5.2. Choose a Score Definition

Each Score implementation also has a ScoreDefinition implementation. For example: SimpleScore is defined by SimpleScoreDefinition.

Note

To properly write a Score to database (with JPA/Hibernate) or to XML/JSON (with XStream/JAXB), see the integration chapter.

5.2.1. SimpleScore

A SimpleScore has a single int value, for example -123. It has a single score level. 

  <scoreDirectorFactory>
    <scoreDefinitionType>SIMPLE</scoreDefinitionType>
    ...
  </scoreDirectorFactory>

Variants of this scoreDefinitionType:

  • SIMPLE_LONG: Uses SimpleLongScore which has a long value instead of an int value.
  • SIMPLE_DOUBLE: Uses SimpleDoubleScore which has a double value instead of an int value. Not recommended to use.
  • SIMPLE_BIG_DECIMAL: Uses SimpleBigDecimalScore which has a BigDecimal value instead of an int value.

5.2.2. HardSoftScore (Recommended)

A HardSoftScore has a hard int value and a soft int value, for example -123hard/-456soft. It has 2 score levels (hard and soft). 

  <scoreDirectorFactory>
    <scoreDefinitionType>HARD_SOFT</scoreDefinitionType>
    ...
  </scoreDirectorFactory>

Variants of this scoreDefinitionType:

  • HARD_SOFT_LONG: Uses HardSoftLongScore which has long values instead of int values.
  • HARD_SOFT_DOUBLE: Uses HardSoftDoubleScore which has double values instead of int values. Not recommended to use.
  • HARD_SOFT_BIG_DECIMAL: Uses HardSoftBigDecimalScore which has BigDecimal values instead of int values.

5.2.3. HardMediumSoftScore

A HardMediumSoftScore which has a hard int value, a medium int value and a soft int value, for example -123hard/-456medium/-789soft. It has 3 score levels (hard, medium and soft). 

  <scoreDirectorFactory>
    <scoreDefinitionType>HARD_MEDIUM_SOFT</scoreDefinitionType>
    ...
  </scoreDirectorFactory>

Variants of this scoreDefinitionType:

  • HARD_MEDIUM_SOFT_LONG: Uses HardMediumSoftLongScore which has long values instead of int values.

5.2.4. BendableScore

A BendableScore has a configurable number of score levels. It has an array of hard int values and an array of soft int value, for example with 2 hard levels and 3 soft levels, the score can be -123/-456/-789/-012/-345. 

  <scoreDirectorFactory>
    <scoreDefinitionType>BENDABLE</scoreDefinitionType>
    <bendableHardLevelsSize>2</bendableHardLevelsSize>
    <bendableSoftLevelsSize>3</bendableSoftLevelsSize>
    ...
  </scoreDirectorFactory>

The number of hard and soft score levels needs to be set at configuration time. It is not flexible to change during solving.

Variants of this scoreDefinitionType:

  • BENDABLE_LONG: Uses BendableLongScore which has long values instead of int values.
  • BENDABLE_BIG_DECIMAL: Uses BendableBigDecimalScore which has BigDecimal values instead of int values.

5.2.5. Implementing a Custom Score

The ScoreDefinition interface defines the score representation.

To implement a custom Score, you will also need to implement a custom ScoreDefinition. Extend AbstractScoreDefinition (preferably by copy pasting HardSoftScoreDefinition) and start from there.

Then hook your custom ScoreDefinition in your SolverConfig.xml : 

  <scoreDirectorFactory>
    <scoreDefinitionClass>...MyScoreDefinition</scoreDefinitionClass>
    ...
  </scoreDirectorFactory>

To have it integrate seamlessly with JPA/Hibernate, XStream, …​ you might need to write some glue code.