这篇文章主要介绍了Spring Security实现验证码登录功能,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

在spring security实现登录注销功能的基础上进行开发。

1、添加生成验证码的控制器。

（1）、生成验证码

/**
   * 引入 Security 配置属性类
   */
  @Autowired
  private SecurityProperties securityProperties;


  @Override
  public ImageCode createCode(HttpServletRequest request ) {
    //如果请求中有 width 参数，则用请求中的，否则用 配置属性中的
    int width = ServletRequestUtils.getIntParameter(request,"width",securityProperties.getWidth());
    //高度（宽度）
    int height = ServletRequestUtils.getIntParameter(request,"height",securityProperties.getHeight());
    //图片验证码字符个数
    int length = securityProperties.getLength();
    //过期时间
    int expireIn = securityProperties.getExpireIn();

    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

    Graphics g = image.getGraphics();

    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, x + xl, y + yl);
    }

    String sRand = "";
    for (int i = 0; i < length; 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();

    return new ImageCode(image, sRand, expireIn);
  }

  /**
   * 生成随机背景条纹
   */
  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);
  }

（2）、验证码控制器

public static final String SESSION_KEY = "SESSION_KEY_IMAGE_CODE";

  @Autowired
  private ValidateCodeGenerator imageCodeGenerator;

  /**
   * Session 对象
   */
  private SessionStrategy sessionStrategy = new HttpSessionSessionStrategy();

  @GetMapping("/code/image")
  public void createCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
    ImageCode imageCode = imageCodeGenerator.createCode(request);
    //将随机数 放到Session中
    sessionStrategy.setAttribute(new ServletWebRequest(request),SESSION_KEY,imageCode);
    request.getSession().setAttribute(SESSION_KEY,imageCode);
    //写给response 响应
    response.setHeader("Cache-Control", "no-store, no-cache");
    response.setContentType("image/jpeg");
    ImageIO.write(imageCode.getImage(),"JPEG",response.getOutputStream());
  }