SpringSecurity实现图形验证码功能的实例代码

public class ImageCode {
 private BufferedImage image;// 图片
 private String code;// 验证码
 private LocalDateTime expireTime;// 有效时间
 public ImageCode(BufferedImage image, String code, int expireIn) {
 this.image = image;
 this.code = code;
 // 出入一个秒数，自动转为时间，如过期时间为60s，这里的expireIn就是60，转换为当前时间上加上这个秒数
 this.expireTime = LocalDateTime.now().plusSeconds(expireIn);
 }
 public ImageCode(BufferedImage image, String code, LocalDateTime expireTime) {
 this.image = image;
 this.code = code;
 this.expireTime = expireTime;
 }
 public BufferedImage getImage() {
 return image;
 }
 public void setImage(BufferedImage image) {
 this.image = image;
 }
 public String getCode() {
 return code;
 }
 public void setCode(String code) {
 this.code = code;
 }
 public LocalDateTime getExpireTime() {
 return expireTime;
 }
 public void setExpireTime(LocalDateTime expireTime) {
 this.expireTime = expireTime;
 }
}

public class ValidateCodeController {
 private static final String SESSION_KEY = "SESSION_KEY_IMAGE_CODE";
 private SessionStrategy sessionStrategy = new HttpSessionSessionStrategy()；
 @GetMapping("/code/image")
 public void createCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
 // 根据随机数生成图片
 ImageCode imageCode = createImageCode(request);
 // 将随机数存到session中
 sessionStrategy.setAttribute(new ServletWebRequest(request), SESSION_KEY, imageCode);
 // 将生成的图片写到接口的响应中
 ImageIO.write(imageCode.getImage(), "JPEG", response.getOutputStream());
 }

 private ImageCode createImageCode(HttpServletRequest request) {
 // 图片的宽高（像素）
 int width = 67;
 int height = 23;
 // 生成图片对象
 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
 
 Graphics g = image.getGraphics();
 // 生成随机条纹干扰
 Random random = new Random();
 g.setColor(getRandColor(200, 250));
 g.fillRect(0, 0, width, height);
 g.setFont(new Font("Times New Roman", Font.ITALIC, 20));
 g.setColor(getRandColor(160, 200));
 for (int i = 0; i < 155; i++) {
 int x = random.nextInt(width);
 int y = random.nextInt(height);
 int xl = random.nextInt(12);
 int yl = random.nextInt(12);
 g.drawLine(x, y, xl, yl);
 }
 
 // 生成四位随机数
 String sRand = "";
 for (int i = 0; i < 4; i++) {
 String rand = String.valueOf(random.nextInt(10));
 sRand += rand;
 g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
 g.drawString(rand, 13 * i + 6, 16);
 }
 g.dispose();
 // 60秒有效
 return new ImageCode(image, sRand, 60);
 }

 /**
 * 生成随机背景条纹
 * @param fc
 * @param bc
 * @return
 */
 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);
 }
}

ImageCode imageCode = createImageCode(request);

sessionStrategy.setAttribute(new ServletWebRequest(request), SESSION_KEY, imageCode);

ImageIO.write(imageCode.getImage(), “JPEG”, response.getOutputStream());

<tr>
 <td>图形验证码：</td>
 <td>
 <input type="text" name="imageCode">
 <img src="/code/image">
 </td>
</tr>

@Override
protected void configure(HttpSecurity http) throws Exception {
 http.formLogin()
 .loginPage("/authencation/require")
 .loginProcessingUrl("/authentication/form")
 .successHandler(imoocAuthenticationSuccessHandler)
 .failureHandler(imoocAuthenticationFailureHandler)
 .and()
 .authorizeRequests()
 .antMatchers("/authencation/require", 
 securityPropertis.getBrowserPropertis().getLoginPage(),
 "/code/image").permitAll() // 加入"/code/image"地址
 .anyRequest()
 .authenticated()
 .and()
 .csrf().disable();
}

-> 写一个filter进行拦截
public class ValidateCodeFilter extends OncePerRequestFilter{
 private AuthenticationFailureHandler authenticationFailureHandler;
 private SessionStrategy sessionStrategy = new HttpSessionSessionStrategy()；
 @Override
 protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
 throws ServletException, IOException {
 //如果访问的是/authentication/form并且为post请求
 if(StringUtils.equals("/authentication/form", request.getRequestURI())
 && StringUtils.equals(request.getMethod(), "post")) {
 try {
 // 验证图片验证码是否填写正确
 validate(new ServletWebRequest(request));
 } catch (ValidateCodeException e) {
 // 抛出异常，并返回，不再访问资源
 authenticationFailureHandler.onAuthenticationFailure(request, response, e);
 return;
 }
 }
 // 通过，执行后面的filter
 filterChain.doFilter(request, response);
 }
 // 校验验证码的逻辑
 private void validate(ServletWebRequest request) throws ServletRequestBindingException {
 ImageCode codeInSession = (ImageCode) sessionStrategy.getAttribute(request, ValidateCodeController.SESSION_KEY);
 String codeInRequest = ServletRequestUtils.getStringParameter(request.getRequest(), "imageCode");
 if(StringUtils.isBlank(codeInRequest)) {
 throw new ValidateCodeException("验证码的值不能为空");
 }
 if(codeInSession == null){
 throw new ValidateCodeException("验证码不存在");
 }
 if(codeInSession.isExpried()) {
 sessionStrategy.removeAttribute(request, ValidateCodeController.SESSION_KEY);
 throw new ValidateCodeException("验证码已过期");
 }
 if(!StringUtils.equals(codeInSession.getCode(), codeInRequest)) {
 throw new ValidateCodeException("验证码不匹配");
 }
 sessionStrategy.removeAttribute(request, ValidateCodeController.SESSION_KEY);
 }
 public AuthenticationFailureHandler getAuthenticationFailureHandler() {
 return authenticationFailureHandler;
 }
 public void setAuthenticationFailureHandler(AuthenticationFailureHandler authenticationFailureHandler) {
 this.authenticationFailureHandler = authenticationFailureHandler;
 }
 public SessionStrategy getSessionStrategy() {
 return sessionStrategy;
 }
 public void setSessionStrategy(SessionStrategy sessionStrategy) {
 this.sessionStrategy = sessionStrategy;
 }
}

@Override
protected void configure(HttpSecurity http) throws Exception {
 // 声明filter
 ValidateCodeFilter validateCodeFilter = new ValidateCodeFilter();
 // 配置验证失败执行的handler
 validateCodeFilter.setAuthenticationFailureHandler(imoocAuthenticationFailureHandler);
 // 添加filter到认证流程
 http.addFilterBefore(validateCodeFilter, UsernamePasswordAuthenticationFilter.class)
 .formLogin()
 .loginPage("/authencation/require")
 .loginProcessingUrl("/authentication/form")
 .successHandler(imoocAuthenticationSuccessHandler)
 .failureHandler(imoocAuthenticationFailureHandler)
 .and()
 .authorizeRequests()
 .antMatchers("/authencation/require", 
 securityPropertis.getBrowserPropertis().getLoginPage(),
 "/code/image").permitAll()
 .anyRequest()
 .authenticated()
 .and()
 .csrf().disable();
}