net.sourceforge.jsl
Class AbstractOpenClosedListSearch

java.lang.Object
  |
  +--net.sourceforge.jsl.AbstractOpenClosedListSearch

All Implemented Interfaces:

Search

Direct Known Subclasses:

AbstractScoringSearch, BreadthFirstSearch, DepthFirstSearch

public abstract class AbstractOpenClosedListSearch

extends Object

implements Search

Abstract base class for a search that works using open and closed list for nodes already searched and nodes still to be processed.

Field Summary

protected Collection	closedList
protected boolean	closeGoal
protected int	expandCnt
protected boolean	expandGoal
protected int	maxClosed
protected int	maxDepth
protected int	maxExpands
protected int	maxOpen
protected List	openList
protected SearchNode	seed
protected boolean	useHashSet

Constructor Summary

AbstractOpenClosedListSearch()

Method Summary

protected void	checkForEmergencyStop()
protected boolean	cutOff(SearchNode searchNode)
protected void	expand(SearchNode searchNode)
Collection	getClosedList() Returns the unordered list of nodes already searched.
boolean	getCloseGoal()
boolean	getExpandGoal() Returns whether nodes that have been identified as goals shall be expanded and its successor be added to the open list.
int	getMaxClosed()
int	getMaxDepth()
int	getMaxExpands()
int	getMaxOpen()
List	getOpenList() Returns the list of open nodes yet to be searched in order in which they are scheduled for processing.
SearchNode	search() Searches for the search node that is marked as a goal and returns it.
Collection	search(int maxGoals) Searches for search nodes marked as a goal and returns them.
void	setCloseGoal(boolean closeGoal)
void	setExpandGoal(boolean expandGoal) Sets whether nodes that have been identified as goals shall be expanded and its successor be added to the open list.
void	setMaxClosed(int maxClosed)
void	setMaxDepth(int maxDepth)
void	setMaxExpands(int maxExpands)
void	setMaxOpen(int maxOpen)
void	setSeed(SearchNode seed) Sets the seed of the search, i.e. the root node of the search.
void	setUseHashSet(boolean useHashSet) Determines whether nodes in the closed list shall be stored using a HashSet.
protected abstract void	writeState(SearchNode state)
protected abstract void	writeStates(Collection states)

Methods inherited from class java.lang.Object

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

Field Detail

seed

protected SearchNode seed

maxDepth

protected int maxDepth

maxExpands

protected int maxExpands

maxClosed

protected int maxClosed

maxOpen

protected int maxOpen

expandCnt

protected int expandCnt

openList

protected List openList

closedList

protected Collection closedList

expandGoal

protected boolean expandGoal

closeGoal

protected boolean closeGoal

useHashSet

protected boolean useHashSet

Constructor Detail

AbstractOpenClosedListSearch

public AbstractOpenClosedListSearch()

Method Detail

setSeed

public void setSeed(SearchNode seed)

Description copied from interface: Search

Sets the seed of the search, i.e. the root node of the search.

Specified by:

setSeed in interface Search

Parameters:

seed - the root node of the search

search

public Collection search(int maxGoals)
                  throws SearchException

Description copied from interface: Search

Searches for search nodes marked as a goal and returns them. The search stops either when there are no nodes left to process or the maximum number of goals are reached.

Specified by:

search in interface Search

Parameters:

maxGoals - the maximum number of goals to search for.

Returns:

a collection of all goal nodes found; if no goals have been found an empty collection is returned

Throws:

SearchException - signals an abnormal termination of the search

search

public SearchNode search()
                  throws SearchException

Description copied from interface: Search

Searches for the search node that is marked as a goal and returns it.

Specified by:

search in interface Search

Returns:

the first goal search node found or null if none was found

Throws:

SearchException - signals an abnormal termination of the search

getClosedList

public Collection getClosedList()

Returns the unordered list of nodes already searched.

Returns:

the list of closed nodes

getOpenList

public List getOpenList()

Returns the list of open nodes yet to be searched in order in which they are scheduled for processing.

Returns:

the list of open nodes

setUseHashSet

public void setUseHashSet(boolean useHashSet)

Determines whether nodes in the closed list shall be stored using a HashSet. If this feature is turned on (default) Object.hashCode() must be implemented properly in the custom SearchNode implementation.

Parameters:

useHashSet - true if a HashSet shall be used to store the closed list, false to use an ArrayList

getExpandGoal

public boolean getExpandGoal()

Returns whether nodes that have been identified as goals shall be expanded and its successor be added to the open list.

Returns:

true if goals will be expanded, false otherwise

setExpandGoal

public void setExpandGoal(boolean expandGoal)

Sets whether nodes that have been identified as goals shall be expanded and its successor be added to the open list.

Parameters:

expandGoal - true if goals will be expanded, false otherwise

getMaxDepth

public int getMaxDepth()

setMaxDepth

public void setMaxDepth(int maxDepth)

getMaxClosed

public int getMaxClosed()

getMaxExpands

public int getMaxExpands()

getMaxOpen

public int getMaxOpen()

setMaxClosed

public void setMaxClosed(int maxClosed)

setMaxExpands

public void setMaxExpands(int maxExpands)

setMaxOpen

public void setMaxOpen(int maxOpen)

getCloseGoal

public boolean getCloseGoal()

setCloseGoal

public void setCloseGoal(boolean closeGoal)

expand

protected void expand(SearchNode searchNode)
               throws SearchException

SearchException

writeState

protected abstract void writeState(SearchNode state)

writeStates

protected abstract void writeStates(Collection states)

checkForEmergencyStop

protected void checkForEmergencyStop()
                              throws SearchException

SearchException

cutOff

protected boolean cutOff(SearchNode searchNode)