java.util.ConcurrentModificationException 问题

你是用的迭代器吗？
如果是的话，可以看下sun网站上关于treeset的描述
The Iterators returned by this class's iterator method are fail-fast: if the set is modified at any time after the iterator is created, in any way except through the iterator's own remove method, the iterator will throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future.