AbstractSecurityWebApplicationInitializer

注册 Filter:

public class SecurityWebApplicationInitializer extends AbstractSecurityWebApplicationInitializer {
FilterRegistration.Dynamic verificationCodeFilter = servletContext.addFilter(“verificationCodeFilter”, new VerificationCodeFilter());
verificationCodeFilter.addMappingForUrlPatterns(null, false, “/j_captcha.jpg”);
verificationCodeFilter.addMappingForUrlPatterns(null, false, “/index”);

}

jsp:

  <c:url var="loginUrl" value="/index" />  <form action="${loginUrl}" method="post" class="form-horizontal">   <c:if test='${param.verifi != null}'>    <div class="alert alert-success">     <p>验证码错误!</p>    </div>   </c:if>   <label >验证码:</label>     <input name="j_captcha" style="width: 60px" class="form-control" type="text" />          <img id="captchaImg" src="<c:url value='/j_captcha.jpg'/>" />                          </div>   </br>    <input type="submit"  value="登陆"/> <script type="text/javascript">    $("#captchaImg").click(function(){      $('#captchaImg').hide().attr(        'src',        '<c:url value="/j_captcha.jpg"/>'        + '?'+ Math.floor(Math.random() * 100)          ).fadeIn();    });    </script>      </form>

VerificationCode :

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
*

* VerificationCode:
*

* dpica
*
*/
public class VerificationCode {

// 宽private static int WIDTH = 80;// 高private static int HEIGHT = 30;// 验证码数量private static int NUM = 4;// 干扰线数量private static int LINE = 4;private static char[] SHOWTEXT = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',        'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U',        'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7',        '8', '9' };/** * 生成随机的验证码 *  * @return * @throws Exception */public void generator(HttpServletRequest request,        HttpServletResponse response) throws Exception {    Random r = new Random();    // 图片的内存映像    BufferedImage image = new BufferedImage(WIDTH, HEIGHT,            BufferedImage.TYPE_INT_RGB);    // 获得画笔对象    Graphics g = image.getGraphics();    g.setColor(randomColor(200,250));    g.fillRect(0, 0, WIDTH, HEIGHT);    g.setColor(new Color(0,0,0));    // 用于存储随机生成的验证码    StringBuffer number = new StringBuffer();    // 绘制验证码    for (int i = 0; i < NUM; i++) {        g.setColor(randomColor(20,200));        int h = (int) ((HEIGHT * 50 / 100) * r.nextDouble() + (HEIGHT * 50 / 100));        g.setFont(new Font(null, Font.BOLD | Font.ITALIC, h));        String ch = String.valueOf(SHOWTEXT[r.nextInt(SHOWTEXT.length)]);        number.append(ch);        g.drawString(ch, i * WIDTH / NUM * 90 / 100, h);    }    // 绘制干扰线    for (int i = 0; i <= LINE; i++) {        g.setColor(randomColor(100,200));        g.drawLine(r.nextInt(WIDTH), r.nextInt(HEIGHT), r.nextInt(WIDTH),                r.nextInt(HEIGHT));    }    request.getSession().setAttribute("imageCode", number.toString());    //System.out.println("----VerificationCode----" + number.toString());    g.dispose();    //有用    response.reset();    ImageIO.write(image, "jpeg", response.getOutputStream());}private Color randomColor(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);}

}

VerificationCodeFilter :

public class VerificationCodeFilter implements Filter {

@Overridepublic void destroy() {}@Overridepublic void doFilter(ServletRequest arg0, ServletResponse arg1,        FilterChain chain) throws IOException, ServletException {    HttpServletRequest request = (HttpServletRequest) arg0;    HttpServletResponse response = (HttpServletResponse) arg1;    String code = request.getParameter("j_captcha");    String sessionCode = (String) request.getSession().getAttribute(            "imageCode");    String servletPath = request.getServletPath();    String filterProcessesUrl = "/index";    if (StringUtils.startsWith(servletPath, filterProcessesUrl)) {        if (code.equalsIgnoreCase(sessionCode)) {            chain.doFilter(request, response);        } else {            response.sendRedirect("./login?verifi=true");            return;        }    } else {        try {            //response.sendRedirect("./login?verifi=true");            new VerificationCode().generator(request, response);        } catch (Exception e) {            e.printStackTrace();        }    }}@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}