Java Swing，ActionListener

Question

I'm writing simple minesweeper game. I used 2 two-dimensional arrays, one is holding JButton and second array whether is bomb inside.

JButton[][] tab = new JButton[8][8];
int[][] mine = new int[8][8];

In ActionLister I'm checking which button is actually clicked and if there is bomb inside.

public void actionPerformed(ActionEvent e) {
    if(e.getSource()==tab[0][0] && mine[0][0]==9) {
        tab[0][0].setText("B");
        tab[0][0].setEnabled(false);
    }
    if(e.getSource()==tab[0][1] && mine[0][1]==9) {
        tab[0][1].setText("B");
        tab[0][1].setEnabled(false);
    }
    if(e.getSource()==tab[0][2] && mine[0][2]==9) {
        tab[0][2].setText("B");
        tab[0][2].setEnabled(false);
    }

9 means there is bomb inside.

I wouldn't like to write 64 line of codes like this. How can I change this ?

Answer 1

Since I assume you are using Java 8 (or later), this should be the most simple solution:

//code to create buttons and to place them on the frame / panel
for(int y = 0; y < 8; y++){
    for(int x = 0; x < 8; x++){
        JButton b = new JButton();
        //place the JButton on your frame / panel
        //probably you are using a GridLayout
        b.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                if(mine[y][x] == 9){
                    b.setText("B");
                    b.setEnabled(false);
                }
            }
        });
    }
}

This way you won't have to save all the buttons, because you can access the button variable from inside the ActionListener.

When you are using Java 7 (or earlier), you farther have to declare the button variable as final

final JButton b = new JButton();

Alternatively you can also cast the source to JButton to get access to the source component from inside the action listener

public void actionPerformed(ActionEvent e){
    JButton b = (JButton)e.getSource();
    b.setText("B");
    b.setEnabled(false);
}