| java.lang.Object
 org.jasig.portal.services.EntityLockService
| EntityLockService | | public class EntityLockService (Code) | | This is a bootstrap class and facade for the IEntityLockService implementation.
It presents a simple api for acquiring lock objects, IEntityLocks,
that can be used to control concurrent access to portal entities in a
multi-server environment. (See org.jasig.portal.concurrency.IEntityLockService
for a fuller description.)
Currently supported lock types are IEntityLockService.READ_LOCK and
IEntityLockService.WRITE_LOCK.
If I want to lock an entity for update, I ask the service for a write lock:
Class type = anEntity.getClass(); // maybe hard-coded(?)
String key = anEntity.getKey();
EntityIdentifier ei = new EntityIdentifier(key, type);
String owner = getThePortalUserId();
IEntityLock lock = EntityLockService.instance().newWriteLock(ei, owner);
Or maybe:
IEntityLock lock = EntityLockService.instance().newWriteLock(ei, owner, duration);
If there are no conflicting locks on the entity, the service returns the
requested lock. If I acquire the lock, I know that no other client will be
able to get a conflicting lock, and from then on, I communicate with the
service via the lock:
lock.convert(int newType); // See IEntityLockService for types.
lock.isValid();
lock.release();
lock.renew();
A READ lock guarantees shared access; other clients can get READ locks
but not WRITE locks. A WRITE lock guarantees exclusive access; no other
clients can get either READ or WRITE locks on the entity.
author:
Dan Ellentuck
version:
$Revision: 35551 $ |
| Method Summary | |
| public static synchronized EntityLockService | instance()
| | public IEntityLock | newReadLock(Class entityType, String entityKey, String owner)
Returns a read lock for the entity type, entity key and owner. | | public IEntityLock | newReadLock(Class entityType, String entityKey, String owner, int duration)
Returns a read lock for the entity type, entity key and owner. | | public IEntityLock | newReadLock(EntityIdentifier entityID, String owner)
Returns a read lock for the IBasicEntity and owner. | | public IEntityLock | newReadLock(EntityIdentifier entityID, String owner, int durationSecs)
Returns a read lock for the IBasicEntity, owner and duration. | | public IEntityLock | newWriteLock(Class entityType, String entityKey, String owner)
Returns a write lock for the entity type, entity key and owner. | | public IEntityLock | newWriteLock(Class entityType, String entityKey, String owner, int durationSecs)
Returns a write lock for the entity type, entity key and owner. | | public IEntityLock | newWriteLock(EntityIdentifier entityID, String owner)
Returns a write lock for the IBasicEntity and owner. | | public IEntityLock | newWriteLock(EntityIdentifier entityID, String owner, int durationSecs)
Returns a write lock for the IBasicEntity, owner and duration. |
| newReadLock | | public IEntityLock newReadLock(Class entityType, String entityKey, String owner) throws LockingException(Code) | | Returns a read lock for the entity type, entity key and owner.
org.jasig.portal.concurrency.locking.IEntityLock
Parameters:
entityType - Class
Parameters:
entityKey - String
Parameters:
owner - String
exception:
LockingException - |
| newReadLock | | public IEntityLock newReadLock(Class entityType, String entityKey, String owner, int duration) throws LockingException(Code) | | Returns a read lock for the entity type, entity key and owner.
org.jasig.portal.concurrency.locking.IEntityLock
Parameters:
entityType - Class
Parameters:
entityKey - String
Parameters:
owner - String
Parameters:
duration - int (in seconds)
exception:
LockingException - |
| newReadLock | | public IEntityLock newReadLock(EntityIdentifier entityID, String owner, int durationSecs) throws LockingException(Code) | | Returns a read lock for the IBasicEntity, owner and duration.
org.jasig.portal.concurrency.locking.IEntityLock
Parameters:
entityID - EntityIdentifier
Parameters:
owner - String
Parameters:
durationSecs - int
exception:
LockingException - |
| newWriteLock | | public IEntityLock newWriteLock(Class entityType, String entityKey, String owner) throws LockingException(Code) | | Returns a write lock for the entity type, entity key and owner.
org.jasig.portal.concurrency.locking.IEntityLock
Parameters:
entityType - Class
Parameters:
entityKey - String
Parameters:
owner - String
exception:
LockingException - |
| newWriteLock | | public IEntityLock newWriteLock(Class entityType, String entityKey, String owner, int durationSecs) throws LockingException(Code) | | Returns a write lock for the entity type, entity key and owner.
org.jasig.portal.concurrency.locking.IEntityLock
Parameters:
entityType - Class
Parameters:
entityKey - String
Parameters:
owner - String
Parameters:
durationSecs - int
exception:
LockingException - |
| newWriteLock | | public IEntityLock newWriteLock(EntityIdentifier entityID, String owner, int durationSecs) throws LockingException(Code) | | Returns a write lock for the IBasicEntity, owner and duration.
org.jasig.portal.concurrency.locking.IEntityLock
Parameters:
entityID - EntityIdentifier
Parameters:
owner - String
Parameters:
durationSecs - int
exception:
LockingException - |
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