线程“主”中的异常java.lang.IllegalArgumentException：对于随机运行，绑定必须为正

Question

我在以下问题的代码中遇到了麻烦：Exception in thread "main" java.lang.IllegalArgumentException: bound must be positive

您可以看一下代码并提出建议，非常感谢您的帮助。

Exception in thread "main" java.lang.IllegalArgumentException: bound must be positive
    at java.util.Random.nextInt(Random.java:388)
    at vlslsfjs.util.RandomSolutionGenerator.generate(RandomSolutionGenerator.java:41)
    at vlslsfjs.Run.main(Run.java:37)
C:\Users\Administrator\AppData\Local\NetBeans\Cache\8.2\executor-snippets\run.xml:53: Java returned: 1
BUILD FAILED (total time: 0 seconds)

我的代码是

public class RandomSolutionGenerator {

    static public final int FORCE_MIN_SIZE = 1;
    static public final int FORCE_JOB_SIZE = 2;

    public static LS2Solution generate(LS2Problem problem) {
        return generate(problem, -1);
    }

    public static LS2Solution generate(LS2Problem problem, int forceSize) {
        Random r = new Random();
        Map<Integer, Double> opUIdToSublotSize = new HashMap<>();
        Map<Integer, Integer> opUIdToMachId = new HashMap<>();
        List<Integer> pwr = new ArrayList<>();
        int j = 0;
        for (LS2Job job : problem.getJobs()) {
            for (LS2Operation op : job.getOperations()) {
                List<Integer> avMachIds = new ArrayList<>(op.getAvMachineIds());
                int ind = r.nextInt(avMachIds.size());
                opUIdToMachId.put(op.getOpUId(), avMachIds.get(ind));
                double slSize = op.getMinSize()
                        + (op.getMaxSize() - op.getMinSize()) * r.nextDouble();
                if (forceSize == FORCE_MIN_SIZE) {
                    slSize = op.getMinSize();
                } else if (forceSize == FORCE_JOB_SIZE) {
                    slSize = job.getSize();
                }
                opUIdToSublotSize.put(op.getOpUId(), slSize);
            }
            for (int i = 0; i < job.getOperations().size(); ++i) {
                pwr.add(j);
            }
            j++;
        }
        Collections.shuffle(pwr);

        Map<Integer, List<Integer>> machIdToOpUIds = new HashMap<>();
        int[] jobIndToOpInd = new int[problem.getJobs().size()];
        for (int jobInd : pwr) {
            int opInd = jobIndToOpInd[jobInd]++;
            LS2Job job = problem.getJobs().get(jobInd);
            LS2Operation op = job.getOperations().get(opInd);
            int opUId = op.getOpUId();
            int n = (int) Math.ceil(1.0 * job.getSize() / opUIdToSublotSize.get(op.getOpUId()));
            int machId = opUIdToMachId.get(opUId);
            List<Integer> opUIds = machIdToOpUIds.get(machId);
            if (opUIds == null) {
                opUIds = new ArrayList<>();
                machIdToOpUIds.put(machId, opUIds);
            }
            for (int i = 0; i < n; ++i) {
                opUIds.add(opUId);
            }
        }

        return new LS2Solution(opUIdToSublotSize, machIdToOpUIds);
    }
}