生成base64图片流验证码，并存入redis进行登录认证

1.controller中认证写法

2.工具类写法
/**

• ValidateCodeGen

• 功能:图片验证码工具类
  */
  @Component
  public class ValidateCodeGen {

  private String randString = “23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxyz”;//随机产生数字与字母组合的字符串
  private int width = 100;// 图片宽
  private int height = 45;// 图片高
  private int lineSize = 30;// 干扰线数量
  private int stringNum = 4;// 随机产生字符数量

  private Random random = new Random();

  @Autowired
  private RedisDriver redis;

  /*

  • 获得字体
    */
    private Font getFont() {
    return new Font(“Fixedsys”, Font.CENTER_BASELINE, 35);
    }

  /*

  • 获得颜色
    */
    private Color getRandColor(int fc, int bc) {
    if (fc > 255)
    fc = 255;
    if (bc > 255)
    bc = 255;
    int r = fc + random.nextInt(bc - fc - 16);
    int g = fc + random.nextInt(bc - fc - 14);
    int b = fc + random.nextInt(bc - fc - 18);
    return new Color(r, g, b);
    }

  /**

  • 生成随机图片
  • @return
    */
    public String getRandcode(String str) {
    // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
    Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
    g.fillRect(0, 0, width, height);
    g.setFont(new Font(“Times New Roman”, Font.ROMAN_BASELINE, 18));
    g.setColor(getRandColor(110, 133));
    // 绘制干扰线
    for (int i = 0; i <= lineSize; i++) {
    drowLine(g);
    }
    // 绘制随机字符
    String randomString = “”;
    for (int i = 1; i <= stringNum; i++) {
    randomString = drowString(g, randomString, i);
    }
    g.dispose();
    try {
    // 将内存中的图片通过流动形式输出到客户端
    //ImageIO.write(image, “JPEG”, response.getOutputStream());
    } catch (Exception e) {
    e.printStackTrace();
    }
    return randomString;

  }

  //public String getRandcode() {
  public Map getRandcode(HttpServletRequest request,HttpServletResponse response) {
  //String VALIDATE_CODE_KEY = String.valueOf(IdWorker.getInstance().nextId());//生成验证码的key
  HashMap map = new HashMap();
  long startime = System.currentTimeMillis();
  byte[] bf = null;
  ByteArrayOutputStream out = null;
  String uuid = UUID.randomUUID().toString();
  //HttpSession session = request.getSession();
  // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
  BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
  Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
  g.fillRect(0, 0, width, height);
  g.setFont(new Font(“Times New Roman”, Font.ROMAN_BASELINE, 18));
  g.setColor(getRandColor(110, 133));
  // 绘制干扰线
  for (int i = 0; i <= lineSize; i++) {
  drowLine(g);
  }
  // 绘制随机字符
  String randomString = “”;
  for (int i = 1; i <= stringNum; i++) {
  randomString = drowString(g, randomString, i);
  }
  //将验证码对应的key放入session并设置过期时间为3分钟
  //SecurityUtils.getSubject().getSession().setAttribute(uuid,randomString);
  //SecurityUtils.getSubject().getSession().setTimeout(3 * 60 * 1000);
  redis.setStringEx(uuid, 180, randomString);
  g.dispose();

   try {
       // 将内存中的图片通过流动形式输出到客户端
       out = new ByteArrayOutputStream();
       ImageIO.write(image, "JPEG", out);
       bf = out.toByteArray();
   } catch (Exception e) {
       e.printStackTrace();
   }finally {
       if(out != null){
           try {
               out.close();
           } catch (IOException e) {
           }
       }
   }
   long end = System.currentTimeMillis();
   System.err.println((end - startime)/1000);
   map.put("validateCodeKey", uuid);
   map.put("validateCodeBase64", Base64Utils.encodeToString(bf));
   //return Base64Utils.encodeToString(bf);
   return map;
  

  }
  /*

  • 绘制字符串
    */
    private String drowString(Graphics g, String randomString, int i) {
    g.setFont(getFont());
    g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
    .nextInt(121)));
    String rand = String.valueOf(getRandomString(random.nextInt(randString
    .length())));
    randomString += rand;
    g.translate(random.nextInt(3), random.nextInt(3));
    g.drawString(rand, 18 * i - 3, 32);
    return randomString;
    }

  /*

  • 绘制干扰线
    */
    private void drowLine(Graphics g) {
    int x = random.nextInt(width);
    int y = random.nextInt(height);
    int xl = random.nextInt(13);
    int yl = random.nextInt(15);
    g.drawLine(x, y, x + xl, y + yl);
    }

  /*

  • 获取随机的字符
    */
    public String getRandomString(int num) {
    return String.valueOf(randString.charAt(num));
    }

  public boolean check(String uuid, String code) {
  String oldCode = redis.getString(uuid);//(String)SecurityUtils.getSubject().getSession().getAttribute(uuid);//获取Redis中的验证码
  //不管校验成功失败，都清空验证码值
  redis.delKey(uuid);
  //validateCodeKey失效或者跟输入的不匹配，返回提示信息
  if(null == oldCode || StringUtils.isEmpty(oldCode) || !code.equalsIgnoreCase(oldCode)){
  return false;
  }

   return true;
  

  }

}

3.使用img标签和生成的base64流访问

4.Java后台服务自测：启用服务，调用生成验证码接口，然后网页页面输入data:image/gif;base64,（此处填图片转成base64编码后的编码） 网页中直接打开即可