生成图片验证码 (一)

1. 工具类

public class VerificationCode {

    private int width = 100;// 生成验证码图片的宽度
    private int height = 30;// 生成验证码图片的高度
    private String[] fontNames = { "宋体", "楷体", "隶书", "微软雅黑" };
    private Color bgColor = new Color(255, 255, 255);// 定义验证码图片的背景颜色为白色
    private Random random = new Random();
    private String codes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    private String text;// 记录随机字符串

    /**
     * 获取一个随意颜色
     * 
     * @return
     */
    private Color randomColor() {
        int red = random.nextInt(150);
        int green = random.nextInt(150);
        int blue = random.nextInt(150);
        return new Color(red, green, blue);
    }

    /**
     * 获取一个随机字体
     * 
     * @return
     */
    private Font randomFont() {
        String name = fontNames[random.nextInt(fontNames.length)];
        int style = random.nextInt(4);
        int size = random.nextInt(5) + 24;
        return new Font(name, style, size);
    }

    /**
     * 获取一个随机字符
     * 
     * @return
     */
    private char randomChar() {
        return codes.charAt(random.nextInt(codes.length()));
    }

    /**
     * 创建一个空白的BufferedImage对象
     * 
     * @return
     */
    private BufferedImage createImage() {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        g2.setColor(bgColor);// 设置验证码图片的背景颜色
        g2.fillRect(0, 0, width, height);
        return image;
    }

    public BufferedImage getImage() {
        BufferedImage image = createImage();
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            String s = randomChar() + "";
            sb.append(s);
            g2.setColor(randomColor());
            g2.setFont(randomFont());
            float x = i * width * 1.0f / 4;
            g2.drawString(s, x, height - 8);
        }
        this.text = sb.toString();
        drawLine(image);
        return image;
    }

    /**
     * 绘制干扰线
     * 
     * @param image
     */
    private void drawLine(BufferedImage image) {
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        int num = 5;
        for (int i = 0; i < num; i++) {
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int x2 = random.nextInt(width);
            int y2 = random.nextInt(height);
            g2.setColor(randomColor());
            g2.setStroke(new BasicStroke(1.5f));
            g2.drawLine(x1, y1, x2, y2);
        }
    }

    public String getText() {
        return text;
    }

    public static void output(BufferedImage image, OutputStream out) throws IOException {
        ImageIO.write(image, "JPEG", out);
    }
}

2. 存入session，并写入页面

@GetMapping("/verifyCode")
public void verifyCode(HttpServletRequest request, HttpServletResponse resp) throws IOException {
        VerificationCode code = new VerificationCode();
        BufferedImage image = code.getImage();
        String text = code.getText();
        HttpSession session = request.getSession(true);
        session.setAttribute("verify_code", text);
        VerificationCode.output(image,resp.getOutputStream());
}

3. 先放在这，等我研究下

public class LoginFilter extends UsernamePasswordAuthenticationFilter {
    @Autowired
    SessionRegistry sessionRegistry;
    @Override
    public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {
        if (!request.getMethod().equals("POST")) {
            throw new AuthenticationServiceException(
                    "Authentication method not supported: " + request.getMethod());
        }
        String verify_code = (String) request.getSession().getAttribute("verify_code");
        if (request.getContentType().contains(MediaType.APPLICATION_JSON_VALUE) || request.getContentType().contains(MediaType.APPLICATION_JSON_UTF8_VALUE)) {
            Map loginData = new HashMap<>();
            try {
                loginData = new ObjectMapper().readValue(request.getInputStream(), Map.class);
            } catch (IOException e) {
            }finally {
                String code = loginData.get("code");
                checkCode(response, code, verify_code);
            }
            String username = loginData.get(getUsernameParameter());
            String password = loginData.get(getPasswordParameter());
            if (username == null) {
                username = "";
            }
            if (password == null) {
                password = "";
            }
            username = username.trim();
            UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(
                    username, password);
            setDetails(request, authRequest);
            Hr principal = new Hr();
            principal.setUsername(username);
            sessionRegistry.registerNewSession(request.getSession(true).getId(), principal);
            return this.getAuthenticationManager().authenticate(authRequest);
        } else {
            checkCode(response, request.getParameter("code"), verify_code);
            return super.attemptAuthentication(request, response);
        }
    }

    public void checkCode(HttpServletResponse resp, String code, String verify_code) {
        if (code == null || verify_code == null || "".equals(code) || !verify_code.toLowerCase().equals(code.toLowerCase())) {
            //验证码不正确
            throw new AuthenticationServiceException("验证码不正确");
        }
    }
}