mongodb AggregationOutput list.iterator() 无限循环的问题

来源：互联网发布：优化驱动器多少遍编辑：程序博客网时间：2024/06/01 08:50

在mongodb中将获取到的聚集进行遍历的时候进入无限循环，代码：

@Overridepublic Object getLogwayList() {Iterable<DBObject> list= pageAnaDao.getLogwayList().results();while(list.iterator().hasNext()){    DBObject result = list.iterator().next();    String id = result.get("_id").toString();    Iterable<DBObject> listCount = (Iterable<DBObject>) result.get("counts");while(listCount.iterator().hasNext()){    DBObject resultOne = listCount.iterator().next();}}}

下边这句代码始终为真：

list.iterator().hasNext()

而下边这句一直返回到第一个元素：

DBObject result = list.iterator().next();

所以导致的结果就是不断遍历第一个元素，进入无限循环。正确的方式：

@Overridepublic Object getLogwayList() {Iterable<DBObject> list= pageAnaDao.getLogwayList().results();Iterator<DBObject> iterator= list.iterator();List<LogWay> results = new ArrayList<LogWay>();while(iterator.hasNext()){    DBObject result = iterator.next();    String id = result.get("_id").toString();    Iterable<DBObject> listCount = (Iterable<DBObject>) result.get("counts");    Iterator<DBObject> iteratorCount= listCount.iterator();while(iteratorCount.hasNext()){    DBObject resultOne = iteratorCount.next();}}

或者采用foreach()循环，进行:

for (DBObject obj : output.results()) {String id = obj.get("_id");int times = Integer.parseInt(obj.get("times").toString());System.out.println("ID IS "+id+" time: "+times);}

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