java - 如果 Arraylist 中存在元素而不引发 ConcurrentModificationException，则从 Arraylist 中移除这些元素

Question

代码如下:

Ledger obj = null;
MyUtilPojo obj1 = null;
Iterator it = toList.iterator();
while (it.hasNext()) {
    obj = (Ledger) it.next(); //after first iteration next here produce an error
    Iterator it1 = moreToList.iterator();
    while (it1.hasNext()) {
        obj1 = (MyUtilPojo) it1.next();
        if (obj.getId() == obj1.getKey()) {
            toList.remove(obj);                                
        }
    }
}

这会引发错误 ConcurrentModificationException，有人可以帮忙吗？

Answer 1

类似的东西应该可以工作(在临时列表中为 toList 构建新内容):

final List<Ledger> target = new ArrayList<Ledger>();
for (final Ledger led : toList) {
    for (final MyUtilPojo mup : moreToList) {
        if (led.getId() != mup.getKey()) { // beware of !=
            target.add(led);
        }
    }
}

toList = target;