验证码工具类

import java.awt.BasicStroke;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.RenderingHints;import java.awt.geom.QuadCurve2D;import java.awt.image.BufferedImage;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServletResponse;import com.wangzhixuan.commons.utils.IOUtils;/** * 验证码工具类 */class CaptchaUtils {    // 默认的验证码大小    private static final int WIDTH = 108, HEIGHT = 40, CODE_SIZE = 4;    // 验证码随机字符数组    protected static final char[] charArray = "3456789ABCDEFGHJKMNPQRSTUVWXY".toCharArray();    // 验证码字体    private static final Font[] RANDOM_FONT = new Font[] {        new Font("nyala", Font.BOLD, 38),        new Font("Arial", Font.BOLD, 32),        new Font("Bell MT", Font.BOLD, 32),        new Font("Credit valley", Font.BOLD, 34),        new Font("Impact", Font.BOLD, 32),        new Font(Font.MONOSPACED, Font.BOLD, 40)    };    /**     * 生成验证码     */    static void generate(HttpServletResponse response, String vCode) {        BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);        response.setHeader("Pragma","no-cache");        response.setHeader("Cache-Control","no-cache");        response.setDateHeader("Expires", 0);        response.setContentType("image/jpeg");        ServletOutputStream sos = null;        try {            drawGraphic(image, vCode);            sos = response.getOutputStream();            ImageIO.write(image, "JPEG", sos);            sos.flush();        } catch (Exception e) {            throw new RuntimeException(e);        } finally {            try {               if (sos != null) {                    sos.close();                }            } catch (IOException ioe) {                // ignore            };        }    }    // 生成随机类    private static final Random RANDOM = new Random();    /**     * 生成验证码字符串     * @return 验证码字符串     */    static String generateCode() {        int count = CODE_SIZE;        char[] buffer = new char[count];        for (int i = 0; i < count; i++) {            buffer[i] = charArray[RANDOM.nextInt(charArray.length)];        }        return new String(buffer);    }    private static void drawGraphic(BufferedImage image, String code){        // 获取图形上下文        Graphics2D g = image.createGraphics();        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);        // 图形抗锯齿        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);        // 字体抗锯齿        g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);        // 设定背景色，淡色        g.setColor(getRandColor(210, 250));        g.fillRect(0, 0, WIDTH, HEIGHT);        // 画小字符背景        Color color = null;        for(int i = 0; i < 20; i++){            color = getRandColor(120, 200);            g.setColor(color);            String rand = String.valueOf(charArray[RANDOM.nextInt(charArray.length)]);            g.drawString(rand, RANDOM.nextInt(WIDTH), RANDOM.nextInt(HEIGHT));            color = null;        }        // 取随机产生的认证码(4位数字)        char[] buffer = code.toCharArray();        for (int i = 0; i < buffer.length; i++){            char _code = buffer[i];            //旋转度数 最好小于45度            int degree = RANDOM.nextInt(28);            if (i % 2 == 0) {                degree = degree * (-1);            }            //定义坐标            int x = 22 * i, y = 21;            //旋转区域            g.rotate(Math.toRadians(degree), x, y);            //设定字体颜色            color = getRandColor(20, 130);            g.setColor(color);            //设定字体，每次随机            g.setFont(RANDOM_FONT[RANDOM.nextInt(RANDOM_FONT.length)]);            //将认证码显示到图象中            g.drawString("" + _code, x + 8, y + 10);            //旋转之后，必须旋转回来            g.rotate(-Math.toRadians(degree), x, y);        }        //图片中间曲线，使用上面缓存的color        g.setColor(color);        //width是线宽,float型        BasicStroke bs = new BasicStroke(3);        g.setStroke(bs);        //画出曲线        QuadCurve2D.Double curve = new QuadCurve2D.Double(0d, RANDOM.nextInt(HEIGHT - 8) + 4, WIDTH / 2, HEIGHT / 2, WIDTH, RANDOM.nextInt(HEIGHT - 8) + 4);        g.draw(curve);        // 销毁图像        g.dispose();    }    /**     * 给定范围获得随机颜色     */    private static Color getRandColor(int fc, int bc) {        if (fc > 255)            fc = 255;        if (bc > 255)            bc = 255;        int r = fc + RANDOM.nextInt(bc - fc);        int g = fc + RANDOM.nextInt(bc - fc);        int b = fc + RANDOM.nextInt(bc - fc);        return new Color(r, g, b);    }}