jmri
Class AbstractMemoryManager

java.lang.Object
  jmri.AbstractManager
      jmri.AbstractMemoryManager

All Implemented Interfaces:

PropertyChangeListener, EventListener, Manager, MemoryManager

Direct Known Subclasses:

DefaultMemoryManager

public abstract class AbstractMemoryManager
extends AbstractManager
implements MemoryManager

Abstract partial implementation of a MemoryManager.

Author:

Bob Jacobsen Copyright (C) 2004

Field Summary

Fields inherited from class jmri.AbstractManager

_tsys, _tuser

Constructor Summary

AbstractMemoryManager()

Method Summary

protected abstract Memory	createNewMemory(String systemName, String userName) Internal method to invoke the factory, after all the logic for returning an existing method has been invoked.
Memory	getBySystemName(String key) Locate an instance based on a system name.
Memory	getByUserName(String key) Locate an instance based on a user name.
Memory	getMemory(String name) Locate via user name, then system name if needed.
Memory	newMemory(String sysName, String userName) Return an instance with the specified system and user names.
Memory	provideMemory(String name) Locate via user name, then system name if needed.
char	typeLetter()

Methods inherited from class jmri.AbstractManager

addPropertyChangeListener, deregister, dispose, firePropertyChange, getInstanceBySystemName, getInstanceByUserName, getSystemNameList, makeSystemName, propertyChange, register, removePropertyChangeListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface jmri.MemoryManager

getSystemNameList

Methods inherited from interface jmri.Manager

addPropertyChangeListener, deregister, dispose, makeSystemName, register, removePropertyChangeListener, systemLetter

Constructor Detail

AbstractMemoryManager

public AbstractMemoryManager()

Method Detail

typeLetter

public char typeLetter()

Specified by:

typeLetter in interface Manager

Returns:

The type letter for a specific implementation

provideMemory

public Memory provideMemory(String name)

Description copied from interface: MemoryManager

Locate via user name, then system name if needed. If that fails, create a new Memory. If the name is a valid system name, it will be used for the new Memory. Otherwise, the makeSystemName method will attempt to turn it into a valid system name.

Specified by:

provideMemory in interface MemoryManager

Returns:

Never null under normal circumstances

getMemory

public Memory getMemory(String name)

Description copied from interface: MemoryManager

Locate via user name, then system name if needed. If that fails, return null

Specified by:

getMemory in interface MemoryManager

Returns:

null if no match found

getBySystemName

public Memory getBySystemName(String key)

Description copied from interface: MemoryManager

Locate an instance based on a system name. Returns null if no instance already exists.

Specified by:

getBySystemName in interface MemoryManager

Returns:

requested Memory object or null if none exists

getByUserName

public Memory getByUserName(String key)

Description copied from interface: MemoryManager

Locate an instance based on a user name. Returns null if no instance already exists.

Specified by:

getByUserName in interface MemoryManager

Returns:

requested Memory object or null if none exists

newMemory

public Memory newMemory(String sysName,
                        String userName)

Description copied from interface: MemoryManager

Return an instance with the specified system and user names. Note that two calls with the same arguments will get the same instance; there is only one Memory object representing a given physical Memory and therefore only one with a specific system or user name.

This will always return a valid object reference; a new object will be created if necessary. In that case:

• If a null reference is given for user name, no user name will be associated with the Memory object created; a valid system name must be provided
• If both names are provided, the system name defines the hardware access of the desired Memory, and the user address is associated with it. The system name must be valid.

Note that it is possible to make an inconsistent request if both addresses are provided, but the given values are associated with different objects. This is a problem, and we don't have a good solution except to issue warnings. This will mostly happen if you're creating Memory objects when you should be looking them up.

Specified by:

newMemory in interface MemoryManager

Returns:

requested Memory object (never null)

createNewMemory

protected abstract Memory createNewMemory(String systemName,
                                          String userName)

Internal method to invoke the factory, after all the logic for returning an existing method has been invoked.

Returns:

never null