成语验证码

1.效果图

 

 

 2.准备一个成语文本文档

eg:

 

 

3.实现代码

public class MyValidCode {
    public static void getCode(int width, int height, HttpServletRequest req, HttpServletResponse resp) throws Exception {
        // TODO Auto-generated method stu
        File file = new File("C:\\Users\\Mike-Qian\\Desktop\\cydq.txt");//成语存放文本中位置
        Random random = new Random();
        int font[]={15,20,25,23,28}; //字体font
        String[] fontNames={"宋体","华文楷体","黑体","微软雅黑","楷体_GB2312","隶书"};//字体类型
        Color[] colors = new Color[] { Color.BLUE, Color.GRAY, Color.GREEN, Color.RED, Color.BLACK, Color.ORANGE,
                Color.CYAN };//字体颜色
        FileInputStream f = new FileInputStream(file);
        BufferedReader br = new BufferedReader(new InputStreamReader(f,"utf-8"));
        ArrayList<String> list = new ArrayList<String>();
        String line=null;
        while((line=br.readLine())!=null)
        {
            list.add(line);
        }
        BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = bi.getGraphics();
        g.setColor(new Color(255, 255, 255));
        g.fillRect(0, 0, width, height);
        for (int i = 0; i < 30; i++) {
            g.setColor(colors[random.nextInt(colors.length)]);
            final int x = random.nextInt(width);
            final int y = random.nextInt(height);
            final int w = random.nextInt(20);
            final int h = random.nextInt(20);
            final int signA = random.nextBoolean() ? 1 : -1;
            final int signB = random.nextBoolean() ? 1 : -1;
            g.drawLine(x, y, x + w * signA, y + h * signB);
        }
        //key
        String str=list.get(random.nextInt(list.size()));
        HttpSession session = req.getSession();
        session.setAttribute("checkCode", str);
        String val=str+list.get(random.nextInt(list.size())).charAt(2);
        char[] charArray = val.toCharArray();
        java.util.List sList = toSuffle(charArray);
        for(int i=0;i<sList.size();i++)
        {
            g.setFont(new Font(fontNames[random.nextInt(font.length)],Font.BOLD,font[random.nextInt(font.length)]));
            g.setColor(colors[random.nextInt(colors.length)]);
            g.drawString(sList.get(i)+"",  i * (width / 5)+5, height - (height / 3));
        }
        resp.setHeader("expires","-1");
        resp.setHeader("PRagma","no-cache");
        resp.setHeader("cache-control","no-cache");
        ImageIO.write(bi,"jpg", resp.getOutputStream());
    }
    private static List toSuffle(char[] arr) {
        ArrayList list = new ArrayList();
        for(int i=0;i<arr.length;i++)
        {
            list.add(arr[i]);
        }
        Collections.shuffle(list);
        return list;
    }
}