Package org.optaplanner.core.impl.heuristic.selector.move.generic

Class SwapMove<Solution_>

java.lang.Object

org.optaplanner.core.impl.heuristic.move.AbstractMove<Solution_>

org.optaplanner.core.impl.heuristic.selector.move.generic.SwapMove<Solution_>

Type Parameters:

Solution_ - the solution type, the class with the PlanningSolution annotation

All Implemented Interfaces:

Move<Solution_>

Direct Known Subclasses:

ChainedSwapMove

public class SwapMove<Solution_>
extends AbstractMove<Solution_>

Field Summary

Fields

Modifier and Type	Field	Description
protected final Object	leftEntity
protected final Object	rightEntity
protected final List<GenuineVariableDescriptor<Solution_>>	variableDescriptorList

Constructor Summary

Constructors

Constructor	Description
SwapMove(List<GenuineVariableDescriptor<Solution_>> variableDescriptorList, Object leftEntity, Object rightEntity)

Method Summary

Modifier and Type	Method	Description
protected void	appendVariablesToString(StringBuilder s, Object entity)
SwapMove<Solution_>	createUndoMove(ScoreDirector<Solution_> scoreDirector)	Called before the move is done, so the move can be evaluated and then be undone without resulting into a permanent change in the solution.
protected void	doMoveOnGenuineVariables(ScoreDirector<Solution_> scoreDirector)	Like AbstractMove.doMoveOnly(ScoreDirector) but without the ScoreDirector.triggerVariableListeners() call (because AbstractMove.doMoveOnly(ScoreDirector) already does that).
boolean	equals(Object o)
Object	getLeftEntity()
Collection<? extends Object>	getPlanningEntities()	Returns all planning entities that are being changed by this move.
Collection<? extends Object>	getPlanningValues()	Returns all planning values that entities are being assigned to by this move.
Object	getRightEntity()
String	getSimpleMoveTypeDescription()	Describes the move type for statistical purposes.
int	hashCode()
boolean	isMoveDoable(ScoreDirector<Solution_> scoreDirector)	Called before a move is evaluated to decide whether the move can be done and evaluated.
SwapMove<Solution_>	rebase(ScoreDirector<Solution_> destinationScoreDirector)	Rebases a move from an origin ScoreDirector to another destination ScoreDirector which is usually on another Thread or JVM.
String	toString()

Methods inherited from class org.optaplanner.core.impl.heuristic.move.AbstractMove

doMove, doMoveOnly, rebaseArray, rebaseList

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

variableDescriptorList

protected final List<GenuineVariableDescriptor<Solution_>> variableDescriptorList

leftEntity

protected final Object leftEntity

rightEntity

protected final Object rightEntity

Constructor Details

SwapMove

public SwapMove(List<GenuineVariableDescriptor<Solution_>> variableDescriptorList,
 Object leftEntity,
 Object rightEntity)

Method Details

getLeftEntity

public Object getLeftEntity()

getRightEntity

public Object getRightEntity()

isMoveDoable

public boolean isMoveDoable(ScoreDirector<Solution_> scoreDirector)

Description copied from interface: Move

Called before a move is evaluated to decide whether the move can be done and evaluated. A Move is not doable if:

• Either doing it would change nothing in the PlanningSolution.
• Either it's simply not possible to do (for example due to built-in hard constraints).

It is recommended to keep this method implementation simple: do not use it in an attempt to satisfy normal hard and soft constraints.

Although you could also filter out non-doable moves in for example the MoveSelector or MoveListFactory, this is not needed as the Solver will do it for you.

Parameters:

scoreDirector - the ScoreDirector not yet modified by the move.

Returns:

true if the move achieves a change in the solution and the move is possible to do on the solution.

createUndoMove

public SwapMove<Solution_> createUndoMove(ScoreDirector<Solution_> scoreDirector)

Description copied from class: AbstractMove

Called before the move is done, so the move can be evaluated and then be undone without resulting into a permanent change in the solution.

Specified by:

createUndoMove in class AbstractMove<Solution_>

Parameters:

scoreDirector - the ScoreDirector not yet modified by the move.

Returns:

an undoMove which does the exact opposite of this move.

rebase

public SwapMove<Solution_> rebase(ScoreDirector<Solution_> destinationScoreDirector)

Description copied from interface: Move

Rebases a move from an origin ScoreDirector to another destination ScoreDirector which is usually on another Thread or JVM. The new move returned by this method translates the entities and problem facts to the destination PlanningSolution of the destination ScoreDirector, That destination PlanningSolution is a deep planning clone (or an even deeper clone) of the origin PlanningSolution that this move has been generated from.

That new move does the exact same change as this move, resulting in the same PlanningSolution state, presuming that destination PlanningSolution was in the same state as the original PlanningSolution to begin with.

Generally speaking, an implementation of this method iterates through every entity and fact instance in this move, translates each one to the destination ScoreDirector with ScoreDirector.lookUpWorkingObject(Object) and creates a new move instance of the same move type, using those translated instances.

The destination PlanningSolution can be in a different state than the original PlanningSolution. So, rebasing can only depend on the identity of planning entities and planning facts, which is usually declared by a PlanningId on those classes. It must not depend on the state of the planning variables. One thread might rebase a move before, amid or after another thread does that same move instance.

This method is thread-safe.

Parameters:

destinationScoreDirector - never null, the ScoreDirector.getWorkingSolution() that the new move should change the planning entity instances of.

Returns:

never null, a new move that does the same change as this move on another solution instance

doMoveOnGenuineVariables

protected void doMoveOnGenuineVariables(ScoreDirector<Solution_> scoreDirector)

Description copied from class: AbstractMove

Like AbstractMove.doMoveOnly(ScoreDirector) but without the ScoreDirector.triggerVariableListeners() call (because AbstractMove.doMoveOnly(ScoreDirector) already does that).

Specified by:

doMoveOnGenuineVariables in class AbstractMove<Solution_>

Parameters:

scoreDirector - never null

getSimpleMoveTypeDescription

public String getSimpleMoveTypeDescription()

Description copied from interface: Move

Describes the move type for statistical purposes. For example "ChangeMove(Process.computer)".

The format is not formalized. Never parse the String returned by this method.

Returns:

never null

getPlanningEntities

public Collection<? extends Object> getPlanningEntities()

Description copied from interface: Move

Returns all planning entities that are being changed by this move. Required for AcceptorType.ENTITY_TABU.

This method is only called after Move.doMove(ScoreDirector) (which might affect the return values).

Duplicate entries in the returned Collection are best avoided. The returned Collection is recommended to be in a stable order. For example: use List or LinkedHashSet, but not HashSet.

Returns:

never null

getPlanningValues

public Collection<? extends Object> getPlanningValues()

Description copied from interface: Move

Returns all planning values that entities are being assigned to by this move. Required for AcceptorType.VALUE_TABU.

This method is only called after Move.doMove(ScoreDirector) (which might affect the return values).

Duplicate entries in the returned Collection are best avoided. The returned Collection is recommended to be in a stable order. For example: use List or LinkedHashSet, but not HashSet.

Returns:

never null

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

appendVariablesToString

protected void appendVariablesToString(StringBuilder s,
 Object entity)