0.注意事项：
图片格式（宽、高）、干扰线及数量在工具类的成员变量配置验证码验证。验证码生成后是存储在session中的，使用相同的属性名（类似key）即可取出，然后进行比对1. 验证码生成工具类
package com.jbp.util;import java.awt.*;import java.awt.image.BufferedImage;import java.util.Random;/*** @ClassName: OptimizeVerificationCodeUtil* @description: 验证码生产工具类优化版* @author: JiangBeiPing* @create: -05-12 10:12* @Version: 1.0**/public class OptimizeVerificationCodeUtil {/*** 验证码图片*/private BufferedImage image;/*** 验证码*/private String verificationCode;/*** 生成的验证码的类型（目前的业务类型只需要数字类型）*/private static char[] codeSequence = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};/*** 存入Session的验证码的属性名称*/public static final String SESSION_VERIFICATION_CODE = "validateCode";/*** 设置验证码图片的宽度*/private static final int WIDTH = 600;/*** 设置验证码图片的高度*/private static final int HEIGHT = 200;/*** 设置验证码字符的个数*/private static final int CODE_COUNT = 4;/*** 设置验证码图片干扰线的数量*/private static final int INTERFERING_LINE_COUNT = 160;private OptimizeVerificationCodeUtil() {// 初始化过程中生产并渲染验证码图片init();}/*** 对外提供的本工具类的实例** @return 工具类的实例*/public static OptimizeVerificationCodeUtil instance() {return new OptimizeVerificationCodeUtil();}/*** 获取验证码图片** @return 验证码图片*/public BufferedImage getImage() {return this.image;}/*** 获取验证码** @return 验证码*/public String getVerificationCode() {return this.verificationCode;}private void init() {// 在内存中创建验证码图片BufferedImage bufferedImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);// 获取图形上下文Graphics2D graphics = bufferedImage.createGraphics();try {// 随机数生成器类Random random = new Random();// 图像背景设置为白色graphics.setColor(Color.white);graphics.fillRect(0, 0, WIDTH, HEIGHT);// 创建字体，字体的大小应该根据图片的高度来定Font font = new Font("Fixedsys", Font.PLAIN, HEIGHT - 2);// 设置字体graphics.setFont(font);// 画边框graphics.setColor(Color.BLACK);graphics.drawRect(0, 0, WIDTH - 1, HEIGHT - 1);// 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到for (int i = 0; i < INTERFERING_LINE_COUNT; i++) {// 每条干扰线都设置为随机颜色graphics.setColor(getRandomColor());int x2 = random.nextInt(WIDTH);int y2 = random.nextInt(HEIGHT);int x1 = random.nextInt(WIDTH);int y1 = random.nextInt(HEIGHT);graphics.drawLine(x2, y2, x2 + x1, y2 + y1);}// randomCode用于保存随机产生的验证码，以便用户登录后进行验证StringBuilder randomCode = new StringBuilder();int x = WIDTH / (CODE_COUNT + 1);int codeY = HEIGHT - 4;// 随机产生 codeCount 数字的验证码for (int i = 0; i < CODE_COUNT; i++) {// 获取随机产生的验证码数字String strRand = String.valueOf(codeSequence[random.nextInt(10)]);// 用随机产生的颜色将验证码绘制到图像中graphics.setColor(getRandomColor());graphics.drawString(strRand, (i + 1) * x, codeY);// 将产生的四个随机数组合在一起randomCode.append(strRand);}// 赋值验证码this.verificationCode = String.valueOf(randomCode);// 赋值图像this.image = bufferedImage;} finally {// 不关闭的话有OOM风险graphics.dispose();}}/*** 生成随机颜色* @return 随机颜色*/private static Color getRandomColor() {Random random = new Random();return new Color(random.nextInt(256), random.nextInt(256), random.nextInt(256));}}
2. Controller层
package com.jbp.controller;import com.jbp.util.OptimizeVerificationCodeUtil;import com.jbp.util.VerificationCodeUtil;import lombok.extern.slf4j.Slf4j;import mons.lang.StringUtils;import org.springframework.web.bind.annotation.PostMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RestController;import javax.imageio.ImageIO;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Map;/*** @ClassName: VerificationCodeController* @description: 验证码Controller* @author: JiangBeiPing* @create: -05-11 11:28* @Version: 1.0**/@RequestMapping("/verification")@RestController@Slf4jpublic class VerificationCodeController {@RequestMapping(value = "/getSecurityCode", produces = {"application/json;charset=UTF-8"},method = RequestMethod.GET)public void getSecurityCode(HttpServletResponse response, HttpServletRequest request){// 通知浏览器不要缓存response.setHeader("Expires","-1");response.setHeader("Cache-Control", "no-cache");response.setHeader("Pragma", "-1");// 将验证码输入到session中，用来验证OptimizeVerificationCodeUtil optimizeVerificationCodeUtil = OptimizeVerificationCodeUtil.instance();String verificationCode = optimizeVerificationCodeUtil.getVerificationCode();request.getSession().setAttribute(OptimizeVerificationCodeUtil.SESSION_VERIFICATION_CODE,verificationCode);try {ImageIO.write(optimizeVerificationCodeUtil.getImage(), "jpg", response.getOutputStream());} catch (IOException e) {e.printStackTrace();}}}
3. 效果测试
ps：无视水印，问就是在划水
