oracle.rules.sdk2.dictionary

Class AbstractDictionaryFinder

java.lang.Object

oracle.rules.sdk2.dictionary.AbstractDictionaryFinder

All Implemented Interfaces:

java.io.Serializable, DictionaryFinder

Direct Known Subclasses:

DecisionPointDictionaryFinder

public abstract class AbstractDictionaryFinder
extends java.lang.Object
implements DictionaryFinder

The base implementation of the DictionaryFinder interface. Concrete DictionaryFinder implementations should extend this class and implement the findDictionaryWithThisFinder method.

A concrete implementation should also override the canDetectChanges, mustPollForChanges, getModificationTime methods as necessary to reflect the behavior of the finder. These methods define how the finder interacts with the DictionaryLoader class when that class is used to load dictionaries. If the finder can not detect changes in the dictionaries it finds, then DictionaryLoader ignores it when determining if a dictionary needs to be reloaded. If mustPollForChanges returns true, then DictionaryFinder will synchronously poll the finder to see if a dictionary it found has been updated by invoking getModificationTime. Such a finder must override the getModificationTime method. Otherwise, DictionaryLoader expects asynchronous notification of changes from the finder. The finder invokes the DictionaryLoader.setReloadNeeded(DictionaryFQN fqn) method to notify that a dictionary was updated (a reference to the DictionaryLoader instance is available in this class).

It is recommended that DictionaryFinder implementations cache dictionaries that have been loaded. Caching can be enabled by invoking the enableCache method in the constructor of the implementation class. If the DictionaryFinder can detect changes to dictionaries, then it should invoke the invalidateCacheEntry method when a change is detected.

See Also:

DictionaryLoader, Serialized Form

Field Summary

Fields inherited from interface oracle.rules.sdk2.dictionary.DictionaryFinder

serialVersionUID

Method Summary

Modifier and Type	Method and Description
boolean	canDetectChanges() Indicates whether this finder is able to detect changes in the dictionaries that are found by this finder.
void	close() Close this finder to release held resources.
RuleDictionary	findDictionary(DictionaryFQN fqn) Finds a rule dictionary specified by its fully qualified name.
RuleDictionary	findDictionary(java.lang.String path) Find a dictionary given a logical, system independent path.
RuleDictionary	findDictionary(java.lang.String pkg, java.lang.String name) Finds a rule dictionary specified by the package and name.
RuleDictionary	findDictionaryWithThisFinder(DictionaryFQN fqn) Finds a rule dictionary with this finder.
RuleDictionary	findDictionaryWithThisFinder(java.lang.String path) Finds a rule dictionary with this finder.
AbstractDictionaryFinder	getChild() Returns the child finder or null if this finder does not have a child.
AbstractDictionaryFinder	getLastChild() Returns the last (leaf) child finder or this finder if this finder does not have a child.
long	getModificationTime(DictionaryFQN fqn) Returns a time in milliseconds indicating when the dictionary indentified by the DictionaryFQN was last modified.
long	getModificationTime(java.lang.String path) Returns a time in milliseconds indicating when the dictionary located by the path was last modified.
AbstractDictionaryFinder	getParent() Returns the parent finder or null if this finder does not have a parent.
void	invalidateCacheEntry(DictionaryFQN fqn)
void	invalidateCacheEntry(java.lang.String path)
boolean	mustPollForChanges() Indicates whether this finder must be polled to determine if a dictionary has been updated.

Methods inherited from class java.lang.Object

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

Method Detail

getParent

public AbstractDictionaryFinder getParent()

Returns the parent finder or null if this finder does not have a parent.

Returns:

the parent finder or null if this finder does not have a parent.

getChild

public AbstractDictionaryFinder getChild()

Returns the child finder or null if this finder does not have a child.

Returns:

the child finder or null if this finder does not have a child.

getLastChild

public AbstractDictionaryFinder getLastChild()

Returns the last (leaf) child finder or this finder if this finder does not have a child.

Returns:

the last (leaf) child finder or this finder if this finder does not have a child.

findDictionary

public RuleDictionary findDictionary(java.lang.String pkg,
                                     java.lang.String name)

Finds a rule dictionary specified by the package and name.

Specified by:

findDictionary in interface DictionaryFinder

Parameters:

pkg - fully qualified package name, e.g. foo.bar

name - unqualified name, e.g. MyDic

Returns:

the rule dictionary or null if the dictionary can not be found.

findDictionary

public RuleDictionary findDictionary(DictionaryFQN fqn)

Finds a rule dictionary specified by its fully qualified name.

Specified by:

findDictionary in interface DictionaryFinder

Parameters:

fqn - DictionaryFQN

Returns:

the rule dictionary or null if the dictionary can not be found.

findDictionaryWithThisFinder

public RuleDictionary findDictionaryWithThisFinder(DictionaryFQN fqn)

Finds a rule dictionary with this finder. Returns the dictionary identified by the specified fully qualified name or null if the dictionary can not be found.

This method is implemented by each concrete DictionaryFinder implementation. This method should always return a new handle for the dictionary it finds.

Parameters:

fqn - the fully qualified name of the dictionary to find.

See Also:

RuleDictionary.createHandle()

canDetectChanges

public boolean canDetectChanges()

Indicates whether this finder is able to detect changes in the dictionaries that are found by this finder. The default is true, indicating that changes can be detected. This method should be overridden by if the finder is unable to detect changes. This method is invoked from DictionaryLoader.

Returns:

true if changes to dictionaries found by this finder can be detected.

See Also:

DictionaryLoader

mustPollForChanges

public boolean mustPollForChanges()

Indicates whether this finder must be polled to determine if a dictionary has been updated. The default is true, indicating that polling is required. This method should be overridden by a finder that can asynchronously notify that a dictionary has been updated. This method is invoked from DictionaryLoader.

Returns:

true if polling for dictionary updates is required.

See Also:

DictionaryLoader, DictionaryLoader.setReloadNeeded(oracle.rules.sdk2.repository.DictionaryFQN)

getModificationTime

public long getModificationTime(DictionaryFQN fqn)

Returns a time in milliseconds indicating when the dictionary indentified by the DictionaryFQN was last modified. The default value of 0 is returned. This method should be overridden by a finder that must be polled for changes. This method is invoked from DictionaryLoader.

Returns:

the time in milliseconds of the last update to the dictionary.

See Also:

DictionaryLoader

findDictionary

public RuleDictionary findDictionary(java.lang.String path)

Find a dictionary given a logical, system independent path.

Specified by:

findDictionary in interface DictionaryFinder

Parameters:

path - the path used to find the dictionary

Returns:

RuleDictionary

findDictionaryWithThisFinder

public RuleDictionary findDictionaryWithThisFinder(java.lang.String path)

Finds a rule dictionary with this finder. Returns the dictionary located by the path or null if the dictionary can not be found.

This method is overridden by each concrete DictionaryFinder implementation. This method should always return a new handle for the dictionary it finds.

Parameters:

path - the path for the dictionary to find.

See Also:

RuleDictionary.createHandle()

getModificationTime

public long getModificationTime(java.lang.String path)

Returns a time in milliseconds indicating when the dictionary located by the path was last modified. The default value of 0 is returned. This method should be overridden by a finder that must be polled for changes. This method is invoked from DictionaryLoader.

Returns:

the time in milliseconds of the last update to the dictionary.

See Also:

DictionaryLoader

close

public void close()

Close this finder to release held resources. This method should be overridden. A default implementation included for backwards compability.

Specified by:

close in interface DictionaryFinder

invalidateCacheEntry

public void invalidateCacheEntry(DictionaryFQN fqn)

invalidateCacheEntry

public void invalidateCacheEntry(java.lang.String path)