Optaplanner计划变量不可为空但仍分配给null

Question

计划变量不可为空。当我在变量监听器中为我的阴影值打印出计划实体时，仍然在计划过程中NULL值仍然分配给计划变量??

规划实体：

 // Planning variables: changes during planning, between score calculations.
    @PlanningVariable(valueRangeProviderRefs = {"numberRange"})
    private Integer number;

    @ValueRangeProvider(id = "numberRange")
    private List<Integer> numberRange;

    @CustomShadowVariable(variableListenerClass = BoxUpdatingVariableListener.class,
            sources = {@PlanningVariableReference(variableName = "number")})
    private Integer shaodowNumber;

变量监听器：

 protected void updateShadowNumber(ScoreDirector scoreDirector, Box sourceBox) {
        System.out.println("number:"+sourceBox.getNumber());
    }

部分结果：

02:24:46.832 [main        ] INFO  Solving started: time spent (74), best score (-3init/-90), environment mode (FULL_ASSERT), random (JDK with seed 0).
number:1
number:null
number:2
number:null
number:3
number:null
number:4
number:null
number:5
number:null
number:6
number:null
number:7
number:null
number:7
number:7
number:null
number:null
02:24:46.883 [main        ] DEBUG     CH step (0), time spent (125), score (-2init/-43), selected move count (7), picked move (Box-1 {null -> 7}).
number:1
number:null
number:2
number:null
number:3
number:null
number:4
number:null
number:5
number:null
number:6
number:null
number:6
number:7
number:6
number:null

Answer 1

这通常是不运行施工阶段的结果

https://docs.optaplanner.org/7.14.0.Final/optaplanner-docs/html_single/index.html#constructionHeuristics

比如这样

<constructionHeuristic>
  <constructionHeuristicType>STRONGEST_FIT_DECREASING</constructionHeuristicType>
</constructionHeuristic>