(Object).

Specified by:

compareTo in interface Comparable

Parameters:

other - Object to be compared with this instance.

Returns:

A negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

compareTo

public int compareTo(AccessMode other)

readResolve

protected Object readResolve()

Called during deserialization.

Returns:

The existing instance of the enum.
So you can use '==' like 'equals' even if you use a deserialized Enum.