大神們　幫忙看下這個數組越界異常．．．

public class Example implements EntryPoint {

AbsolutePanel absolutePanel =new AbsolutePanel();
Button reset = new Button("Reset");
Button[][] buttons = new Button[20][20];
Grid grid = new Grid();

public Example(){
    absolutePanel.setSize("400","400");
    absolutePanel.add(reset);

    grid = new Grid(20,20);

    for (int i = 0; i < buttons.length; i++) {
        for (int j = 0; j < buttons.length; j++) {
            buttons[i][j] = new Button();
            grid.setWidget(20,20,buttons[i][j]);

        }

    }
 absolutePanel.add(grid);
}

public void onModuleLoad() {

// startGame(9,9,10);
RootPanel.get().add(absolutePanel);

｝

Button[][] buttons = new Button[20][20];
这样buttons.length=400，你for循环中肯定越界了

如何　修改呀　我要做一個　掃雷的遊戲．．　應該怎麼改呢　謝謝你了

第二个for循环使用for (int j = 0; j < buttons[i].length; j++) {

private static final int BTN_COLS = 20;
private static final int BTN_ROWS = 20;

Button[][] buttons = new Button[BTN_ROWS][BTN_COLS];
...
    for (int i = 0; i < BTN_ROWS; i++) {
        for (int j = 0; j < BTN_COLS; j++) {