Package org.optaplanner.core.api.domain.solution

## Interface Solution<S extends Score>

- Type Parameters:
    `S` - the `Score` type used by this use case

      @Deprecated
      public interface Solution<S extends Score>

  Deprecated.
  Use `PlanningScore`, `ProblemFactCollectionProperty` and `ProblemFactProperty` instead. Will be removed in 8.0.
  Retained for backwards compatibility with 6.x. This interface will be removed in 8.0.

  A solution represents a problem and a possible solution of that problem. A possible solution does not need to be optimal or even feasible. A Solution's variables do not even have to be initialized.

  A Solution is mutable. For scalability reasons, the same Solution instance, called the working solution, is continuously modified. It's cloned to recall the best solution.

  This annotation described declarative properties of the planning solution. The planning solution class must implement this interface which is needed to get/set state. But the planning solution class must also be annotated with `PlanningSolution` describes declarative properties.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods Deprecated Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `Collection<? extends Object>` | `getProblemFacts()` | Deprecated. Called by the `DroolsScoreDirector` when the `PlanningSolution` needs to be inserted into an empty `KieSession`.
    `S` | `getScore()` | Deprecated. Returns the `Score` of this Solution.
    `void` | `setScore​(S score)` | Deprecated. Called by the `Solver` when the `Score` of this Solution has been calculated.

- - ### Method Detail

    - #### getScore

          S getScore()

      Deprecated.
      Returns the `Score` of this Solution.
      Returns:
        null if the Solution is uninitialized or the last calculated `Score` is dirty the new `Score` has not yet been recalculated

    - #### setScore

          void setScore​(S score)

      Deprecated.
      Called by the `Solver` when the `Score` of this Solution has been calculated.
      Parameters:
        `score` - sometimes null

    - #### getProblemFacts

          Collection<? extends Object> getProblemFacts()

      Deprecated.
      Called by the `DroolsScoreDirector` when the `PlanningSolution` needs to be inserted into an empty `KieSession`. These facts can be used by the constraints. They don't change during planning (except through `ProblemFactChange` events).

      Do not include the planning entities as problem facts: they are automatically inserted into the `KieSession`.

      Returns:
        never null (although an empty collection is allowed), all the facts of this solution except for the planning entities