de.esprit.netsuite.server.lock

Class ResourceLock

java.lang.Object

de.esprit.common.util.DumpableObject

de.esprit.common.util.TransferableObject

de.esprit.netsuite.server.lock.ResourceLock

All Implemented Interfaces:

Renderable, DeepCloneable, Dumpable, java.io.Serializable, java.lang.Cloneable

public class ResourceLock
extends TransferableObject
implements Renderable

A ResourceLock protects server resources against concurrent client access. There are two types of locks: SHARED and EXCLUSIVE. Many SHARED locks may exist on a resource whereas an EXCLUSIVE lock can only exist once. When a resource is locked exclusively by one client, any other client will receive a ResourceLockedException if he tries to access it exclusively too.

Note that the lock has a dispose timer for protection against too long blocking of the resource. When the dispose timeout exceeds, the resource is released automatically by the server and the client will receive an appropriate warning. The client needs to retrigger the lock periodically as long as he wants to hold it.
Retriggering the lock is automatically enabled when the lock is sent to the client.

Author:

Rainer Buesch

See Also:

LockType, Serialized Form

Constructor Summary

Constructors

Constructor and Description
ResourceLock(ResourceLockManager rscList, ResourceLock lock) This is a copy-constructor to create an EXCLUSIVE version of a SHARED lock
ResourceLock(ResourceLockManager rscList, SessionId sessId, LockType lockType, ResourceType rscType, java.lang.String rscName)
ResourceLock(ResourceLockManager lockMgr, SessionId sessId, LockType lockType, ResourceType rscType, java.lang.String rscName, java.lang.String reason)

Method Summary

Methods

Modifier and Type	Method and Description
void	dispose()
boolean	equals(java.lang.Object obj) Note that it is not sufficient to compare by lockId, instead we must compare four parameters.
long	getFetchTime()
long	getLockDuration()
int	getLockId()
int	getLockTimeout()
LockType	getLockType()
java.lang.String	getReason()
java.awt.Color	getRenderColor()
javax.swing.Icon	getRenderIcon()
java.lang.String	getRenderText()
java.lang.String	getResourceName()
ResourceType	getResourceType()
SessionId	getSessionId()
java.lang.String	getShortInfo()
java.lang.String	getUserName()
int	hashCode()
boolean	isExclusive()
boolean	isShared()
boolean	isStale() Note that a lock is made stale, when the client wants to access it but cannot find it in the ResourceLockList
boolean	isTimedOut() A lock is timed out if it has not been retriggered within a certain time frame.
void	retrigger()
void	setLockTimeout(int seconds)
void	setLockType(LockType type)
void	setReason(java.lang.String reason)
void	setRetriggerEnabled(boolean isRetriggerEnabled)
void	setStale() Note that a lock is made stale, when the client wants to access it but cannot find it in the ResourceLockList
void	startDisposeTimer()
DumpString	toDumpString(DumpString s) Same content as toString, just in a different dump format
ToString	toString(ToString s) This method allows subclasses to add values to the existing ToString of the superclass.

Methods inherited from class de.esprit.common.util.TransferableObject

clone, deepClone

Methods inherited from class de.esprit.common.util.DumpableObject

configureDumpHeadlineLength, configureDumpMaxElementsPrinted, copyDumpStringValues, copyToStringValues, createDumpHeader, toDumpString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ResourceLock

public ResourceLock(ResourceLockManager lockMgr,
            SessionId sessId,
            LockType lockType,
            ResourceType rscType,
            java.lang.String rscName,
            java.lang.String reason)

Parameters:

sessId - the SessionId of the user who requires the lock

lockType - the type of the lock, SHARED or EXCLUSIVE

rscType - the type of a resource

rscName - the unique name of a resource

reason - optional string describing the reason why the lock was fetched

ResourceLock

public ResourceLock(ResourceLockManager rscList,
            SessionId sessId,
            LockType lockType,
            ResourceType rscType,
            java.lang.String rscName)

ResourceLock

public ResourceLock(ResourceLockManager rscList,
            ResourceLock lock)

This is a copy-constructor to create an EXCLUSIVE version of a SHARED lock

Method Detail

setRetriggerEnabled

public void setRetriggerEnabled(boolean isRetriggerEnabled)

startDisposeTimer

public void startDisposeTimer()

getReason

public java.lang.String getReason()

setReason

public void setReason(java.lang.String reason)

getShortInfo

public java.lang.String getShortInfo()

getLockTimeout

public int getLockTimeout()

setLockTimeout

public void setLockTimeout(int seconds)

retrigger

public void retrigger()

getResourceType

public ResourceType getResourceType()

getResourceName

public java.lang.String getResourceName()

getLockId

public int getLockId()

getSessionId

public SessionId getSessionId()

isTimedOut

public boolean isTimedOut()

A lock is timed out if it has not been retriggered within a certain time frame.

isStale

public boolean isStale()

Note that a lock is made stale, when the client wants to access it but cannot find it in the ResourceLockList

setStale

public void setStale()

Note that a lock is made stale, when the client wants to access it but cannot find it in the ResourceLockList

isShared

public boolean isShared()

isExclusive

public boolean isExclusive()

getLockType

public LockType getLockType()

setLockType

public void setLockType(LockType type)

getUserName

public java.lang.String getUserName()

getFetchTime

public long getFetchTime()

getLockDuration

public long getLockDuration()

dispose

public void dispose()

equals

public boolean equals(java.lang.Object obj)

Note that it is not sufficient to compare by lockId, instead we must compare four parameters. This prevents a user from fetching the same lock twice.

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

getRenderIcon

public javax.swing.Icon getRenderIcon()

Specified by:

getRenderIcon in interface Renderable

getRenderText

public java.lang.String getRenderText()

Specified by:

getRenderText in interface Renderable

getRenderColor

public java.awt.Color getRenderColor()

Specified by:

getRenderColor in interface Renderable

toString

public ToString toString(ToString s)

Description copied from interface: Dumpable

This method allows subclasses to add values to the existing ToString of the superclass. Usually subclasses only need to override this method.

Specified by:

toString in interface Dumpable

Overrides:

toString in class DumpableObject

toDumpString

public DumpString toDumpString(DumpString s)

Same content as toString, just in a different dump format

Specified by:

toDumpString in interface Dumpable

Overrides:

toDumpString in class DumpableObject