java - Java Set中的并发修改异常

Question

作为我程序的一部分，我坚持并发修改异常。这是提到的部分:

PriorityQueue<Customer> marginalGainHeap = new PriorityQueue<Customer>(
            1, new Comparator<Customer>() {
                public int compare(Customer c1, Customer c2) {
                    return Double.compare(c1.getMarginalGain(),
                            c2.getMarginalGain());
                }
            });

    // set of all remains available nodes
    availableNodes.removeAll(churnNet);
    for (Customer avail : availableNodes) {
        avail.setMarginalGain(0);
        marginalGainHeap.add(avail);
    }
    while (seedSet.size() <= budget) {
        **for (Customer remainingNode : availableNodes) {**

            remainingNode.setMarginalGain(calculateMarginalGain(
                    remainingNode, seedSet, network, availableNodes,
                    churnNet));

            marginalGainHeap.remove(remainingNode);
            marginalGainHeap.add(remainingNode);
        }
        seedSet.add(marginalGainHeap.poll());
    }

这里是 calculateMarginalGain 方法:

private int calculateMarginalGain(Customer remainingNode,
            HashSet<Customer> seedSet,
            DirectedSparseGraph<Customer, Transaction> net,
            Set<Customer> availableNodes, HashSet<Customer> churnNetwork) {
        // Marginal gain for short-term campaign
        HashSet<Customer> tmp = new HashSet<Customer>(); // seedset U
                                                            // {remainingNode}
        tmp.add(remainingNode);
        Set<Customer> tmpAvailableNodes = availableNodes;
        HashSet<Customer> NeighborOfChurn = getNeighbors(churnNetwork, net);
        // sigma function for calculating the expected number of influenced
        // customers- seedSettmp=seedset U {u}
        tmpAvailableNodes.removeAll(NeighborOfChurn);
        Set<Customer> influencedNet = getNeighbors(tmp, net);
        tmpAvailableNodes.retainAll(influencedNet);
        return tmpAvailableNodes.size();
    }

我在用 ** 指定的程序行中遇到了这个异常。我发现这个错误可能是由迭代器引起的。但是我一个都没用!请帮我找出导致该异常的原因以及我该如何解决？

问候。

Answer 1

将您的设置转换为数组可能会解决您的问题

例子:

Set<String> set = new Set<String>(size);
String[] array = set.toArray(new String[set.size()]);

所以在你的 for 循环中你可以做类似的事情:

for(String foo : set.toArray(new String[notis.size()])) {
    // Loop stuff here
}