android – 在onRestoreInstanceState中发生ClassCastException

ClassCastException随机发生以恢复onRestoreInstanceState()中的Vector.
通常恢复向量很好,但有时会发生异常.

我认为它发生在活动进入后台并被破坏但我不确定.

有任何想法吗？谢谢.

Stack<LocationInfo> mLocationInfoVector;

@Override
protected void onSaveInstanceState(Bundle outState) {
    outState.putSerializable("locationInfos",mLocationInfoVector);

    super.onSaveInstanceState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    if (savedInstanceState.getSerializable("locationInfos") != null) {
        @SuppressWarnings("unchecked")
        mLocationInfoVector= (Stack<LocationInfo>) savedInstanceState.getSerializable("locationInfos");
    }

    super.onRestoreInstanceState(savedInstanceState);
}

添加：

我忘了附上异常日志.
那是

java.lang.classCastException: java.util.ArrayList cannot be cast to java.util.Stack

解决方法

我使用下一个代码来恢复Vector：

objects = new Vector<Object>((Collection<Object>) state.getSerializable(EXTRA_OBJECTS));

它会阻止java.lang.classCastException并保存元素顺序.

要恢复Stack,您可以使用下一个代码：

stack = new Stack<Object>();
stack.addAll((Collection<Object>) state.getSerializable(EXTRA_STACK));

它的工作原理是Vector,Stack,ArrayList都在扩展Collection,你可以将你的序列化对象转换为Collection并传递给Stack或Vector addAll()方法.