Colonies GAME OF LIFE CLASS

package gameoflife;

import java.util.*;

public class Colonies {

    private String name;

    private Set<Coor> cells = new HashSet();

    public Colonies(java.lang.String name) {
        colonyNumber= getNextColonyNumber();
        this.name = name;
    }
    private int colonyNumber;
private static int nextColonyNumber= 0;
    public static int getNextColonyNumber(){

        return nextColonyNumber++;
    }


    public int getColonyNumber(){
        return colonyNumber;
    }

    public java.lang.String getColonyName() {
        return name;
    }
    private int gennumb = 0;

    public int getGenerationNumber() {


        return gennumb;
    }

    public void setCellAlive(int x, int y) {
        Coor c = new Coor(x, y);
        cells.add(c);
    }

    public void setCellDead(int x, int y) {
        Coor c = new Coor(x, y);
        cells.remove(c);
    }

    public void resetColony() {
        cells.clear();

    }

    public int getNumberCells() {
         return cellse.size();
    }

    public boolean isCellAlive(int x, int y) {
        Coor c = new Coor(x, y);
        return cells.contains(c);

    }
    private Set<Coor> cellse = new HashSet();
    private Set<Coor> nextgenCell = new HashSet();

    public void evolve() {
        gennumb++;
        cellse.clear();
        nextgenCell.clear();
        for (Coor c : cells) {
            Coor a = new Coor(c.x - 1, c.y - 1);
            Coor b = new Coor(c.x + 1, c.y + 1);
            Coor t = new Coor(c.x + 1, c.y - 1);
            Coor d = new Coor(c.x - 1, c.y + 1);
            Coor e = new Coor(c.x + 1, c.y + 0);
            Coor f = new Coor(c.x - 1, c.y + 0);
            Coor g = new Coor(c.x + 0, c.y - 1);
            Coor h = new Coor(c.x + 0, c.y + 1);
            Coor i = new Coor(c.x + 0, c.y + 0);
            cellse.add(a);
            cellse.add(b);
            cellse.add(t);
            cellse.add(d);
            cellse.add(e);
            cellse.add(f);
            cellse.add(g);
            cellse.add(h);
            cellse.add(i);
        }
        for (Coor c : cellse) {
            int counter = 0;
            if (isCellAlive(c.x - 1, c.y - 1)) {
                counter++;
            }
            if (isCellAlive(c.x + 1, c.y + 1)) {
                counter++;
            }
            if (isCellAlive(c.x + 1, c.y - 1)) {
                counter++;
            }
            if (isCellAlive(c.x - 1, c.y + 1)) {
                counter++;
            }
            if (isCellAlive(c.x + 1, c.y + 0)) {
                counter++;
            }
            if (isCellAlive(c.x - 1, c.y + 0)) {
                counter++;
            }
            if (isCellAlive(c.x + 0, c.y - 1)) {
                counter++;
            }
            if (isCellAlive(c.x + 0, c.y + 1)) {
                counter++;
            }
            if (isCellAlive(c.x, c.y)) {
                if (counter == 3) {
                    nextgenCell.add(c);
                }
                if (counter == 2) {
                    nextgenCell.add(c);
                }

            } else {
                if (counter == 3) {
                    nextgenCell.add(c);
                }

            }

        }
        cells.clear();
        for (Coor c : nextgenCell) {
            cells.add(c);
        }
    }

    @Override
    public java.lang.String toString() {
        return singleRow(20, 20) + "generation number: " + gennumb;

    }

    public String helperXAndY(int x, int y) {
        if (isCellAlive(x, y)) {
            return "*";
        } else {
            return " ";

        }

    }

    public String singleRow(int xSize, int ySize) {
        String b = " ";
        for (int y = ySize - 1; y >= 0; y--) {
            for (int x = 0; x < xSize; x++) {
                b += (helperXAndY(x, y));
            }
            b += "\n";
        }
        return b;
    }

}