原因：一个线程在用迭代器iterator的同时，另一个线程又在修改list数据
一种解决办法是
synchronize all access to the List, using the list itself as the monitor
code:
synchronized (list) { for (Iterator it = list.iterator(); it.hashNext(); ) { Foo f = (Foo) it.next(); // do what you need with f }}
Whatever other threads are modifying the list, they need to be synchronized too, also on the list. E.g.:
code:
syncronized (list) { list.add(new Foo());}
or
code:
syncronized (list) { list.remove(oldFoo);}
责任编辑：小草
