"java.util.ConcurrentModificationException" while removing some objects from a list

Question

I need to delete some objects from a list if they meet a condition.

But I am getting java.util.ConcurrentModificationException.

Here is my code:

collegeList.addAll(CollegeManager.findByCollegeID(stateCode, districtCode));

for(College clg:collegeList){
    if(!clg.approve()){
        collegeList.remove(clg);
    }
}

@ruchi Just take some time and effort to search SO before you post such questions. There are plenty of good answers to that on SO already - For e.g. - [here](http://stackoverflow.com/questions/223918/efficient-equivalent-for-removing-elements-while-iterating-the-collection?rq=1) — rtindru, Jun 28 '13 at 05:48

score 10 · Accepted Answer · answered Jun 28 '13 at 05:45

You can't remove elements while iterating through them in that manner. Use an Iterator instead.

Iterator<College> iter = collegeList.iterator();
while(iter.hasNext()) {
    College clg = iter.next();
    if(!clg.approve()) {
        iter.remove();
    }
}

score 0 · Answer 2 · answered Jun 28 '13 at 05:47

0

You need to use an Iterator to iterate through List and remove objects using Iterator#remove().

answered Jun 28 '13 at 05:47

AllTooSir

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"java.util.ConcurrentModificationException" while removing some objects from a list

2 Answers2