wt.locks
Class LockHelper

java.lang.Object
  wt.locks.LockHelper

All Implemented Interfaces:

Externalizable, Serializable

public final class LockHelper
extends Object
implements Externalizable

Provides an abstraction as the API (Application Programming Interface) to the lock services. This API includes only class methods and must be used accordingly. These methods can be categorized as local and remote invocations. The local methods are getters of information, typically from cookies, that are held in the client. The remote methods serve as wrappers to services that promote server-side functionality to clients.

Supported API: true

Extendable: false

See Also:

Lockable, LockService, Serialized Form

Field Summary

static boolean	LOCKED An indication, passed to getSearchCondition, to build a search condition to find all locked objects.
static LockService	service Supported API: true
static boolean	UNLOCKED An indication, passed to getSearchCondition, to build a search condition to find all unlocked objects.

Method Summary

static Lockable	assignLock(Lockable object, WTPrincipalReference locker, String note) Assigns a lock on the given lockable object by the given principal.
static Lockable	assignLock(Lockable object, WTPrincipalReference locker, String note, Timestamp date) Assigns a lock on the given lockable object to the given principal, note and date.
static WTCollection	assignLock(WTCollection lockables, WTPrincipalReference locker, String note) Assigns a lock on the given lockable objects by the given principal.
static Timestamp	getDate(Lockable object) Gets the time when the object was locked.
static WTPrincipal	getLocker(Lockable object) Gets the principal who placed the lock.
static WTPrincipalReference	getLockerReference(Lockable object) Gets the principal who placed the lock.
static String	getNote(Lockable object) Gets the reason why the object was locked.
static SearchCondition	getSearchCondition(Class target, boolean state) Gets a SearchCondition to be appended to a query of all the objects that are either locked or unlocked.
static SearchCondition	getSearchCondition(Class target, WTPrincipal principal, boolean state) Gets a SearchCondition to be appended to a query of all the objects that are either locked or unlocked for a given principal.
static SearchCondition	getSearchCondition(Class target, WTPrincipalReference principal, boolean state) Gets a SearchCondition to be appended to a query of all the objects that are either locked or unlocked for a given principal.
static boolean	isLocked(Lockable object) Tests if the given object has been locked.
static Lockable	releaseLock(Lockable object) Releases the lock that has been placed on the given lockable object.
static WTCollection	releaseLock(WTCollection objectSet) Releases the lock that has been placed on the given collection of lockable objects.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOCKED

public static final boolean LOCKED

An indication, passed to getSearchCondition, to build a search condition to find all locked objects. If it is used in conjunction with a principal then the search condition is built to find all objects locked by the principal.

Supported API: true

See Also:

Constant Field Values

UNLOCKED

public static final boolean UNLOCKED

An indication, passed to getSearchCondition, to build a search condition to find all unlocked objects. If it is used in conjunction with a principal then the search condition is built to find all objects not locked by the principal.

Supported API: true

See Also:

Constant Field Values

service

public static final LockService service

Supported API: true

Method Detail

assignLock

public static Lockable assignLock(Lockable object,
                                  WTPrincipalReference locker,
                                  String note)
                           throws WTException,
                                  LockException,
                                  WTPropertyVetoException

Assigns a lock on the given lockable object by the given principal. This method is synchronous to allow for concurrent processing on shared lockable objects between threads.

Supported API: true

Parameters:

object -

locker -

note -

Returns:

Lockable

Throws:

WTException

LockException

WTPropertyVetoException

releaseLock

public static Lockable releaseLock(Lockable object)
                            throws WTException,
                                   LockException,
                                   WTPropertyVetoException

Releases the lock that has been placed on the given lockable object. This method is synchronous to allow for concurrent processing on shared lockable objects between threads.

Supported API: true

Parameters:

object -

Returns:

Lockable

Throws:

WTException

LockException

WTPropertyVetoException

isLocked

public static boolean isLocked(Lockable object)
                        throws LockException

Tests if the given object has been locked.

Supported API: true

Parameters:

object -

Returns:

boolean

Throws:

LockException

getDate

public static Timestamp getDate(Lockable object)
                         throws LockException

Gets the time when the object was locked.

Supported API: true

Parameters:

object -

Returns:

Timestamp

Throws:

LockException

getNote

public static String getNote(Lockable object)
                      throws LockException

Gets the reason why the object was locked.

Supported API: true

Parameters:

object -

Returns:

String

Throws:

LockException

getLocker

public static WTPrincipal getLocker(Lockable object)
                             throws LockException

Gets the principal who placed the lock. If this is done directly from an existing object, the lock of which has been set, then the principal exists within the lock and can be immediately returned. Otherwise, the object and its lock was initialized via a query and the principal does not exist within the lock. So the principal must be fetched from the database given the OID for the principal stored within the lock.

Supported API: true

Parameters:

object -

Returns:

WTPrincipal

Throws:

LockException

getLockerReference

public static WTPrincipalReference getLockerReference(Lockable object)
                                               throws LockException

Gets the principal who placed the lock. If this is done directly from an existing object, the lock of which has been set, then the principal exists within the lock and can be immediately returned. Otherwise, the object and its lock was initialized via a query and the principal does not exist within the lock. So the principal must be fetched from the database given the OID for the principal stored within the lock.

Supported API: true

Parameters:

object -

Returns:

WTPrincipalReference

Throws:

LockException

getSearchCondition

public static SearchCondition getSearchCondition(Class target,
                                                 boolean state)
                                          throws LockException,
                                                 QueryException

Gets a SearchCondition to be appended to a query of all the objects that are either locked or unlocked. This search condition can be used as a way to find out what objects are (un)locked regardless of who is the principal.

Supported API: true

Parameters:

target -

state -

Returns:

SearchCondition

Throws:

LockException

QueryException

getSearchCondition

public static SearchCondition getSearchCondition(Class target,
                                                 WTPrincipal principal,
                                                 boolean state)
                                          throws WTException,
                                                 LockException,
                                                 QueryException

Gets a SearchCondition to be appended to a query of all the objects that are either locked or unlocked for a given principal. This search condition can be used as a way to find out what objects are (un)locked based on a particular principal.

Supported API: true

Parameters:

target -

principal -

state -

Returns:

SearchCondition

Throws:

WTException

LockException

QueryException

getSearchCondition

public static SearchCondition getSearchCondition(Class target,
                                                 WTPrincipalReference principal,
                                                 boolean state)
                                          throws WTException,
                                                 LockException,
                                                 QueryException

Gets a SearchCondition to be appended to a query of all the objects that are either locked or unlocked for a given principal. This search condition can be used as a way to find out what objects are (un)locked based on a particular principal.

Supported API: true

Parameters:

target -

principal -

state -

Returns:

SearchCondition

Throws:

WTException

LockException

QueryException

releaseLock

public static WTCollection releaseLock(WTCollection objectSet)
                                throws WTException,
                                       LockException,
                                       WTPropertyVetoException

Releases the lock that has been placed on the given collection of lockable objects.

Supported API: true

Parameters:

objectSet -

Returns:

WTCollection

Throws:

WTException

LockException

WTPropertyVetoException

See Also:

releaseLock(Lockable object)

assignLock

public static WTCollection assignLock(WTCollection lockables,
                                      WTPrincipalReference locker,
                                      String note)
                               throws LockException

Assigns a lock on the given lockable objects by the given principal. This method is synchronous to allow for concurrent processing on shared lockable objects between threads.

Supported API: true

Parameters:

lockables -

locker -

note -

Returns:

WTCollection

Throws:

LockException

assignLock

public static Lockable assignLock(Lockable object,
                                  WTPrincipalReference locker,
                                  String note,
                                  Timestamp date)
                           throws WTException,
                                  LockException,
                                  WTPropertyVetoException

Assigns a lock on the given lockable object to the given principal, note and date. If the principal is null the current session principal is used. If the date is null the current system time down to milliseconds is used. This method is only intended to be used when loading information into the lockable object before it is persisted. Otherwise, if it is already persistent an exception will occur. This method is synchronous to allow for concurrent processing on shared lockable objects between threads.

Supported API: true

Parameters:

object -

locker -

note -

date -

Returns:

Lockable

Throws:

WTException

LockException

WTPropertyVetoException