Question

我正在尝试获取List的大小但是在执行此操作时，我在size（）方法上遇到了ConcurrentModificationException。这很奇怪，因为我不是在迭代它时尝试修改列表。这是我的一些代码可能导致它但我无法看到它的问题。

主要方法：

private void setupCharacterGrid() {

    currentCharacters.add(0, new Character("add", "add"));
    if (currentCharacters.size() < 9) {
        sub(0, currentCharacters.size(), currentCharacters.size());
    } else {
        sub(0, 9, 9);
    }

    fillGrids();

    charPager.setAdapter(new CustomPagerAdapter(characterGrids));
    charPager.setCurrentItem(0);

}

子方法（填充列表的方法）请注意，divideCharList的类型为：List＆gt;其中Character是自定义POJO。

private void sub(int start, int end, int n) {
    int size = currentCharacters.size();
    if (start > size) {
        return;
    } else if (start == size) {
        // new list(currentcharacters.get(start))
        // check if it fits on the previous grid
        List<Character> lastGrid = dividedCharList.get(dividedCharList
                .size() - 1);
        if (lastGrid.size() < 9) {
            lastGrid.add(currentCharacters.get(start - 1));
        } else {
            List<Character> finalCharList = new ArrayList<Character>();
            finalCharList.add(currentCharacters.get(start - 1));
            dividedCharList.add(finalCharList);
        }
        return;
    } else {
        if (size < start + n) {
            sub(start, end, n--);
        } else {
            // new list(currentcharacters.sublist(start, end);
            // end = end + n;
            // start = end + 1
            dividedCharList.add(currentCharacters.subList(start, end));
            start = end + 1;
            end = end + n;
            sub(start, end, n);
        }
    }
}

尝试获取大小时发生异常的方法：

private synchronized void fillGrids() {
    for (int i = 0; i < dividedCharList.size(); i++) {
        GridView gridView = new GridView(this);
        gridView.setNumColumns(3);
        CharacterGridAdapter aa = new CharacterGridAdapter(this,
                R.layout.charactergrid_cell, dividedCharList.get(i));
        gridView.setAdapter(aa);
        characterGrids.add(gridView);
    }
}

请注意，当我尝试通过列表迭代并尝试获取值并将其显示在日志

时，也会发生异常

修改

我刚刚注意到调用gridView.setAdapter（）时发生异常，ArrayAdapter的getCount方法抛出ConcurrentModificationException

EDIT2

这是堆栈跟踪，它可能会有所帮助：

01-24 13:03:44.942: E/AndroidRuntime(15336): FATAL EXCEPTION: main
01-24 13:03:44.942: E/AndroidRuntime(15336): java.util.ConcurrentModificationException
01-24 13:03:44.942: E/AndroidRuntime(15336): at                 java.util.AbstractList$SubAbstractList.size(AbstractList.java:360)
 01-24 13:03:44.942: E/AndroidRuntime(15336):   at    android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330)
 01-24 13:03:44.942: E/AndroidRuntime(15336):   at android.widget.GridView.setAdapter(GridView.java:182)
 01-24 13:03:44.942: E/AndroidRuntime(15336):   at xx.ProfileActivity.fillGrids(ProfileActivity.java:111)
 01-24 13:03:44.942: E/AndroidRuntime(15336): 
 xx.ProfileActivity.setupCharacterGrid(ProfileActivity.java:96)
 01-24 13:03:44.942: E/AndroidRuntime(15336):   at xx.ProfileActivity.access$6(ProfileActivity.java:87)

根据要求提供适配器代码

public class CharacterGridAdapter extends ArrayAdapter<Character> {

private Context context;
private List<Character> objects;
private int resource;

public CharacterGridAdapter(Context context, int resource, List<Character> listChar) {
    super(context, resource);
    this.context = context;
    this.objects = listChar;
    this.resource = resource;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View rowView = convertView;
    if (rowView == null) {
        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        rowView = inflater.inflate(R.layout.charactergrid_cell, null);
    } else {
    }
    return rowView;
}

}

任何可以帮我解决这个问题的人？

Answer 1

删除“已同步”，而不是使用List使用CopyOnWriteArrayList。您可以在这里找到更多信息 CopyOnWriteArrayList

请求列表大小时的并发修改

1 个答案: