Question: I am writing a chess library in Java and focusing on the Object-Oriented design of it. I idea is to create a class called Tile, which contains a coordinate (x, y), boolean isOccupied, and the information of the piece that it contains. 

It looks like this:

```
public abstract class Tile {

    boolean isOccupied;
    int x, y;
    Piece piece;

    Tile(boolean isOccupied, int x, int y, Piece piece) {

        this.isOccupied = isOccupied;
        this.x = x;
        this.y = y;
        this.piece = piece;

    }

    //Returns the piece on the tile - will be implemented in the subclass
    public abstract Piece getPiece();

    //Places a piece on the tile - will be implemented in the subclass
    public abstract void placePiece(Piece piece);

    public abstract void removePiece();

}

```

Then, on my Piece class, I am trying to make a method that checks whether the destination of the piece is a valid location. The function declaration might look something like:

```
public abstract boolean isValidLocation(Tile[][] board, int fromX, int fromY, int toX, int toY);

```

I am expecting to create a 2D-array of a class Tile named board and set the starting coordinate and the ending coordinate and do the calculation on each Piece subclass to see if the target location is valid.

My questions are:

1) Is it possible to create a 2D array of a class (Tile) like this and make it work as I expect? 

2) Will I have to add a function that generates a 'n x n' Tile array anywhere in my classes?

3) Will there be a simpler way to do this?

Answer: 
Deleting all the files related to old build did the trick for me
are the .metadata files and .xsp-config files for the custom controls present in the on disk project?

e.g for 1 custom control there should be three files

```
mycustomcontrol.xsp
mycustomcontrol.xsp-config
mycustomcontrol.metadata

```

also what do you mean by 'missing' do you mean that you cannot see them in the list of custom controls? or do you mean that they are imported and you can see them in the NSF but they do not build properly, and therefore you see an errors within XPages about not being able to use them?

is there anything in common about the controls that are missing and the controls that are successful?