本文实例为大家分享了java生成随机图片验证码的具体代码，供大家参考，具体内容如下

效果如图

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")@ResponseBodypublic 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(); } }

更多关于验证码的文章请点击查看： 《java验证码》

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。