java嵌套循环在运行时创建重复项,找不到问题?
当代码运行时,嵌套循环会导致它偶尔为系统创建重复条目,我花了一段时间查看了这一点,但仍然找不到导致这一点的原因,非常感谢您的帮助
for(int i = 0; i < subWorkItemElement.getChildNodes().getLength(); i++) {
Boolean test = false;
WorkItemCommon existingChild = null;
String summary = null;
if(subWorkItemElement.getChildNodes().item(i).getNodeName().equals("workitem")) {
// We know it's a work item - but is it in the existing list?
Element childWorkItem = (Element) subWorkItemElement.getChildNodes().item(i);
for(int j = 0; j < subWorkItemElement.getChildNodes().getLength(); j++) {
if(childWorkItem.getChildNodes().item(j) instanceof Element) {
if(((Element)childWorkItem.getChildNodes().item(j)).getNodeName().equals("details")) {
summary = ((Element) childWorkItem.getChildNodes().item(j)).getElementsByTagName("summary")
.item(0).getTextContent();
for(String k : userInfoHashMap.keySet()) {
summary = summary.replace("${" + k + "}", userInfoHashMap.get(k));
}
if(childHashTable.containsKey(summary)) {
test = true;
existingChild = childHashTable.get(summary);
IWorkItem workItem = existingChild.getWorkItem();
System.out.println("INFO: The task with summary \"" + summary + "\" already exists. Skipping creation.");
System.out.println("this task is work item: " + workItem.getId());
//either check the tasks in the xml for updated details and then modify the existing workitem
//or just modify the work item without checking for updates
makeChildTask(childWorkItem, existingChild, childHashTable, userInfoHashMap, workItemHashMap, rtc, false);
break;
}
}
}
}
if(!test) {
System.out.println("INFO: The task with summary " + summary + " does not currently exist. Creating.");
makeChildTask(childWorkItem, thisItem, childHashTable, userInfoHashMap, workItemHashMap, rtc, true);
} else makeFromExistingChildTask(childWorkItem, existingChild, userInfoHashMap, workItemHashMap, rtc);
}
}
# 1 楼答案
您可能(不确定
makeChildTask()
在遍历子列表时更改了XML结构。虽然不一定不正确,但这可能意味着在处理列表时插入了条目。由于每次调用subWorkItemElement.getChildNodes().getLength()
而不是缓存它,这可能会导致循环迭代之间的长度发生变化