Question: I made this code:

```
protected Lala lala;
private Oyeha oyeha;

public void setLala(Lala lala) {
    this.lala = lala;
}

this.oyeha = (Oyeha) this.lala;
            executeHostBean = this.oyeha.updateMethod(a, b, c, d, e);

```

Lala is the parrent class.

Oyeha is the child which extends Lala.

But when i run this code, i got error:

> 
> java.lang.ClassCastException: $Proxy201
> 
> 
> 

I can't find where my mistake is.
Can somebody help me solve this problem, please? 
Thank you. :)

Answer: 
What you'll need is a ListView. A ListView is a view that orders its child views in a scrolling vertical list automatically depending on the elements present in the dataset observed by the Adapter given to it. Essentially, there are three parts:

1. The dataset that contains the data you want to display.
2. The Adapter which provides an interface from that data to:
3. The view itself, which is responsible for displaying the data.

What you need to define is a mapping from some sort of collection to the Adapter so that the adapter knows how to access the data it needs to give to the ListView. There are examples of this in the Android SDK and there's even a [ListView Tutorial](http://developer.android.com/guide/topics/ui/layout/listview.html).

Beyond that, there are two approaches to presenting your data in the ListView. You can compute the string `"DateX | Num1 | Num2 | CalculatedNumX"` and simply have each list element be that string (simplest). Or, you can create a custom view with 4 (or 7) text boxes and populate each one individually with the appropriate data. This is more complex but has the advantage of providing more flexibility as to how you format and position your text.
Write your own Custom Adapter. You will create your own layout, in which you can set any kind of an item which is created based on your own custom layout. Check out the following [link](http://www.softwarepassion.com/android-series-custom-listview-items-and-adapters/).It will definitely help you.

You can add your calculation once you are done with the basic ListView Adapters. For adding a layout at the top, One way of doing is to use a function called `adapt.insert(object, index)` where you basically provide an index of where to add an item. As an example, the link given above have a method called `getOrders()`.