org.wandora.modules.topicmap

Class SimpleTopicMapManager

java.lang.Object

org.wandora.modules.AbstractModule

org.wandora.modules.topicmap.SimpleTopicMapManager

All Implemented Interfaces:

Module, TopicMapManager

public class SimpleTopicMapManager
extends AbstractModule
implements TopicMapManager

Basic implementation of the topic map manager. Simply loads the topic map from a file and gives direct access to that. The file can either be an xtm file or a Wandora project file. Optionally, can be set to save the topic map at regular intervals, or alternatively to reload the topic map file at regular intervals.

The topic map file is set with the initialisation parameter topicMapFile. Alternatively you can also set the topic map directly by giving a topic map object in the parameter topicMap. In this case the auto save and reload features cannot be used.

Auto saving is set with the autoSave initialisation parameter. The value is the saving interval in minutes. Use 0 to disable auto saving, which is the default. Setting this parameter to "true" enables auto saving every 10 minutes. Note that the topic map will be written to disk whether or not actual changes in it have occurred.

Automatic file reloading can be set with autoRefresh parameter, set it to true to enable automatic reloading. The topic map is reloaded whenever its timestamp changes, this is checked roughly once every minute.

You should not use both auto saving and reloading at the same time. Or in general, you should not use auto saving at all if you intend to modify the file while this module is running. This can very easily lead to a situation where this module overwrites your changes.

Author:

olli

Nested Class Summary

Nested classes/interfaces inherited from interface org.wandora.modules.topicmap.TopicMapManager

TopicMapManager.TopicMapManagerListener

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	autoRefresh
protected int	autoSave
protected java.lang.String	autoSaveFile
protected java.lang.Thread	autoThread
protected boolean	autoThreadRunning
protected java.lang.Object	autoThreadWait
protected long	lastLoad
protected long	lastSave
protected ListenerList<TopicMapManager.TopicMapManagerListener>	managerListeners
protected TopicMap	tm
protected java.util.concurrent.locks.ReadWriteLock	tmLock
protected java.lang.String	topicMapFile

Fields inherited from class org.wandora.modules.AbstractModule

autoStart, isInitialized, isRunning, logging, loggingModule, moduleManager

Constructor Summary

Constructors

Constructor and Description
SimpleTopicMapManager()

Method Summary

Modifier and Type	Method and Description
void	addTopicMapManagerListener(TopicMapManager.TopicMapManagerListener listener) Adds a topic map listener that will be notified when the managed topic map is replaced with another topic map.
protected void	autoThreadRun()
protected void	fireTopicMapChanged(TopicMap old, TopicMap neu)
java.util.Collection<Module>	getDependencies(ModuleManager manager) Returns all the modules this module depends on.
TopicMap	getTopicMap() Returns the topic map managed by this topic map manager.
void	init(ModuleManager manager, java.util.HashMap<java.lang.String,java.lang.Object> settings) Initialises the module.
boolean	lockRead() Locks the topic map for reading.
boolean	lockWrite() Locks the topic map for writing.
void	reloadTopicMap()
void	removeTopicMapManagerListener(TopicMapManager.TopicMapManagerListener listener) Removes a topic map listener.
void	saveTopicMap()
void	start(ModuleManager manager) Starts the module.
protected void	startAutoThread()
void	stop(ModuleManager manager) Stops the module.
void	unlockRead() Releases a previously acquired read lock.
void	unlockWrite() Releases a previously acquired write lock.

Methods inherited from class org.wandora.modules.AbstractModule

isInitialized, isRunning, requireLogging, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.wandora.modules.Module

isInitialized, isRunning

Field Detail

managerListeners

protected final ListenerList<TopicMapManager.TopicMapManagerListener> managerListeners

tmLock

protected java.util.concurrent.locks.ReadWriteLock tmLock

tm

protected TopicMap tm

topicMapFile

protected java.lang.String topicMapFile

autoSaveFile

protected java.lang.String autoSaveFile

autoRefresh

protected boolean autoRefresh

autoSave

protected int autoSave

lastSave

protected long lastSave

lastLoad

protected long lastLoad

autoThreadRunning

protected boolean autoThreadRunning

autoThread

protected java.lang.Thread autoThread

autoThreadWait

protected final java.lang.Object autoThreadWait

Constructor Detail

SimpleTopicMapManager

public SimpleTopicMapManager()

Method Detail

getDependencies

public java.util.Collection<Module> getDependencies(ModuleManager manager)
                                             throws ModuleException

Description copied from interface: Module

Returns all the modules this module depends on. This method will be called after init and the dependencies are allowed to depend on the parameters passed to init. The modules that this module depends on must be returned as a collection. In addition, if any required module is not present, a MissingDependencyException should be thrown. Typically you will use the requireModule and optionalModule methods of the manager to make sure that the modules exist and add them to the collection. requireModule will automatically throw the exception too if the module is not found whereas optionalModule does not.

Specified by:

getDependencies in interface Module

Overrides:

getDependencies in class AbstractModule

Parameters:

manager - The module manager handling this module.

Returns:

A collection of modules this module depends on.

Throws:

ModuleException

init

public void init(ModuleManager manager,
                 java.util.HashMap<java.lang.String,java.lang.Object> settings)
          throws ModuleException

Description copied from interface: Module

Initialises the module. After constructor, this is the first method called in the life cycle of a module. It should not perform anything time consuming or anything with notable outside side effects. It should only read the parameters and initialise the module so that it can later be started. Note that a module being initialised doesn't mean that it necessarily will ever be started.

A ModuleException may be thrown if something vital is missing from the parameters or they are not sensible. In some cases you may not want to throw an exception even if vital initialisation information is missing. If, for example, it is possible that the module is initialised in some other way between the init and the start method calls. A ModuleException may also be thrown at the start method if the module is still not initialised.

Specified by:

init in interface Module

Overrides:

init in class AbstractModule

Parameters:

manager - The module manager handling this module. You may keep a reference to it if needed.

Throws:

ModuleException

start

public void start(ModuleManager manager)
           throws ModuleException

Description copied from interface: Module

Starts the module. This will be called after init and getDependencies and signals that the module should now begin to perform whatever it was designed to do. This method call however should not block for long, so any time consuming tasks should be started in their own threads. You will typically get references to the required modules again in start using the findModule method of the manager and then store those references to instance variables for later use. You may throw a ModuleException if the module is not in a state where it can be started or it immediately becomes obvious that it cannot be started with the provided settings.

Specified by:

start in interface Module

Overrides:

start in class AbstractModule

Parameters:

manager - The module manager handling this module.

Throws:

ModuleException

stop

public void stop(ModuleManager manager)

Description copied from interface: Module

Stops the module. Should stop all threads used by the module, free any large data structures and perform other cleanup. It is possible that the module will be started again later with a start method call (and foregoing init and getDependencies calls). The module should be left in a state where this is possible.

Specified by:

stop in interface Module

Overrides:

stop in class AbstractModule

Parameters:

manager - The module manager handling this module.

startAutoThread

protected void startAutoThread()

autoThreadRun

protected void autoThreadRun()

saveTopicMap

public void saveTopicMap()

reloadTopicMap

public void reloadTopicMap()

lockRead

public boolean lockRead()

Description copied from interface: TopicMapManager

Locks the topic map for reading. You must eventually release the lock with unlockRead if this method succeeds and returns true.

Specified by:

lockRead in interface TopicMapManager

Returns:

True if the locking succeeded, false otherwise.

unlockRead

public void unlockRead()

Description copied from interface: TopicMapManager

Releases a previously acquired read lock.

Specified by:

unlockRead in interface TopicMapManager

lockWrite

public boolean lockWrite()

Description copied from interface: TopicMapManager

Locks the topic map for writing. You must eventually release the lock with unlockWrite if this method succeeds and returns true.

Specified by:

lockWrite in interface TopicMapManager

Returns:

True if the locking succeeded, false otherwise.

unlockWrite

public void unlockWrite()

Description copied from interface: TopicMapManager

Releases a previously acquired write lock.

Specified by:

unlockWrite in interface TopicMapManager

getTopicMap

public TopicMap getTopicMap()

Description copied from interface: TopicMapManager

Returns the topic map managed by this topic map manager.

Specified by:

getTopicMap in interface TopicMapManager

Returns:

The topic map of this manager.

fireTopicMapChanged

protected void fireTopicMapChanged(TopicMap old,
                                   TopicMap neu)

addTopicMapManagerListener

public void addTopicMapManagerListener(TopicMapManager.TopicMapManagerListener listener)

Description copied from interface: TopicMapManager

Adds a topic map listener that will be notified when the managed topic map is replaced with another topic map.

Specified by:

addTopicMapManagerListener in interface TopicMapManager

Parameters:

listener - The topic map listener.

removeTopicMapManagerListener

public void removeTopicMapManagerListener(TopicMapManager.TopicMapManagerListener listener)

Description copied from interface: TopicMapManager

Removes a topic map listener.

Specified by:

removeTopicMapManagerListener in interface TopicMapManager

Parameters:

listener - The listener.