1.验证码工具类1.新建包utils2.新建VerifyCodeUtil类packagecn.coralcloud.ims.utils;importjavax.imageio.ImageIO;importjava.awt.*;importjava.awt.geom.AffineTransform;importjava.awt.image.BufferedImage;importjava.io.File;importjava.io.FileOutputStream;importjava.io.IOException;importjava.io.OutputStream;importjava.util.Arrays;importjava.util.Random;/***@authorc-geff*/publicclassVerifyCodeUtil{/***使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符*/privatestaticfinalStringVERIFY_CODES="23456789ABCDEFGHJKLMNPQRSTUVWXYZ";privatestaticRandomrandom=newRandom();/***使用系统默认字符源生成验证码*@paramverifySize验证码长度*@return*/publicstaticStringgenerateVerifyCode(intverifySize){returngenerateVerifyCode(verifySize,VERIFY_CODES);}/***使用指定源生成验证码*@paramverifySize验证码长度*@paramsources验证码字符源*@return*/publicstaticStringgenerateVerifyCode(intverifySize,Stringsources){if(sources==null||sources.length()==0){sources=VERIFY_CODES;}intcodesLen=sources.length();Randomrand=newRandom(System.currentTimeMillis());StringBuilderverifyCode=newStringBuilder(verifySize);for(inti=0;i<verifySize;i++){verifyCode.append(sources.charAt(rand.nextInt(codesLen-1)));}returnverifyCode.toString();}/***生成随机验证码文件,并返回验证码值*@paramw*@paramh*@paramoutputFile*@paramverifySize*@return*@throwsIOException*/publicstaticStringoutputVerifyImage(intw,inth,FileoutputFile,intverifySize)throwsIOException{StringverifyCode=generateVerifyCode(verifySize);outputImage(w,h,outputFile,verifyCode);returnverifyCode;}/***输出随机验证码图片流,并返回验证码值*@paramw*@paramh*@paramos*@paramverifySize*@return*@throwsIOException*/publicstaticStringoutputVerifyImage(intw,inth,OutputStreamos,intverifySize)throwsIOException{StringverifyCode=generateVerifyCode(verifySize);outputImage(w,h,os,verifyCode);returnverifyCode;}/***生成指定验证码图像文件*@paramw*@paramh*@paramoutputFile*@paramcode*@throwsIOException*/publicstaticvoidoutputImage(intw,inth,FileoutputFile,Stringcode)throwsIOException{if(outputFile==null){return;}Filedir=outputFile.getParentFile();if(!dir.exists()){dir.mkdirs();}try{outputFile.createNewFile();FileOutputStreamfos=newFileOutputStream(outputFile);outputImage(w,h,fos,code);fos.close();}catch(IOExceptione){throwe;}}/***输出指定验证码图片流*@paramw*@paramh*@paramos*@paramcode*@throwsIOException*/publicstaticvoidoutputImage(intw,inth,OutputStreamos,Stringcode)throwsIOException{intverifySize=code.length();BufferedImageimage=newBufferedImage(w,h,BufferedImage.TYPE_INT_RGB);Randomrand=newRandom();Graphics2Dg2=image.createGraphics();g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);Color[]colors=newColor[5];Color[]colorSpaces=newColor[]{Color.WHITE,Color.CYAN,Color.GRAY,Color.LIGHT_GRAY,Color.MAGENTA,Color.ORANGE,Color.PINK,Color.YELLOW};float[]fractions=newfloat[colors.length];for(inti=0;i<colors.length;i++){colors[i]=colorSpaces[rand.nextInt(colorSpaces.length)];fractions[i]=rand.nextFloat();}Arrays.sort(fractions);//设置边框色g2.setColor(Color.GRAY);g2.fillRect(0,0,w,h);Colorc=getRandColor(200,250);//设置背景色g2.setColor(c);g2.fillRect(0,2,w,h-4);//绘制干扰线Randomrandom=newRandom();//设置线条的颜色g2.setColor(getRandColor(160,200));intloop=20;for(inti=0;i<loop;i++){intx=random.nextInt(w-1);inty=random.nextInt(h-1);intxl=random.nextInt(6)+1;intyl=random.nextInt(12)+1;g2.drawLine(x,y,x+xl+40,y+yl+20);}//添加噪点//噪声率floatyawpRate=0.05f;intarea=(int)(yawpRate*w*h);for(inti=0;i<area;i++){intx=random.nextInt(w);inty=random.nextInt(h);intrgb=getRandomIntColor();image.setRGB(x,y,rgb);}//使图片扭曲shear(g2,w,h,c);g2.setColor(getRandColor(100,160));intfontSize=h-4;Fontfont=newFont("Algerian",Font.ITALIC,fontSize);g2.setFont(font);char[]chars=code.toCharArray();for(inti=0;i<verifySize;i++){AffineTransformaffine=newAffineTransform();affine.setToRotation(Math.PI/4*rand.nextDouble()*(rand.nextBoolean()?1:-1),(w/verifySize)*i+fontSize/2,h/2);g2.setTransform(affine);g2.drawChars(chars,i,1,((w-10)/verifySize)*i+5,h/2+fontSize/2-10);}g2.dispose();ImageIO.write(image,"jpg",os);}privatestaticfinalIntegerCOLOR_MAX_INT=255;privatestaticColorgetRandColor(intfc,intbc){if(fc>COLOR_MAX_INT){fc=COLOR_MAX_INT;}if(bc>COLOR_MAX_INT){bc=COLOR_MAX_INT;}intr=fc+random.nextInt(bc-fc);intg=fc+random.nextInt(bc-fc);intb=fc+random.nextInt(bc-fc);returnnewColor(r,g,b);}privatestaticintgetRandomIntColor(){int[]rgb=getRandomRgb();intcolor=0;for(intc:rgb){color=color<<8;color=color|c;}returncolor;}privatestaticint[]getRandomRgb(){int[]rgb=newint[3];intloop=3;for(inti=0;i<loop;i++){rgb[i]=random.nextInt(255);}returnrgb;}privatestaticvoidshear(Graphicsg,intw1,inth1,Colorcolor){shearx(g,w1,h1,color);sheary(g,w1,h1,color);}privatestaticvoidshearx(Graphicsg,intw1,inth1,Colorcolor){intperiod=random.nextInt(2);booleanborderGap=true;intframes=1;intphase=random.nextInt(2);for(inti=0;i<h1;i++){doubled=(double)(period>>1)*Math.sin((double)i/(double)period+(6.2831853071795862D*(double)phase)/(double)frames);g.copyArea(0,i,w1,1,(int)d,0);if(borderGap){g.setColor(color);g.drawLine((int)d,i,0,i);g.drawLine((int)d+w1,i,w1,i);}}}privatestaticvoidsheary(Graphicsg,intw1,inth1,Colorcolor){intperiod=random.nextInt(40)+10;booleanborderGap=true;intframes=20;intphase=7;for(inti=0;i<w1;i++){doubled=(double)(period>>1)*Math.sin((double)i/(double)period+(6.2831853071795862D*(double)phase)/(double)frames);g.copyArea(i,0,1,h1,0,(int)d);if(borderGap){g.setColor(color);g.drawLine(i,(int)d,i,0);g.drawLine(i,(int)d+h1,i,h1);}}}}2.UserController新增验证码接口2.1新增captcha方法@GetMapping("/captcha")publicvoidcaptcha(HttpServletResponseresponse,HttpSessionsession){Stringcode=VerifyCodeUtil.generateVerifyCode(4);session.setAttribute(SessionKey.ADMIN_CAPTCHA_KEY,code);try{VerifyCodeUtil.outputImage(150,50,response.getOutputStream(),code);}catch(IOExceptione){e.printStackTrace();}}2.2修改login方法,增加验证下方为最终的登录验证方法:@PostMapping("/login")publicModelAndViewlogin(Stringemail,Stringpassword,Stringcaptcha,HttpSessionsession){StringsessionCaptcha=(String)session.getAttribute(SessionKey.ADMIN_CAPTCHA_KEY);ModelAndViewview=newModelAndView();view.setViewName("user/login");//将email和password写回到页面,使得登录失败时输入的账号密码不会丢失view.addObject("email",email);view.addObject("password",password);if(StringUtils.isEmpty(captcha)||!Objects.equals(captcha,sessionCaptcha)){view.addObject("errmsg","验证码错误!");returnview;}Useruser=userService.login(email,password);if(user!=null){session.setAttribute(SessionKey.ADMIN_USER_KEY,user);view.setViewName("redirect:/index");returnview;}view.addObject("errmsg","用户名或密码错误!");returnview;}注:此处将Session的Key值通过一个常量类SessionKey保存2.3SessionKey类在utils包下新建SessionKey类packagecn.coralcloud.ims.utils;/***@authorc-geff*@nameSessionKey*@description*@date2020-11-0410:12*/publicclassSessionKey{publicstaticfinalStringADMIN_USER_KEY="AdminUserKey";publicstaticfinalStringADMIN_CAPTCHA_KEY="AdminLoginCaptchaCode";}3.修改login.ftl3.1引入jquery下载jqeury文件jquery.min.js在/static/js文件夹下新建jquery文件夹,将jquery.min.js复制到文件夹下修改login.ftl文件,最终login.ftl内容为下:<!doctypehtml><htmllang="en"xmlns:th="http://www.thymeleaf.org"><head><metacharset="UTF-8"><metaname="viewport"content="width=device-width,user-scalable=no,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0"><metahttp-equiv="X-UA-Compatible"content="ie=edge"><linktype="text/css"rel="stylesheet"href="/static/css/main.css"><linktype="text/css"rel="stylesheet"href="/static/css/login.css"><scriptsrc="/static/js/jquery/jquery.min.js"type="application/javascript"></script><title>用户登录</title></head><body><divclass="login-container"><formaction="/user/login"method="post"><div><h3>用户登录</h3></div><divclass="ims-form-item"><labelclass="ims-form-label"for="email">登录邮箱</label><inputclass="ims-form-input"id="email"autocomplete="off"th:value="${email}"placeholder="请输入邮箱"type="text"name="email"></div><divclass="ims-form-item"><labelclass="ims-form-label"for="password">登录密码</label><inputclass="ims-form-input"id="password"autocomplete="new-password"th:value="${password}"placeholder="请输入密码"type="password"name="password"></div><divclass="ims-form-item"><labelclass="ims-form-label"for="captcha">图片验证</label><inputclass="ims-form-input"id="captcha"type="text"placeholder="请输入图片验证码"name="captcha"><imgsrc="/user/captcha"class="captcha"alt="图片验证码"></div><pclass="errormsg"th:if="${errmsg}!=null"th:text="${errmsg}"></p><div><buttontype="submit"class="ims-button">登录</button></div></form></div></body><scripttype="application/javascript">$(document).ready(function(){$('img.captcha').click(function(){$(this).attr("src","/user/captcha?_="+newDate().getTime())})})</script></html>注,login.ftl变更如下:1.head新增引入jquery.min.js2.input新增读取前面保存的email和password3.新增图片验证码输入框及图片4.新建图片点击监听事件,更换图片验证码4.修改样式login.css#captcha{width:100px;border-top-right-radius:0;border-bottom-right-radius:0;}.captcha{width:1px;flex:1;height:42px;cursor:pointer;border-top-right-radius:4px;border-bottom-right-radius:4px;}5.最终效果