多线程时OptaPlanner报错（无法查找外部对象）

Question

我用OptaPlanner开发了一个优化模块，但是在多线程时遇到了错误。请注意，该模块在禁用多线程时工作。我尝试了几个 OptaPlanner 版本（8.4、8.1、7.51）和不同的 JDK（16 和 14）。

我使用了一个简单的求解器配置文件

**

我的策划实体也很直接:

**

@PlanningSolution public class SuccessPromotion  {
    
    @ProblemFactCollectionProperty
    public ArrayList<RCT> rcts;
    @PlanningEntityCollectionProperty
    public ArrayList<RCT_Planning> rcts_promos;
    @ValueRangeProvider(id = "availablePromotion")
    @ProblemFactCollectionProperty
    public List<int[]> promotions;
    @PlanningScore
    public HardSoftScore score;
    @PlanningId
    public String name; //Constructors //Getter & Setter }

** 我得到的错误如下： **

Exception in thread "main" java.lang.IllegalStateException: The move thread with moveThreadIndex (3) has thrown an exception. Relayed here in the parent thread. at org.optaplanner.core.impl.heuristic.thread.OrderByMoveIndexBlockingQueue.take(OrderByMoveIndexBlockingQueue.java:147) at org.optaplanner.core.impl.localsearch.decider.MultiThreadedLocalSearchDecider.forageResult(MultiThreadedLocalSearchDecider.java:188) at org.optaplanner.core.impl.localsearch.decider.MultiThreadedLocalSearchDecider.decideNextStep(MultiThreadedLocalSearchDecider.java:159) at org.optaplanner.core.impl.localsearch.DefaultLocalSearchPhase.solve(DefaultLocalSearchPhase.java:71) at org.optaplanner.core.impl.solver.AbstractSolver.runPhases(AbstractSolver.java:99) at org.optaplanner.core.impl.solver.DefaultSolver.solve(DefaultSolver.java:189) at test.RealSolver.main(RealSolver.java:140) Caused by: java.lang.IllegalArgumentException: The externalObject ([I@5ce1e52a) cannot be looked up. Some functionality, such as multithreaded solving, requires this ability. Maybe add an @PlanningId annotation on an identifier property of the class (class [I). Or otherwise, maybe change the @PlanningSolution annotation's LookUpStrategyType (not recommended). at org.optaplanner.core.impl.domain.lookup.NoneLookUpStrategy.lookUpWorkingObject(NoneLookUpStrategy.java:44) at org.optaplanner.core.impl.domain.lookup.LookUpManager.lookUpWorkingObject(LookUpManager.java:76) at org.optaplanner.core.impl.score.director.AbstractScoreDirector.lookUpWorkingObject(AbstractScoreDirector.java:512) at org.optaplanner.core.impl.heuristic.selector.move.generic.ChangeMove.rebase(ChangeMove.java:83) at org.optaplanner.core.impl.heuristic.selector.move.generic.ChangeMove.rebase(ChangeMove.java:31) at org.optaplanner.core.impl.heuristic.thread.MoveThreadRunner.run(MoveThreadRunner.java:140) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:834) **

Answer 1

您的错误信息是

The externalObject ([I@5ce1e52a) cannot be looked up. Some functionality, such as multithreaded solving, requires this ability. Maybe add an @PlanningId annotation on an identifier property of the class (class [I).

那 class[I 谈论的是您的规划价值 class (int[])，而不是您的规划实体 class (ArrayList<RCT_Planning>)。

计划值 class int[] 既不是不可变的，也没有 @PlanningId，所以它不能轻易地将它变基到另一个线程（尽管理论上它可以复制它，它目前不这样做）。错误信息可能会更好。

解决方法：将 int[] 包装在计划值 class 中。

多线程时OptaPlanner报错（无法查找外部对象）

Error in OptaPlanner when multithreading (External object cannot be looked up)

optaplanner