Question

I cant get this to compile in java idk if im making the wrong file or what but this si the code I was given I would like stsep by step java instuctions and which compiler to use to execute this code

• import java.awt.BorderLayout;
  import java.awt.Color;
  import java.awt.Dimension;
  import java.awt.Font;
  import java.awt.FontMetrics;
  import java.awt.Graphics;
  import java.awt.Graphics2D;
  import java.awt.RenderingHints;
  import java.awt.event.MouseAdapter;
  import java.awt.event.MouseEvent;
  import java.util.Random;

  import javax.swing.JFrame;
  import javax.swing.JPanel;
  import javax.swing.SwingUtilities;

  // We are going to create a Game of 15 Puzzle with Java 8 and Swing
  // If you have some questions, feel free to ue comments ;)
  public class GameOfFifteen extends JPanel { // our grid will be drawn in a dedicated Panel
    
  // Size of our Game of Fifteen instance
  private int size;
  // Number of tiles
  private int nbTiles;
  // Grid UI Dimension
  private int dimension;
  // Foreground Color
  private static final Color FOREGROUND_COLOR = new Color(239, 83, 80); // we use arbitrary color
  // Random object to shuffle tiles
  private static final Random RANDOM = new Random();
  // Storing the tiles in a 1D Array of integers
  private int[] tiles;
  // Size of tile on UI
  private int tileSize;
  // Position of the blank tile
  private int blankPos;
  // Margin for the grid on the frame
  private int margin;
  // Grid UI Size
  private int gridSize;
  private boolean gameOver; // true if game over, false otherwise
    
  public GameOfFifteen(int size, int dim, int mar) {
  this.size = size;
  dimension = dim;
  margin = mar;
    
  // init tiles
  nbTiles = size * size - 1; // -1 because we don't count blank tile
  tiles = new int[size * size];
    
  // calculate grid size and tile size
  gridSize = (dim - 2 * margin);
  tileSize = gridSize / size;
    
  setPreferredSize(new Dimension(dimension, dimension + margin));
  setBackground(Color.WHITE);
  setForeground(FOREGROUND_COLOR);
  setFont(new Font("SansSerif", Font.BOLD, 60));
    
  gameOver = true;
    
  addMouseListener(new MouseAdapter() {
  @Override
  public void mousePressed(MouseEvent e) {
  // used to let users to interact on the grid by clicking
  // it's time to implement interaction with users to move tiles to solve the game !
  if (gameOver) {
  newGame();
  } else {
  // get position of the click
  int ex = e.getX() - margin;
  int ey = e.getY() - margin;
    
  // click in the grid ?
  if (ex < 0 || ex > gridSize || ey < 0 || ey > gridSize)
  return;
    
  // get position in the grid
  int c1 = ex / tileSize;
  int r1 = ey / tileSize;
    
  // get position of the blank cell
  int c2 = blankPos % size;
  int r2 = blankPos / size;
    
  // we convert in the 1D coord
  int clickPos = r1 * size + c1;
    
  int dir = 0;
    
  // we search direction for multiple tile moves at once
  if (c1 == c2 && Math.abs(r1 - r2) > 0)
  dir = (r1 - r2) > 0 ? size : -size;
  else if (r1 == r2 && Math.abs(c1 - c2) > 0)
  dir = (c1 - c2) > 0 ? 1 : -1;
    
  if (dir != 0) {
  // we move tiles in the direction
  do {
  int newBlankPos = blankPos + dir;
  tiles[blankPos] = tiles[newBlankPos];
  blankPos = newBlankPos;
  } while(blankPos != clickPos);
    
  tiles[blankPos] = 0;
  }
    
  // we check if game is solved
  gameOver = isSolved();
  }
    
  // we repaint panel
  repaint();
  }
  });
    
  newGame();
  }
    
  private void newGame() {
  do {
  reset(); // reset in intial state
  shuffle(); // shuffle
  } while(!isSolvable()); // make it until grid be solvable
    
  gameOver = false;
  }
    
  private void reset() {
  for (int i = 0; i < tiles.length; i++) {
  tiles[i] = (i + 1) % tiles.length;
  }
    
  // we set blank cell at the last
  blankPos = tiles.length - 1;
  }
    
  private void shuffle() {
  // don't include the blank tile in the shuffle, leave in the solved position
  int n = nbTiles;
    
  while (n > 1) {
  int r = RANDOM.nextInt(n--);
  int tmp = tiles[r];
  tiles[r] = tiles[n];
  tiles[n] = tmp;
  }
  }
    
  // Only half permutations o the puzzle are solvable
  // Whenever a tile is preceded by a tile with higher value it counts
  // as an inversion. In our case, with the blank tile in the solved position,
  // the number of inversions must be even for the puzzle to be solvable
  private boolean isSolvable() {
  int countInversions = 0;
    
  for (int i = 0; i < nbTiles; i++) {
  for (int j = 0; j < i; j++) {
  if (tiles[j] > tiles[i])
  countInversions++;
  }
  }
    
  return countInversions % 2 == 0;
  }
    
  private boolean isSolved() {
  if (tiles[tiles.length - 1] != 0) // if blank tile is not in the solved position ==> not solved
  return false;
    
  for (int i = nbTiles - 1; i >= 0; i--) {
  if (tiles[i] != i + 1)
  return false;
  }
    
  return true;
  }
    
  private void drawGrid(Graphics2D g) {
  for (int i = 0; i < tiles.length; i++) {
  // we convert 1D coords to 2D coords given the size of the 2D Array
  int r = i / size;
  int c = i % size;
  // we convert in coords on the UI
  int x = margin + c * tileSize;
  int y = margin + r * tileSize;
    
  // check special case for blank tile
  if(tiles[i] == 0) {
  if (gameOver) {
  g.setColor(FOREGROUND_COLOR);
  drawCenteredString(g, "\u2713", x, y);
  }
    
  continue;
  }
    
  // for other tiles
  g.setColor(getForeground());
  g.fillRoundRect(x, y, tileSize, tileSize, 25, 25);
  g.setColor(Color.BLACK);
  g.drawRoundRect(x, y, tileSize, tileSize, 25, 25);
  g.setColor(Color.WHITE);
    
  drawCenteredString(g, String.valueOf(tiles[i]), x , y);
  }
  }
    
  private void drawStartMessage(Graphics2D g) {
  if (gameOver) {
  g.setFont(getFont().deriveFont(Font.BOLD, 18));
  g.setColor(FOREGROUND_COLOR);
  String s = "Click to start new game";
  g.drawString(s, (getWidth() - g.getFontMetrics().stringWidth(s)) / 2,
  getHeight() - margin);
  }
  }
    
  private void drawCenteredString(Graphics2D g, String s, int x, int y) {
  // center string s for the given tile (x,y)
  FontMetrics fm = g.getFontMetrics();
  int asc = fm.getAscent();
  int desc = fm.getDescent();
  g.drawString(s, x + (tileSize - fm.stringWidth(s)) / 2,
  y + (asc + (tileSize - (asc + desc)) / 2));
  }
    
  @Override
  protected void paintComponent(Graphics g) {
  super.paintComponent(g);
  Graphics2D g2D = (Graphics2D) g;
  g2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
  drawGrid(g2D);
  drawStartMessage(g2D);
  }
    
  public static void main(String[] args) {
  SwingUtilities.invokeLater(() -> {
  JFrame frame = new JFrame();
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.setTitle("Game of Fifteen");
  frame.setResizable(false);
  frame.add(new GameOfFifteen(4, 550, 30), BorderLayout.CENTER);
  frame.pack();
  // center on the screen
  frame.setLocationRelativeTo(null);
  frame.setVisible(true);
  });
  }

    
  }

Answer 1

/*

//Note:--> The > JDK 1.8 does not support the command prompt. So you need to use any IDE like Eclipse, IntelliJ idea etc.

or install the old version of jdk like JDK1.8

and follow the steps  

This code is running correctly. So there is no problem with code.

If you haven't install JDK

First of all, install it (Search JDK on search engine)

after the installation gets complete.

if you are using command prompt to run this program

follow the following steps

(1) go to Control Panel

(2) Select the System icon

(3)

Select the Advance system settings

(4)

Now select the environment variables

(5)

Click New in the user variables section.

(6)

the variable value is the path of the directory where your JDK is installed.

By default location is given above in pic.

(7) and press OK.

To check it, Go to the command prompt (type cmd in the search box ) or you can use the run command (Win key +R)

Type javac in cmd .

Now go to the file location where you saved your GameOfFifteen.java file. using CD command

as I have saved it in E:\

//Now use the following commands to compile and run your program

*/

//Output

//If you need any help regarding this solution ............ please leave a comment ........ thanks