在 Arraylist.iterator().next() 上获取 Concurrent

Question

我有以下代码，它是较长代码段的一部分，旨在将对象图转换为平面树，以便现有代码可以进一步处理该树：

private void addProjectStreamsFromGraphToTree(String parentIndex, Map<String, Object> objectTree, ProjectTreeView projectTreeView) {

        Set<Integer> allConnectedLevelOids = new HashSet<Integer>();

        // Set in the tree + add everything underneath projectStream:

        int index = 1;

        String treeIndex ="";

        for (Iterator<ExportableProjectStreamView> iter = projectTreeView.getProjectStreamList().iterator(); iter.hasNext(); index++) {

            // Getting the concurrentModificationException on the below line

            ProjectStreamView projectStreamView = (ProjectStreamView) iter.next();

            treeIndex = parentIndex + "." + index;

            objectTree.put(treeIndex, projectStreamView);

            addLifeCyclesFromGraphToTree(allConnectedLevelOids, projectStreamView , treeIndex, objectTree, projectTreeView);

        }

    }

private void addLifeCyclesFromGraphToTree(Set<Integer> allConnectedLevelOids, ProjectStreamView projectStreamView, String parentIndex, Map<String, Object> objectTree, ProjectTreeView projectTreeView) {

    int index = 1;

    String treeIndex ="";

    ExportableLifecycleView lifecycleView = projectTreeView.getLifecycleList().stream().filter(lcv -> projectStreamView.getLifecycleOid().equals(lcv.getOid())).findFirst().get();

    treeIndex = parentIndex + "." + index;

    objectTree.put(treeIndex, lifecycleView);

    // add the levels that are linked to this lifecycle and at once add all oids of the levels,

    // connected to this lifecycle, to the allconnectedLevelOids.       

    allConnectedLevelOids.addAll(addConnectedLevelsFromGraphToTree(lifecycleView, treeIndex, objectTree, projectTreeView));

}

如您所见，除了获取迭代器外，我从不与 projectTreeView.getProjectStreamList() 交互，而且我从不在任何列表上调用 .remove() 或 .add()。我所做的唯一改变事物的事情是树图上的 put() 和本地 HashSet() 上的 .add。我也不以任何方式更改原始 projectTreeView，并且我只读取使用迭代器检索的 projectStreamView 的属性。

Answer 1

我做了一些检查，我发现了是什么原因造成的。原来是里面有bug&nbsp;projectTreeView.getLevelList()。我在使用 返回之前对我的列表进行排序Collections.sort()，而不是levelList在那里排序，我排序projectStreamList......