Java生成随机图片验证码

今天跟大佬学了java随机生成验证码，开心Ing,,,,,激动ing,,,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>
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();}}————————————————
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原文链接：https://blog.csdn.net/qq_32963841/article/details/103182827