Question

问题：

在示例中 - CloudBalancing，为什么此应用程序无法访问solver.getBestSolution()？该应用程序始终在solver.solve(unsolvedCloudBalance);运行。

有什么建议吗？

此处的一些可行解决方案是在solver.solve(unsolvedCloudBalance);完成，然后获取solver.getBestSolution()？

/*
 * Copyright 2012 JBoss Inc
 *
......
 */

......

public class CloudBalancingHelloWorld {

    public static void main(String[] args) {
        // Build the Solver
        SolverFactory solverFactory = SolverFactory.createFromXmlResource(
            "org/optaplanner/examples/cloudbalancing/solver/cloudBalancingSolverConfig.xml");
        Solver solver = solverFactory.buildSolver();

        // Load a problem with 2 computers and 6 processes
        CloudBalance unsolvedCloudBalance = new CloudBalancingGenerator().createCloudBalance(2, 6);

        // Solve the problem
        System.out.println("Test - solver - before");
        solver.solve(unsolvedCloudBalance);
        System.out.println("Test - solver - after");

        // Display the result
        CloudBalance solvedCloudBalance = (CloudBalance) solver.getBestSolution();
        System.out.println("\nSolved cloudBalance with 2 computers and 6 processes:\n"
            + toDisplayString(solvedCloudBalance));
    }

    public static String toDisplayString(CloudBalance cloudBalance) {
        StringBuilder displayString = new StringBuilder();
        for (CloudProcess process : cloudBalance.getProcessList()) {
            CloudComputer computer = process.getComputer();
            displayString.append("  ").append(process.getLabel()).append(" -> ")
                .append(computer == null ? null : computer.getLabel()).append("\n");
        }
        return displayString.toString();
    }

}

Answer 1

我假设您没有编辑示例的Solver配置XML文件。

如果您查看正在加载Solver configuration from的XML文件，则它没有终止子句。基本上，你告诉Solver要永远奔跑。

您可以编辑解算器配置XML文件，让它在给定条件后终止。有关如何执行此操作，请参阅the documentation。

如果您想以编程方式执行此操作，请查看JavaDoc：SolverConfig类的SolverConfig#setTerminationConfig method和TerminationConfig class。加载XML文件后，您需要编辑SolverFactory的SolverConfig：请参阅SolverFactory#getSolverConfig方法。

Answer 2

非常感谢oskopek，按照你的建议解决了这个问题。

您的建议是：

您可以编辑解算器配置XML文件，让它在给定条件后终止。请参阅有关如何执行此操作的文档。

我做的是：

修改cloudBalancingSolverConfig.xml，使用如下的终止。然后应用程序在运行120秒后退出。

<termination>
    <secondsSpentLimit>120</secondsSpentLimit>
</termination>

以下是2台计算机和6个进程的应用程序输出：

09:57:24.791 [main] INFO  o.d.c.k.b.impl.KieRepositoryImpl - KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0-SNAPSHOT]
09:57:24.963 [main] DEBUG o.drools.core.impl.KnowledgeBaseImpl - Starting Engine in PHREAK mode
Test - solver - before
09:57:25.182 [main] INFO  o.o.core.impl.solver.DefaultSolver - Solving started: time spent (110), best score (uninitialized/0hard/0soft), environment mode (REPRODUCIBLE), random (JDK with seed 0).
09:57:25.213 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (0), time spent (141), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@34abdee4 => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.228 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (1), time spent (156), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@1494b84d => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.228 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (2), time spent (156), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@655a5d9c => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.244 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (3), time spent (172), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@1b5bc39d => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.244 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (4), time spent (172), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@bc57b40 => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.260 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (5), time spent (188), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@21362712 => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.260 [main] INFO  o.o.c.i.c.DefaultConstructionHeuristicPhase - Construction Heuristic phase (0) ended: step total (6), time spent (188), best score (0hard/-6000soft).
09:57:25.712 [main] DEBUG o.o.c.i.l.DefaultLocalSearchPhase -     LS step (0), time spent (640), score (0hard/-8000soft),     best score (0hard/-6000soft), accepted/selected move count (1000/1000), picked move ([com.optaplanner.cloudbalancing.domain.CloudProcess@2575f671, com.optaplanner.cloudbalancing.domain.CloudProcess@72bca894, com.optaplanner.cloudbalancing.domain.CloudProcess@503d56b5, com.optaplanner.cloudbalancing.domain.CloudProcess@433ffad1, com.optaplanner.cloudbalancing.domain.CloudProcess@1fc793c2, com.optaplanner.cloudbalancing.domain.CloudProcess@324dcd31] => com.optaplanner.cloudbalancing.domain.CloudComputer@758f4f03).
09:59:25.083 [main] DEBUG o.o.c.i.l.DefaultLocalSearchPhase -     LS step (1), time spent (120011), score (0hard/-6000soft),     best score (0hard/-6000soft), accepted/selected move count (0/10162968), picked move ([com.optaplanner.cloudbalancing.domain.CloudProcess@503d56b5, com.optaplanner.cloudbalancing.domain.CloudProcess@72bca894, com.optaplanner.cloudbalancing.domain.CloudProcess@324dcd31, com.optaplanner.cloudbalancing.domain.CloudProcess@433ffad1, com.optaplanner.cloudbalancing.domain.CloudProcess@2575f671, com.optaplanner.cloudbalancing.domain.CloudProcess@1fc793c2] => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:59:25.083 [main] INFO  o.o.c.i.l.DefaultLocalSearchPhase - Local Search phase (1) ended: step total (2), time spent (120011), best score (0hard/-6000soft).
09:59:25.083 [main] INFO  o.o.core.impl.solver.DefaultSolver - Solving ended: time spent (120011), best score (0hard/-6000soft), average calculate count per second (84692), environment mode (REPRODUCIBLE).
Test - solver - after

Solved cloudBalance with 2 computers and 6 processes:

OptaPlanner - CloudBalancingHelloWorld.java - 无法访问solver.getBestSolution（）？

2 个答案: