Java applet中的越界異常

Question

我一直在嘗試創建一個applet，以便隨機播放一副紙牌並顯示前十張。 在我嘗試添加代碼以防止卡重復使用之前，它一直在工作。 它不斷返回超出范圍的異常。

import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Image;
import java.util.Random;

public class Main extends Applet
{
    Image card1;
    Image card2;
    Image card3;
    Image card4;
    Image card5;
    Image card6;
    Image card7;
    Image card8;
    Image card9;
    Image card10;

    public void init()
    {
        Random random = new Random();
        String cards[][] = {{"c1.gif", "c2.gif", "c3.gif", "c4.gif", "c5.gif", "c6.gif", "c7.gif", "c8.gif", "c9.gif", "c10.gif", "cj.gif", "ck.gif", "cq.gif"}, {"s1.gif", "s2.gif", "s3.gif", "s4.gif", "s5.gif", "s6.gif", "s7.gif", "s8.gif", "s9.gif", "s10.gif", "sj.gif", "sk.gif", "sq.gif"}, {"d1.gif", "d2.gif", "d3.gif", "d4.gif", "d5.gif", "d6.gif", "d7.gif", "d8.gif", "d9.gif", "d10.gif", "dj.gif", "dk.gif", "dq.gif"}, {"h1.gif", "h2.gif", "h3.gif", "h4.gif", "h5.gif", "h6.gif", "h7.gif", "h8.gif", "h9.gif", "h10.gif", "hj.gif", "hk.gif", "hq.gif"}};
        int selectedCard[] = new int[10];
        int selectedSuit[] = new int[10];
        int suit = random.nextInt(4);
        int card = random.nextInt(13);
        boolean newCard = false;

        for(int x = 0; x < 10; x++)
        {
            while(newCard = false)
            {
                newCard = true;
                suit = random.nextInt(4);
                card = random.nextInt(13);

                for(int y = 0; y < x; y++)
                {
                    if(selectedCard[y] == card && selectedSuit[y] == suit)
                    {
                        newCard = false;
                    }
                }
            }

            selectedCard[x] = card;
            selectedSuit[x] = suit;
        }

        card1 = getImage(getDocumentBase(), cards[selectedSuit[1]][selectedCard[1]]);
        card2 = getImage(getDocumentBase(), cards[selectedSuit[2]][selectedCard[2]]);
        card3 = getImage(getDocumentBase(), cards[selectedSuit[3]][selectedCard[3]]);
        card4 = getImage(getDocumentBase(), cards[selectedSuit[4]][selectedCard[4]]);
        card5 = getImage(getDocumentBase(), cards[selectedSuit[5]][selectedCard[5]]);
        card6 = getImage(getDocumentBase(), cards[selectedSuit[6]][selectedCard[6]]);
        card7 = getImage(getDocumentBase(), cards[selectedSuit[7]][selectedCard[7]]);
        card8 = getImage(getDocumentBase(), cards[selectedSuit[8]][selectedCard[8]]);
        card9 = getImage(getDocumentBase(), cards[selectedSuit[9]][selectedCard[9]]);
        card10 = getImage(getDocumentBase(), cards[selectedSuit[10]][selectedCard[10]]);
    }

    public void paint(Graphics g)
    {
        g.drawImage(card1, 30, 30, this);
        g.drawImage(card2, 30, 150, this);
        g.drawImage(card3, 120, 30, this);
        g.drawImage(card4, 120, 150, this);
        g.drawImage(card5, 210, 30, this);
        g.drawImage(card6, 210, 150, this);
        g.drawImage(card7, 300, 30, this);
        g.drawImage(card8, 300, 150, this);
        g.drawImage(card9, 390, 30, this);
        g.drawImage(card10, 390, 150, this);
    }
}

Answer 1

您正在使用基於1的值訪問數組，但是基於0的數組。

異常可能在這里發生：

card10 = getImage(getDocumentBase(), cards[selectedSuit[10]][selectedCard[10]]);

由於您將數組初始化為：

int selectedCard[] = new int[10];

數組的唯一索引為0-9。