Detailed explanation of the code example of java graphic verification code generation tool web page verification code

This article mainly introduces java graphics in detailVerification codeGeneration tool class , the web page verifies the verification code, which has certain reference value. Interested friends can refer to

recently made verification codes and online cases, and found many problems, which were specially modified and improved. .

Verification codeGenerator:

import javax.imageio.ImageIO;  
import java.awt.*;  
import java.awt.image.BufferedImage;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.OutputStream;  
import java.util.Date;  
import java.util.Random;  
  
/**  
 * 验证码生成器  
 *  
 * @author  
 */  
public class ValidateCode {  
  // 图片的宽度。  
  private int width = 160;  
  // 图片的高度。  
  private int height = 40;  
  // 验证码字符个数  
  private int codeCount = 5;  
  // 验证码干扰线数  
  private int lineCount = 150;  
  // 验证码  
  private String code = null;  
  // 验证码图片Buffer  
  private BufferedImage buffImg = null;  
  
  // 验证码范围,去掉0(数字)和O(拼音)容易混淆的(小写的1和L也可以去掉,大写不用了)  
  private char[] codeSequence = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',  
      'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',  
      'X', 'Y', 'Z', '1', '2', '3', '4', '5', '6', '7', '8', '9'};  
  
  /**  
   * 默认构造函数,设置默认参数  
   */  
  public ValidateCode() {  
    this.createCode();  
  }  
  
  /**  
   * @param width 图片宽  
   * @param height 图片高  
   */  
  public ValidateCode(int width, int height) {  
    this.width = width;  
    this.height = height;  
    this.createCode();  
  }  
  
  /**  
   * @param width   图片宽  
   * @param height  图片高  
   * @param codeCount 字符个数  
   * @param lineCount 干扰线条数  
   */  
  public ValidateCode(int width, int height, int codeCount, int lineCount) {  
    this.width = width;  
    this.height = height;  
    this.codeCount = codeCount;  
    this.lineCount = lineCount;  
    this.createCode();  
  }  
  
  public void createCode() {  
    int x = 0, fontHeight = 0, codeY = 0;  
    int red = 0, green = 0, blue = 0;  
  
    x = width / (codeCount + 2);//每个字符的宽度(左右各空出一个字符)  
    fontHeight = height - 2;//字体的高度  
    codeY = height - 4;  
  
    // 图像buffer  
    buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);  
    Graphics2D g = buffImg.createGraphics();  
    // 生成随机数  
    Random random = new Random();  
    // 将图像填充为白色  
    g.setColor(Color.WHITE);  
    g.fillRect(0, 0, width, height);  
    // 创建字体,可以修改为其它的  
    Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);  
//    Font font = new Font("Times New Roman", Font.ROMAN_BASELINE, fontHeight);  
    g.setFont(font);  
  
    for (int i = 0; i < lineCount; i++) {  
      // 设置随机开始和结束坐标  
      int xs = random.nextInt(width);//x坐标开始  
      int ys = random.nextInt(height);//y坐标开始  
      int xe = xs + random.nextInt(width / 8);//x坐标结束  
      int ye = ys + random.nextInt(height / 8);//y坐标结束  
  
      // 产生随机的颜色值，让输出的每个干扰线的颜色值都将不同。  
      red = random.nextInt(255);  
      green = random.nextInt(255);  
      blue = random.nextInt(255);  
      g.setColor(new Color(red, green, blue));  
      g.drawLine(xs, ys, xe, ye);  
    }  
  
    // randomCode记录随机产生的验证码  
    StringBuffer randomCode = new StringBuffer();  
    // 随机产生codeCount个字符的验证码。  
    for (int i = 0; i < codeCount; i++) {  
      String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);  
      // 产生随机的颜色值，让输出的每个字符的颜色值都将不同。  
      red = random.nextInt(255);  
      green = random.nextInt(255);  
      blue = random.nextInt(255);  
      g.setColor(new Color(red, green, blue));  
      g.drawString(strRand, (i + 1) * x, codeY);  
      // 将产生的四个随机数组合在一起。  
      randomCode.append(strRand);  
    }  
    // 将四位数字的验证码保存到Session中。  
    code = randomCode.toString();  
  }  
  
  public void write(String path) throws IOException {  
    OutputStream sos = new FileOutputStream(path);  
    this.write(sos);  
  }  
  
  public void write(OutputStream sos) throws IOException {  
    ImageIO.write(buffImg, "png", sos);  
    sos.close();  
  }  
  
  public BufferedImage getBuffImg() {  
    return buffImg;  
  }  
  
  public String getCode() {  
    return code;  
  }  
  
  /**  
   * 测试函数,默认生成到d盘  
   * @param args  
   */  
  public static void main(String[] args) {  
    ValidateCode vCode = new ValidateCode(160,40,5,150);  
    try {  
      String path="D:/"+new Date().getTime()+".png";  
      System.out.println(vCode.getCode()+" >"+path);  
      vCode.write(path);  
    } catch (IOException e) {  
      e.printStackTrace();  
    }  
  }  
}

The following is the page JS call verification code

// 刷新图片  
    function changeImg() {  
      var imgSrc = $("#imgObj");  
      var url = imgSrc.attr("src");  
      imgSrc.attr("src", changeUrl(url));  
    }  
    //为了使每次生成图片不一致，即不让浏览器读缓存，所以需要加上时间戳  
    function changeUrl(url) {  
      var timestamp = (new Date()).valueOf();  
      var index = url.indexOf("?"); 
      console.log(index);  
      if (index > 0) {  
        url = url.substring(0, url.indexOf("?"));  
      } 
      console.log(url); 
      if ((url.indexOf("&") > 0)) {  
        url = url + "×tamp=" + timestamp;  
        console.log(url); 
      } else {  
        url = url + "?timestamp=" + timestamp; 
        console.log(url); 
        }  
      return url;  
    }

The following is the controller layer output verification code

/** 
 * 响应验证码页面 
 * @return 
 */  
@RequestMapping(value="/validateCode")  
public String validateCode(HttpServletRequest request,HttpServletResponse response) throws Exception{  
  // 设置响应的类型格式为图片格式  
  response.setContentType("image/jpeg");  
  //禁止图像缓存。  
  response.setHeader("Pragma", "no-cache");  
  response.setHeader("Cache-Control", "no-cache");  
  response.setDateHeader("Expires", 0);  
  
  HttpSession session = request.getSession();  
  
  ValidateCode vCode = new ValidateCode(120,40,5,100);  
  session.setAttribute("code", vCode.getCode());  
  vCode.write(response.getOutputStream());  
  return null;  
}

The following is the controller layer to verify whether the verification code input is correct

String code = request.getParameter("code");  
HttpSession session = request.getSession();  
String sessionCode = (String) session.getAttribute("code");  
if (!StringUtils.equalsIgnoreCase(code, sessionCode)) { //忽略验证码大小写  
  throw new RuntimeException("验证码对应不上code=" + code + " sessionCode=" + sessionCode);  
}

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