springboot登陆页面图片验证码简单的web项目实现

public class RandomValidateCodeUtil {

  public static final String RANDOMCODEKEY= "RANDOMVALIDATECODEKEY";//放到session中的key
  private String randString = "0123456789";//随机产生只有数字的字符串 private String
  //private String randString = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生只有字母的字符串
  //private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生数字与字母组合的字符串
  private int width = 95;// 图片宽
  private int height = 25;// 图片高
  private int lineSize = 40;// 干扰线数量
  private int stringNum = 4;// 随机产生字符数量

  private static final Logger logger = LoggerFactory.getLogger(RandomValidateCodeUtil.class);

  private Random random = new Random();

  /**
   * 获得字体
   */
  private Font getFont() {
    return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
  }

  /**
   * 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
   */
  public void getRandcode(HttpServletRequest request, HttpServletResponse response) {
    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);//图片大小
    g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));//字体大小
    g.setColor(getRandColor(110, 133));//字体颜色
    // 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);
    }
    logger.info(randomString);
    //将生成的随机字符串保存到session中
    session.removeAttribute(RANDOMCODEKEY);
    session.setAttribute(RANDOMCODEKEY, randomString);
    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) {
      logger.error("将内存中的图片通过流动形式输出到客户端失败>>>>  ", e);
    }

  }

  /**
   * 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, 13 * i, 16);
    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));
  }
}

<!--html/bady代码-->

<div >
  <div >
    <div >
      <input type="tel" id="verify_input" placeholder="请输入验证码" maxlength="4">
    </div>
  </div>
  <div >
    <a href="javascript:void(0);" rel="external nofollow" title="点击更换验证码">
      <img id="imgVerify" src="login/getVerify" alt="更换验证码" height="36" width="170" onclick="getVerify(this);">
    </a>
  </div>
  <input type="button" onclick="aVerify()" value="提交">
</div>
</body>

<!--js中的代码-->
<script type="text/javascript" src="./js/jquery.min.js"></script>
<script>

  //获取验证码
  /*function getVerify(obj){
    obj.src = "login/getVerify?"+Math.random();//原生js方式
  }*/
  
  //获取验证码
  function getVerify() {
    // $("#imgCode").on("click", function() {
    $("#imgVerify").attr("src", 'login/getVerify?' + Math.random());//jquery方式
    // });
  }

  function aVerify(){
    var value =$("#verify_input").val();
    // alert(value);
    $.ajax({
      async: false,
      type: 'post',
      url: 'login/checkVerify',
      dataType: "json",
      data: {
        verifyInput: value
      },
      success: function (result) {
        if (result) {
          alert("success!");
        } else {
          alert("failed!");
        }
        // window.location.reload();
        getVerify();
      }
    });
  }
</script>

@RestController
@RequestMapping("/login")
public class Picverifyaction {
  private final static Logger logger = LoggerFactory.getLogger(Picverifyaction.class);

  /**
   * 生成验证码
   */
  @RequestMapping(value = "/getVerify")
  public void getVerify(HttpServletRequest request, HttpServletResponse response) {
    try {
      response.setContentType("image/jpeg");//设置相应类型,告诉浏览器输出的内容为图片
      response.setHeader("Pragma", "No-cache");//设置响应头信息，告诉浏览器不要缓存此内容
      response.setHeader("Cache-Control", "no-cache");
      response.setDateHeader("Expire", 0);
      RandomValidateCodeUtil randomValidateCode = new RandomValidateCodeUtil();
      randomValidateCode.getRandcode(request, response);//输出验证码图片方法
    } catch (Exception e) {
      logger.error("获取验证码失败>>>>  ", e);
    }
  }

  /**
   * 校验验证码
   */
  @RequestMapping(value = "/checkVerify", method = RequestMethod.POST,headers = "Accept=application/json")
  public boolean checkVerify(@RequestParam String verifyInput, HttpSession session) {
    try{
      //从session中获取随机数
      String inputStr = verifyInput;
      String random = (String) session.getAttribute("RANDOMVALIDATECODEKEY");
      if (random == null) {
        return false;
      }
      if (random.equals(inputStr)) {
        return true;
      } else {
        return false;
      }
    }catch (Exception e){
      logger.error("验证码校验失败", e);
      return false;
    }
  }
}