java生成图形验证码

1.开发所需jar包

commons-codec-1.10.jar
commons-lang-2.5.jar
log4j-1.2.17.jar

2.图形验证码工具类代码

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.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletOutputStream;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.commons.codec.digest.DigestUtils;import org.apache.commons.lang3.StringUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;public class CaptchaUtils {    private static final Logger LOG = LoggerFactory.getLogger(CaptchaUtils.class);    private static String captchaName = "captcha";    private static final CaptchaUtils INSTANCE = new CaptchaUtils();    // 默认的验证码大小    private static final int WIDTH = 100, HEIGHT = 46;    // 验证码随机字符数组    private static final String[] strArr = { "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H",            "J", "K", "M", "N", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y" };    // 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)    };    public static CaptchaUtils getInstance() {        return INSTANCE;    }    /**     * 生成验证码     *      * @throws IOException     */    public void render(HttpServletResponse response) throws IOException,Exception {        BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);        String vCode = drawGraphic(image);        vCode = vCode.toUpperCase(); // 转成大写重要        System.out.println(vCode);        vCode = DigestUtils.md5Hex(vCode);        Cookie cookie = new Cookie(captchaName, vCode);        cookie.setMaxAge(-1);        cookie.setPath("/");        try {            // try catch 用来兼容不支持 httpOnly 的 tomcat、jetty            cookie.setHttpOnly(true);        } catch (Exception e) {            LOG.error("", e);        }        response.addCookie(cookie);        response.setHeader("Pragma", "no-cache");        response.setHeader("Cache-Control", "no-cache");        response.setDateHeader("Expires", 0);        response.setContentType("image/jpeg");        ServletOutputStream sos = null;        try {            sos = response.getOutputStream();            ImageIO.write(image, "jpeg", sos);        } catch (IOException e) {            throw e;        } catch (Exception e) {            throw e;        } finally {            if (sos != null) {                try {                    sos.close();                } catch (IOException e) {                    LOG.error("", e);                }            }        }    }    private String drawGraphic(BufferedImage image) {        // 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        g.setColor(getRandColor(200, 250));        g.fillRect(0, 0, WIDTH, HEIGHT);        // 生成随机类        Random random = new Random();        // 设定字体        g.setFont(RANDOM_FONT[random.nextInt(RANDOM_FONT.length)]);        // 画蛋蛋，有蛋的生活才精彩        Color color;        for (int i = 0; i < 10; i++) {            color = getRandColor(120, 200);            g.setColor(color);            g.drawOval(random.nextInt(WIDTH), random.nextInt(HEIGHT), 5 + random.nextInt(10), 5 + random.nextInt(10));            color = null;        }        // 取随机产生的认证码(4位数字)        String sRand = "";        for (int i = 0; i < 4; i++) {            String rand = String.valueOf(strArr[random.nextInt(strArr.length)]);            sRand += rand;            // 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);            // 将认证码显示到图象中            g.drawString(rand, x + 8, y + 10);            // 旋转之后，必须旋转回来            g.rotate(-Math.toRadians(degree), x, y);            color = null;        }        // 图片中间线        g.setColor(getRandColor(0, 60));        // 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();        return sRand;    }    /*     * 给定范围获得随机颜色     */    private Color getRandColor(int fc, int bc) {        Random random = new Random();        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);    }    /**     * 仅能验证一次，验证后立即销毁 cookie     * @param controller 控制器     * @param userInputCaptcha 用户输入的验证码     * @return 验证通过返回 true, 否则返回 false     */    public boolean validate(HttpServletRequest request, HttpServletResponse response, String userInputCaptcha) {        if (StringUtils.isEmpty(userInputCaptcha)) {            return false;        }        request.getCookies();        userInputCaptcha = userInputCaptcha.toUpperCase();  // 转成大写重要        userInputCaptcha = DigestUtils.md5Hex(userInputCaptcha);        boolean result = userInputCaptcha.equals(getCookie(request, captchaName));        if (result == true) {            removeCookie(response, captchaName);        }        return result;    }    private String getCookie(HttpServletRequest request, String name) {        Cookie[] cookies = request.getCookies();        String value = null;        for (Cookie cookie : cookies) {            if (cookie.getName().equals(name)) {                value = cookie.getValue();                break;            }        }        return value;    }    private void removeCookie(HttpServletResponse response, String name) {        Cookie cookie = new Cookie(captchaName, StringUtils.EMPTY);        cookie.setHttpOnly(true);        cookie.setMaxAge(0);            // 0：delete        cookie.setPath("/");        response.addCookie(cookie);    }}

3.调用图形验证码

    @RequestMapping(value="/captcha")    public void captcha(HttpServletRequest request, HttpServletResponse response) {        try {            CaptchaUtils.getInstance().render(response);        } catch(IOException e) {            LOGGER.error("", e);        } catch(Exception e) {            LOGGER.error("", e);        }    }

4.效果
大小：100*46