Java生成随机图片验证码

素颜马尾好姑娘i 2023-06-15 07:27 152阅读 0赞

效果如图

![20191122082405258.jpg][]

前台html代码

<div style="margin-top: 50px;">
            <span>验证码：</span><input type="text" name="verifyCode" id="verifyCode" style="width: 75px;height: 25px;"/>
            <img id="verifyCodeImg" alt="点击更换" src="/qos/dog/getVerifyCodeImg"
                title="点击更换" onclick="change()">
        </div>
    
    
    
    
    注释：此处的src="/qos/dog/getVerifyCodeImg"   SpringBoot页面展示Thymeleaf的语法

前台js代码

function change() {
            var verifyCode = document.getElementById("verifyCodeImg");
            verifyCode.src = "/qos/dog/getVerifyCodeImg?time=" + Math.random(1000);
        }
    
    
    
    /*-*/
    
    /qos/dog/  这里的路径是需要换成自己的哦

验证代码，在controller里面新建一个util文件夹，然后放入VerifyCodeUtil.java

代码如下

package com.paladin.qos.util;
    
    import javax.imageio.ImageIO;
    import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.util.Random;
    
    public class VerifyCodeUtil {
    
        private static final Random random = new Random();
        private static final String[] fontNames = {"宋体", "华文楷体", "黑体", "Georgia", "微软雅黑", "楷体_GB2312"};
    
        public static String drawImage(ByteArrayOutputStream output) {
            String code = "";
            int width = 50;
            int height = 25;
    
            //创建图片缓冲区
            BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);
    
            Graphics2D g = bi.createGraphics();
    
            //设置背景颜色
            g.setBackground(new Color(255, 255, 255));
            g.clearRect(0, 0, width, height);
    
            StringBuilder stringBuilder = new StringBuilder();
            //这里只画入四个字符
            for (int i = 0; i < 4; i++) {
                String s = randomChar() + "";      //随机生成字符，因为只有画字符串的方法，没有画字符的方法，所以需要将字符变成字符串再画
                stringBuilder.append(s);           //添加到StringBuilder里面
                float x = i * 1.0F * width / 4;   //定义字符的x坐标
                g.setFont(randomFont());           //设置字体，随机
                g.setColor(randomColor());         //设置颜色，随机
                g.drawString(s, x, height - 5);
            }
            code = stringBuilder.toString();//获取验证码字符串
    
            //定义干扰线
            //定义干扰线的数量（3-5条）int num = random.nextInt(max)%(max-min+1) + min;
            int num = random.nextInt(5) % 3 + 3;
            Graphics2D graphics = (Graphics2D) bi.getGraphics();
            for (int i = 0; i < num; i++) {
                int x1 = random.nextInt(width);
                int y1 = random.nextInt(height);
                int x2 = random.nextInt(width);
                int y2 = random.nextInt(height);
                graphics.setColor(randomColor());
                graphics.drawLine(x1, y1, x2, y2);
            }
            // 释放图形上下文
            g.dispose();
            try {
                ImageIO.write(bi, "jpg", output);
            } catch (IOException e) {
                e.printStackTrace();
            }
            return code;//为了方便取值，直接返回code，
    
    
    
        }
    
        //随机字体
        private static Font randomFont() {
            int index = random.nextInt(fontNames.length);
            String fontName = fontNames[index];
            int style = random.nextInt(4);         //随机获取4种字体的样式
            int size = random.nextInt(20) % 6 + 15;    //随机获取字体的大小(10-20之间的值)
            return new Font(fontName, style, size);
        }
    
        //随机颜色
        private static Color randomColor() {
            int r = random.nextInt(225);
            int g = random.nextInt(225);
            int b = random.nextInt(225);
            return new Color(r, g, b);
        }
    
    
        //随机字符
        private static char randomChar() {
            //A-Z,a-z,0-9,可剔除一些难辨认的字母与数字
            String str = "0123456789ABCdefghiDEFGHIJopPQRVWXYZabcjklSTUmnqrstKLMNOvuwxyz";
    
            return str.charAt(random.nextInt(str.length()));
        }
    
    }

最后，在controller里面引用

@RequestMapping("/getVerifyCodeImg")
        @ResponseBody
        public void getVerifyCodeImg(HttpServletResponse response, HttpSession session) {
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            String code = VerifyCodeUtil.drawImage(output);
            //将验证码文本直接存放到session中
            session.setAttribute("verifyCode", code);
            try {
                ServletOutputStream out = response.getOutputStream();
                output.writeTo(out);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

[20191122082405258.jpg]: https://img-blog.csdnimg.cn/20191122082405258.jpg