org.exolab.castor.mapping
Class AccessMode

java.lang.Object
  org.exolab.castor.mapping.AccessMode

public class AccessMode

extends java.lang.Object

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: 1.1.1.1 $ $Date: 2003/03/03 07:08:26 $

Author:

Assaf Arkin

Field Summary

static AccessMode	DbLocked DbLocked access.
static AccessMode	Exclusive Exclusive access.
static AccessMode	ReadOnly Read only access.
static AccessMode	Shared Shared access.

Method Summary

static AccessMode	getAccessMode(java.lang.String accessMode) Returns the access mode from the name.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, 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

getAccessMode

public static AccessMode getAccessMode(java.lang.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

toString

public java.lang.String toString()