如何更新列表中的数据 <? extends Map<String,?> &gt;

Question

I'm making use of a List<? extends Map<String,?>> List<? extends Map<String,?>> that I populated with data.

cursor.moveToFirst();
while (cursor.getPosition() < cursor.getCount()) {
    item.put("ProdName",cursor.getString(2));
    item.put("ProdSize", cursor.getString(3));
    item.put("ProdPack",cursor.getString(4));
    item.put("OrdQty","0");

    //list.add(item);
    list.add(i, item);
    item = new HashMap<String,String>();    
    cursor.moveToNext();
    i = i + 1;
}

How do I update a value for example in the OrdQty field?

Answer 1

Looks like a very bad design to me. Java's an object-oriented language. Why don't you provide a real contract and create Product and Order objects? Give Order a List of Products to maintain. What you're proposing is less self-explanatory and harder to write and maintain.

Answer 2

@Duffymo is right, you shouldn't use a map as a pseudo-object.

This is how to update an object at a specific place ( index ) in a list.

Map<String,?> ugly = list.get(index);

Then you can do whatever you want with the object ugly.

If you did it properly, it would look like this...

Product p = list.get(index);
p.setOrderQuantity(17);