Footbal game design in Java

Classes:

public class Player{

/**
Personal Information
*/
protected String _name;
protected String _address;
protected String _bloodGroup;
protected String _age;
protected String _sex;

/**
Game related Information
*/
protected Team _team;
protected Position _position;
protected Vector neighborList;


}


public class ball{
protected Position _position;
protected Player _possesion;

public void kickBall(force x, angle y){

}

public void changePosition(position x, position y){
// move from position x to position y
}

public void drawTrajectory(){

}

public boolean isGoal(){

}

public boolean isValidGoal(){

}

public void pass(Player x, Player Y){

}

}

Think more on the API's of this game.