五分钟带你玩转SpringSecurity（八）基操勿6，带你实现验证码功能

@Configuration
public class KaptchaImageCodeConfig {
    @Bean
    public DefaultKaptcha getDefaultKaptcha() {
        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        properties.setProperty(Constants.KAPTCHA_BORDER, "yes");
        properties.setProperty(Constants.KAPTCHA_BORDER_COLOR, "192,192,192");
        properties.setProperty(Constants.KAPTCHA_IMAGE_WIDTH, "110");
        properties.setProperty(Constants.KAPTCHA_IMAGE_HEIGHT, "36");
        properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_FONT_COLOR, "blue");
        properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_FONT_SIZE, "28");
        properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_FONT_NAMES, "宋体");
        properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_CHAR_LENGTH, "4");
        // 图片效果
        properties.setProperty(Constants.KAPTCHA_OBSCURIFICATOR_IMPL, "com.google.code.kaptcha.impl.ShadowGimpy");
        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;
    }
}

@EnableWebSecurity
public class SpringSecurityConfig extends WebSecurityConfigurerAdapter {
    /**
     * 验证码过滤器
     */
    @Autowired
    private ImageCodeValidateFilter imageCodeValidateFilter;
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        // 验证码过滤器
        http.addFilterBefore(imageCodeValidateFilter, UsernamePasswordAuthenticationFilter.class)
            // 跳转前台的地址
            .formLogin().loginPage("/loginPage")
            // 登录调用的接口地址
            .loginProcessingUrl("/login").successHandler(customAuthenticationSuccessHandler);
    }
}

@Component("imageCodeValidateFilter")
public class ImageCodeValidateFilter extends OncePerRequestFilter {
    @Autowired
    SecurityProperties securityProperties;
    @Autowired
    CustomAuthenticationFailureHandler customAuthenticationFailureHandler;
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
        throws ServletException, IOException {
        // 1. 如果是post方式 的登录请求，则校验输入的验证码是否正确
        if ("/login".equals(request.getRequestURI()) && request.getMethod().equalsIgnoreCase("post")) {
            try {
                // 校验验证码合法性
                validate(request);
            } catch (AuthenticationException e) {
                // 交给失败处理器进行处理异常 也就是上文失败返回的json
                customAuthenticationFailureHandler.onAuthenticationFailure(request, response, e);
                // 一定要记得结束
                return;
            }
        }
        // 放行请求 往下执行过滤器
        filterChain.doFilter(request, response);
    }
    private void validate(HttpServletRequest request) {
        // 先获取seesion中的验证码
        String sessionCode = (String)request.getSession().getAttribute(CODE_SESSION_KEY);
        // 获取用户输入的验证码
        String inpuCode = request.getParameter("code");
        // 判断是否正确
        if (StringUtils.isBlank(inpuCode)) {
            throw new ValidateCodeException("验证码不能为空");
        }
        if (!inpuCode.equalsIgnoreCase(sessionCode)) {
            throw new ValidateCodeException("验证码输入错误");
        }
    }
}

@Controller
public class CodeController {
    Logger logger = LoggerFactory.getLogger(getClass());
    @Autowired
    private DefaultKaptcha defaultKaptcha;
    @RequestMapping("/code/image")
    public void imageCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
        // 1. 获取验证码字符串
        String code = defaultKaptcha.createText();
        logger.info("生成的图形验证码是：" + code);
        // 2. 字符串把它放到session中
        request.getSession().setAttribute(CODE_SESSION_KEY, code);
        // 3. 获取验证码图片
        BufferedImage image = defaultKaptcha.createImage(code);
        // 4. 将验证码图片把它写出去
        ServletOutputStream out = response.getOutputStream();
        ImageIO.write(image, "jpg", out);
    }
}