java 生成网页图片验证码的工具类

た入场券 2024-04-01 19:46 18阅读 0赞

import javax.imageio.ImageIO;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpSession;
    import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.util.Random;
    
      public class RandomValidateCodeUtil {
      
      
          //TODO 图片验证生成器
      
        //  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 String 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,sessionId一直变化放弃该种方式
             // 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) {
                  throw new CustomerException("将内存中的图片通过流动形式输出到客户端失败>>>> ", e);
              }
    
              return randomString;
          }
      
          /**
           * 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));
          }
      }

挺好用的