br.shob
Class PhantomReference

java.lang.Object
  |
  +--br.shob.DefaultSharedReference
        |
        +--br.shob.PhantomReference

All Implemented Interfaces:

SharedReference

public final class PhantomReference

extends DefaultSharedReference

A PhantomReference is a special reference that contains an old entry and does not:

• locks on the real object
• listens for updates
• synchronizes on the cached value

It is used primarily by StorageEnvents who need to inform what value has been replaced.

When methods that would require a live reference are called on a PhantomReference, a PhantomCallException is thrown and no work is done. Such methods are BeginTrans, Commit, Rollback, etc.

Version:

$Revision: 1.5 $

Author:

crolmos, dukejeffrie

Created:

September 8, 2002

Field Summary

Fields inherited from interface br.shob.SharedReference

defaultLeaseTime

Constructor Summary

PhantomReference(String globalName, Serializable obj)
Constructor for the PhantomReference object.

PhantomReference(String globalName, SharedSpace shob, Serializable obj)
Constructor for the PhantomReference object

Method Summary

Object	getData() Gets the data attribute of the PhantomReference object
void	srBeginTrans() This method throws a PhantomCallException and should not be called.
void	srCommit() This method throws a PhantomCallException and should not be called.
boolean	srIsUpdated() This method always returns true.
void	srRollback() This method throws a PhantomCallException and should not be called.
void	srUnshare() This method throws a PhantomCallException and should not be called.
void	srValidate() This method throws a PhantomCallException and should not be called.

Methods inherited from class br.shob.DefaultSharedReference

equals, hashCode, srAddStorageListener, srCallMethod, srEquals, srEquals, srGetGlobalName, srRemoveStorageListener, srToString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

PhantomReference

public PhantomReference(String globalName,
                        SharedSpace shob,
                        Serializable obj)

Constructor for the PhantomReference object

Parameters:

globalName - the global name of the object referenced

shob - the shared space who can find the object

obj - the old value of the shared object

PhantomReference

public PhantomReference(String globalName,
                        Serializable obj)

Constructor for the PhantomReference object. Same as calling the constructor and passing a null shared space

Parameters:

globalName - Description of the Parameter

obj - Description of the Parameter

Method Detail

getData

public Object getData()

Gets the data attribute of the PhantomReference object

Overrides:

getData in class DefaultSharedReference

Returns:

The data value

srBeginTrans

public void srBeginTrans()
                  throws ShobException,
                         AlreadyLockedException

This method throws a PhantomCallException and should not be called.

Specified by:

srBeginTrans in interface SharedReference

Overrides:

srBeginTrans in class DefaultSharedReference

Throws:

ShobException - Description of the Exception

AlreadyLockedException - Description of the Exception

srCommit

public void srCommit()
              throws ShobException,
                     NotLockedException

This method throws a PhantomCallException and should not be called.

Specified by:

srCommit in interface SharedReference

Overrides:

srCommit in class DefaultSharedReference

Throws:

ShobException - Description of the Exception

NotLockedException - Description of the Exception

srIsUpdated

public boolean srIsUpdated()

This method always returns true.

Specified by:

srIsUpdated in interface SharedReference

Overrides:

srIsUpdated in class DefaultSharedReference

Returns:

true

srRollback

public void srRollback()
                throws ShobException,
                       NotLockedException

This method throws a PhantomCallException and should not be called.

Specified by:

srRollback in interface SharedReference

Overrides:

srRollback in class DefaultSharedReference

Throws:

ShobException - Description of the Exception

NotLockedException - Description of the Exception

srUnshare

public void srUnshare()
               throws ShobException

This method throws a PhantomCallException and should not be called.

Specified by:

srUnshare in interface SharedReference

Overrides:

srUnshare in class DefaultSharedReference

Throws:

ShobException - Description of the Exception

srValidate

public void srValidate()
                throws ShobException

This method throws a PhantomCallException and should not be called.

Specified by:

srValidate in interface SharedReference

Overrides:

srValidate in class DefaultSharedReference

Throws:

ShobException - Description of the Exception