The following is a Minesweeper square class with GUI components.

/**
 * Represents a single square in Minesweeper.
 * 
 * @author J. Chung
 * @version CS-501B
 */

// GUI imports:
import javax.swing.*;

public class MineSquare
{
    // Fields:
    private  String  _shown;      // What a square is showing now
    private  boolean _mined;      // Square is mined or not
    private  boolean _flagged;    // Square is flagged or not
    private  boolean _questioned; // Square is question marked or not
    private  int     _minecount;  // Square's surrounding mine count
    private  boolean _opened;     // Player has opened this square or not
    // GUI fields:
    private  JButton _button; // Use when square not opened; displays " " or "F" (flag)
    private  JLabel  _label;  // Use when square opened; displays " " or _minecount
    

    /**
     * Default constructor
     * 
     * Sets _mined and _opened to false.
     */
    public MineSquare()
    {
        _mined = false;
        _opened = false;
        // GUI initialization:
        _button = new JButton(" ");
        _label = new JLabel(" ");
    }

    
    
    /**
     * Returns flagged status of square.
     * 
     * @return  _flagged    Flagged status
     */
    public boolean isFlagged() {
        return _flagged;
    }

    /**
     * Sets or unsets flag on a square.
     * 
     * @param   _flagged    True or false (square is flagged or not)
     */
    public void setFlagged(boolean _flagged) {
        this._flagged = _flagged;
        
        // If flagged, square should show "F":
        if ( isFlagged() == true )
            setShown("F");
        else
            setShown(" ");            
    }

    public int getMinecount() {
        return _minecount;
    }

    public void setMinecount(int _minecount) {
        this._minecount = _minecount;
    }

    public boolean isMined() {
        return _mined;
    }

    public void setMined(boolean _mined) {
        this._mined = _mined;
    }

    public boolean isOpened() {
        return _opened;
    }

    /**
     * Open a square.
     * (A square can't be unopened.)
     */
    public void setOpened() {
        this._opened = true;
        
        if ( isMined() == true )
            setShown("X");
        else if ( getMinecount() > 0 )
            setShown(_minecount + "");
        else // blank space for _minecount = 0
            setShown(" ");
    }

    public boolean isQuestioned() {
        return _questioned;
    }

    public void setQuestioned(boolean _questioned) {
        this._questioned = _questioned;
    }

    public String getShown() {
        return _shown;
    }

    public void setShown(String _shown) {
        this._shown = _shown;
    }

    
    
    
    // GUI methods:
    /**
     * Return the "face" of the MineSquare.
     * 
     * @return  _button if unopened or _label if opened
     */
    public JButton getFace()
    {
        return _button;
    }
    
    
    

}