变量监听器损坏

Question

我在玩自定义阴影变量和自定义变量侦听器。我发现当“Leading Exam”发生变化时，“Exam timetableling”示例使用自定义影子变量来更新“Following Exams”。 所以我断言在这个问题中提出的问题是真的Custom VariableListener updating more than one shadow variables 我在下面的考试类中添加了第二个影子变量，它引用了变量“周期”，然后在LeadingExam 计划实体的变量侦听器中（PeriodUpdatingVariableListener）我更新两个变量。

这是“FollowingExam”类的代码

@PlanningEntity
@XStreamAlias("FollowingExam")
public class FollowingExam extends Exam {

protected LeadingExam leadingExam;

// Shadow variables
protected Period period;
protected Integer var;

@CustomShadowVariable(variableListenerClass = PeriodUpdatingVariableListener.class, sources = {
        @CustomShadowVariable.Source(entityClass = LeadingExam.class, variableName = "period") })
public Period getPeriod() {
    return period;
}

public void setPeriod(Period period) {
    this.period = period;
}

@CustomShadowVariable(variableListenerRef = @PlanningVariableReference(variableName = "period"))
public Integer getVar() {
    return var;
}

public void setVar(Integer var) {
    this.var = var;
}

public LeadingExam getLeadingExam() {
    return leadingExam;
}

public void setLeadingExam(LeadingExam leadingExam) {
    this.leadingExam = leadingExam;
}

}

在“PeriodUpdatingVariableListener”中我有下一个代码

public class PeriodUpdatingVariableListener implements VariableListener<LeadingExam> {

public void beforeEntityAdded(ScoreDirector scoreDirector, LeadingExam leadingExam) {
    // Do nothing
}

public void afterEntityAdded(ScoreDirector scoreDirector, LeadingExam leadingExam) {
    updatePeriod(scoreDirector, leadingExam);
}

public void beforeVariableChanged(ScoreDirector scoreDirector, LeadingExam leadingExam) {
    // Do nothing
}

public void afterVariableChanged(ScoreDirector scoreDirector, LeadingExam leadingExam) {
    updatePeriod(scoreDirector, leadingExam);
}

public void beforeEntityRemoved(ScoreDirector scoreDirector, LeadingExam leadingExam) {
    // Do nothing
}

public void afterEntityRemoved(ScoreDirector scoreDirector, LeadingExam leadingExam) {
    // Do nothing
}

protected void updatePeriod(ScoreDirector scoreDirector, LeadingExam leadingExam) {
    Period period = leadingExam.getPeriod();
    for (FollowingExam followingExam : leadingExam.getFollowingExamList()) {
        scoreDirector.beforeVariableChanged(followingExam, "period");
        followingExam.setPeriod(period);
        scoreDirector.afterVariableChanged(followingExam, "period");

        //additional lines of code to update the "var" variable
        Integer var = followingExam.getVar();
        if(var == null){
            var = new Integer(1);
        }
        else var++;
        scoreDirector.beforeVariableChanged(followingExam, "var");
        followingExam.setVar(var);
        scoreDirector.afterVariableChanged(followingExam, "var");

    }
}

}

OptaPlanner 注册这是另一个影子变量似乎也没有问题，因为我在运行应用程序时收到此消息

2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE     Model annotations parsed for Solution Examination:
2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE         Entity Exam:
2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE             Variable room (genuine)
2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE         Entity LeadingExam:
2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE             Variable period (genuine)
2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE         Entity FollowingExam:
2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE             Variable period (shadow)
2016-04-11 15:26:15,309 [AWT-EventQueue-0] TRACE             Variable var (shadow)

我得到的错误是下一个错误，这个错误只在我将环境模式更改为 FULL_ASSERT 时出现，但是当它保留为默认 REPRODUCIBLE 时，它运行没有任何错误。

Caused by: java.lang.IllegalStateException: VariableListener corruption: the entity (426)'s shadow variable (FollowingExam.var)'s corrupted value (null) changed to uncorrupted value (1) after all VariableListeners were triggered without changes to the genuine variables.
Probably the VariableListener class for that shadow variable (FollowingExam.var) forgot to update it when one of its sources changed after completedAction (Initial score calculated).
at org.optaplanner.core.impl.score.director.AbstractScoreDirector.assertShadowVariablesAreNotStale(AbstractScoreDirector.java:349)
at org.optaplanner.core.impl.solver.recaller.BestSolutionRecaller.solvingStarted(BestSolutionRecaller.java:84)
at org.optaplanner.core.impl.solver.DefaultSolver.solvingStarted(DefaultSolver.java:196)
at org.optaplanner.core.impl.solver.DefaultSolver.solve(DefaultSolver.java:175)
at org.optaplanner.examples.common.business.SolutionBusiness.solve(SolutionBusiness.java:307)
at org.optaplanner.examples.common.swingui.SolverAndPersistenceFrame$SolveWorker.doInBackground(SolverAndPersistenceFrame.java:287)
at org.optaplanner.examples.common.swingui.SolverAndPersistenceFrame$SolveWorker.doInBackground(SolverAndPersistenceFrame.java:1)
at javax.swing.SwingWorker$1.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at javax.swing.SwingWorker.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Answer 1

变量监听器中的这段代码不好：

    Integer var = followingExam.getVar();
    ...
    var++;
    ...
    followingExam.setVar(var);
    ...

如果它被多次调用，var 会改变，即使真正的 var 没有改变。如果在评分规则中使用该 var，则同一解决方案的解决方案的分数并不总是相同。

影子变量是基于至少 1 个真实变量（直接或间接）的公式结果的缓存。例如阴影 C = 真正的 A + 问题属性 B。因此，如果 B 为 10，且 A 的范围为 1 到 5，则如果 A 为 1，则 C 为 11，如果 A 为 2，则为 12，以此类推。