从Java地图列表删除元素 [英] Java removing elements from List of maps

问题描述

我的Java 的ArrayList＆LT;地图＆LT;弦乐，对象＆gt;＆GT; 。什么情况下可以从中删除列表中的元素如下：

I have Java ArrayList<Map<String, Object>>. Is it okay to remove elements from that list as follows:

    for (Map<String, Object> anObject : manyObjects) {
        if (anObject.get("x").equals("y")) {
            manyObjects.remove(anObject);
        }
    }

这有什么根本性的错误，这种方法？

Is there anything fundamentally wrong with this approach?

推荐答案

您无法从列表在遍历它与增强的for循环删除元素，因为它会抛出一个CuncurrentModificationException。你可以使用一个明确的迭代器，而非：

You can't removes elements from a List while iterating over it with the enhanced for loop, since it will throw a CuncurrentModificationException. You can use an explicit iterator instead :

Iterator<Map<String, Object>> iter = manyObjects.iterator();
while (iter.hasNext()) {
    Map<String, Object> anObject = iter.next();
    if (anObject.get("x").equals("y")) {
        iter.remove();
    }
}

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