com.haley.haleyrules.jsr94
Class StatefulRuleSessionImpl

java.lang.Object
  |
  +--com.haley.haleyrules.jsr94.HaleyRuleSession
        |
        +--com.haley.haleyrules.jsr94.StatefulRuleSessionImpl

All Implemented Interfaces:

javax.rules.RuleSession, java.io.Serializable, javax.rules.StatefulRuleSession

public class StatefulRuleSessionImpl

extends HaleyRuleSession

implements javax.rules.StatefulRuleSession

This class implements StatefulRuleSession interface. For Haley rules engine, there can be only one thread to access a StatefulRuleSession at any one time.

The StatefulRuleSession is a representation of a stateful rules engine session. A stateful rules engine session exposes a stateful rule execution API to an underlying rules engine. The session allows arbitrary objects to be added and removed to and from the rule session state. Additionally, objects currently part of the rule session state may be updated.

There are inherently side-effects to adding objects to the rule session state. The execution of a RuleExecutionSet can add, remove and update objects in the rule session state. The objects in the rule session state are therefore dependent on the rules within the RuleExecutionSet as well as the rule engine vendor's specific rule engine behavior.

Handle instances are used by the rule engine vendor to track Objects added to the rule session state. This allows multiple instances of equivalent Objects to be added to the session state and identified, even after serialization.

See Also:

Serialized Form

Method Summary

javax.rules.Handle	addObject(java.lang.Object object) Adds a given object to the rule session state of this rule session.
java.util.List	addObjects(java.util.List objList) Adds a List of Objects to the rule session state of this rule session.
boolean	containsObject(javax.rules.Handle objectHandle)
void	executeRules() Executes the rules in the bound rule execution set using the objects present in the rule session state.
java.util.List	getHandles() Returns a List of the Handles being used for object identity.
java.lang.Object	getObject(javax.rules.Handle handle) Returns the Object within the StatefulRuleSession associated with a Handle.
java.util.List	getObjects() Returns a List of all objects in the rule session state of this rule session.
java.util.List	getObjects(javax.rules.ObjectFilter filter) Returns a List over the objects in rule session state of this rule session.
int	getType() Gets the type identifier for this RuleSession.
void	release() Releases all resources used by this rule session.
void	removeObject(javax.rules.Handle handle) Removes a given object from the rule session state of this rule session.
void	reset() Resets this rule session.
void	updateObject(javax.rules.Handle objectHandle, java.lang.Object newObject) Notifies the rules engine that a given object in the rule session state has changed.

Methods inherited from class com.haley.haleyrules.jsr94.HaleyRuleSession

getRuleExecutionSetMetadata

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.rules.RuleSession

getRuleExecutionSetMetadata

Method Detail

containsObject

public boolean containsObject(javax.rules.Handle objectHandle)
                       throws javax.rules.InvalidRuleSessionException,
                              javax.rules.InvalidHandleException

Specified by:

containsObject in interface javax.rules.StatefulRuleSession

Parameters:

objectHandle - the handle to the target object.

Returns:

true if the given object is contained within the rule session state of this rule session.

Throws:

javax.rules.InvalidRuleSessionException - on illegal rule session state.

javax.rules.InvalidHandleException -

addObject

public javax.rules.Handle addObject(java.lang.Object object)
                             throws javax.rules.InvalidRuleSessionException

Adds a given object to the rule session state of this rule session. The argument to this method is Object because in the non-managed environment, not all objects should have to implement Serializable. If the RuleSession is Serializable and it contains non-serializable fields a runtime exception will be thrown.

Specified by:

addObject in interface javax.rules.StatefulRuleSession

Parameters:

object - the object to be added.

Returns:

the Handle for the newly added Object

Throws:

InvalidRuleSessionExceptionAdds - on illegal rule session state.

addObjects

public java.util.List addObjects(java.util.List objList)
                          throws javax.rules.InvalidRuleSessionException

Adds a List of Objects to the rule session state of this rule session.

Specified by:

addObjects in interface javax.rules.StatefulRuleSession

Parameters:

objList - the objects to be added.

Returns:

a List of Handles, one for each added Object. The List must be ordered in the same order as the input objList.

Throws:

javax.rules.InvalidRuleSessionException - on illegal rule session state.

updateObject

public void updateObject(javax.rules.Handle objectHandle,
                         java.lang.Object newObject)
                  throws javax.rules.InvalidRuleSessionException,
                         javax.rules.InvalidHandleException

Notifies the rules engine that a given object in the rule session state has changed. The semantics of this call are equivalent to calling removeObject followed by addObject. The original Handle is rebound to the new value for the Object however.

Specified by:

updateObject in interface javax.rules.StatefulRuleSession

Parameters:

objectHandle - Handle - the handle to the original object.

newObject - the new object to bind to the handle.

Throws:

javax.rules.InvalidRuleSessionException - on illegal rule session state.

javax.rules.InvalidHandleException - if the input Handle is no longer valid

removeObject

public void removeObject(javax.rules.Handle handle)
                  throws javax.rules.InvalidHandleException,
                         javax.rules.InvalidRuleSessionException

Removes a given object from the rule session state of this rule session.

Specified by:

removeObject in interface javax.rules.StatefulRuleSession

Parameters:

handle - the handle to the object to be removed from the rule session state.

Throws:

javax.rules.InvalidHandleException - if the input Handle is no longer valid

javax.rules.InvalidRuleSessionException - on illegal rule session state.

getObjects

public java.util.List getObjects()
                          throws javax.rules.InvalidRuleSessionException

Returns a List of all objects in the rule session state of this rule session. The objects should pass the default filter test of the default RuleExecutionSet filter (if present). This may not neccessarily include all objects added by calls to addObject, and may include Objects created by side-effects. The execution of a RuleExecutionSet can add, remove and update objects as part of the rule session state. Therefore the rule session state is dependent on the rules that are part of the executed RuleExecutionSet as well as the rule vendor's specific rule engine behavior.

Specified by:

getObjects in interface javax.rules.StatefulRuleSession

Returns:

a List of all objects part of the rule session state.

Throws:

javax.rules.InvalidRuleSessionException - on illegal rule session state.

getHandles

public java.util.List getHandles()
                          throws javax.rules.InvalidRuleSessionException

Returns a List of the Handles being used for object identity.

Specified by:

getHandles in interface javax.rules.StatefulRuleSession

Returns:

a List of Handles present in the current state of the rule session.

Throws:

javax.rules.InvalidRuleSessionException -

getObjects

public java.util.List getObjects(javax.rules.ObjectFilter filter)
                          throws javax.rules.InvalidRuleSessionException

Returns a List over the objects in rule session state of this rule session. The objects should pass the filter test on the specified ObjectFilter. This may not neccessarily include all objects added by calls to addObject, and may include Objects created by side-effects. The execution of a RuleExecutionSet can add, remove and update objects as part of the rule session state. Therefore the rule session state is dependent on the rules that are part of the executed RuleExecutionSet as well as the rule vendor's specific rule engine behavior.

Specified by:

getObjects in interface javax.rules.StatefulRuleSession

Parameters:

filter - the object filter.

Returns:

a List of all the objects in the rule session state of this rule session based upon the given object filter.

Throws:

javax.rules.InvalidRuleSessionException - on illegal rule session state.

executeRules

public void executeRules()
                  throws javax.rules.InvalidRuleSessionException

Executes the rules in the bound rule execution set using the objects present in the rule session state. This will typically modify the rule session state - and may add, remove or update Objects bound to Handles.

Specified by:

executeRules in interface javax.rules.StatefulRuleSession

Throws:

javax.rules.InvalidRuleSessionException - - on illegal rule session state.

reset

public void reset()
           throws javax.rules.InvalidRuleSessionException

Resets this rule session. Calling this method will bring the rule session state to its initial state for this rule session and will reset any other state associated with this rule session. A reset will not reset the state on the default object filter for a RuleExecutionSet.

Specified by:

reset in interface javax.rules.StatefulRuleSession

Throws:

javax.rules.InvalidRuleSessionException - on illegal rule session state.

getObject

public java.lang.Object getObject(javax.rules.Handle handle)
                           throws javax.rules.InvalidHandleException,
                                  javax.rules.InvalidRuleSessionException

Returns the Object within the StatefulRuleSession associated with a Handle.

Specified by:

getObject in interface javax.rules.StatefulRuleSession

Parameters:

handle - Handle

Returns:

Object

Throws:

javax.rules.InvalidHandleException - if the Handle is no longer valid for this StatefulRuleSession

javax.rules.InvalidRuleSessionException -

getType

public int getType()
            throws javax.rules.InvalidRuleSessionException

Gets the type identifier for this RuleSession. The type identifiers are defined in the RuleRuntime interface

Specified by:

getType in interface javax.rules.RuleSession

Overrides:

getType in class HaleyRuleSession

Returns:

stateful rule session type

Throws:

javax.rules.InvalidRuleSessionException - on illegal rule session state

release

public void release()
             throws javax.rules.InvalidRuleSessionException

Releases all resources used by this rule session. This method renders this rule session unusable until it is reacquired through the RuleRuntime

Specified by:

release in interface javax.rules.RuleSession

Overrides:

release in class HaleyRuleSession

Throws:

javax.rules.InvalidRuleSessionException -