JAVA后端生成图片滑块验证码 springboot+js完整案例

前言

现在大部分网部都是图片滑块验证码，这个得要与后端联动起来才是确保接口安全性
通过我们系统在发送手机短息时都会选进行滑块验证，但是我们要保证发送短息接口的全安，具体路思如下

那么这个滑块的必须是与后端交互才能保证安全性，而不是前端简单的交互。我们一起来学习一下这个案例怎么实吧
1、验证通过效果如图

2、验证失败效果如图

案例开始

1、我们使用java新建一个springboot工程，并准备几张图片，尺寸是390*180,如下图
添加依赖

<dependency><groupId>net.coobird</groupId><artifactId>thumbnailator</artifactId><version>0.4.11</version>
</dependency>

2、新建三个响应的类
2.1 WebReturn类如下

@Data
public class WebReturn {RetCode code;Object data;public WebReturn(RetCode code, Object data) {this.code = code;this.data = data;}
}

2.2 RetCode类如下

public enum  RetCode {IMAGE_REQ_SUCCESS(1,"图片请求成功"),IMAGE_REQ_FAIL(2,"图片请求失败"),VERIFI_REQ_SUCCESS(3,"图片验证成功"),VERIFI_REQ_FAIL(4,"图片验证失败");int code;String message;RetCode(int code, String message) {this.code = code;this.message = message;}public int getCode() {return code;}public void setCode(int code) {this.code = code;}public String getMessage() {return message;}public void setMessage(String message) {this.message = message;}
}

2.3 ImageResult类如下

@Data
public class ImageResult {int xpos;//滑块的坐标x轴int ypos;//滑块的坐标y轴int cutImageWidth;//滑块的宽int cutImageHeight;//滑块的高String  cutImage;//滑块图片String  oriImage;//背景图（初扣掉滑块的图）}

3、新建一个图片滑块生成的工具类

import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import net.coobird.thumbnailator.Thumbnails;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
@Slf4j
public class ImgUtil {//图片的路径private  String classpath = "classpath*:img/slider/*.*";//图片的最大大小  (可以根据实际需要进行高调整，对应的图片尺寸也得是一致)private  static int IMAGE_MAX_WIDTH = 380;private  static int IMAGE_MAX_HEIGHT = 190;//抠图上面的半径private   static int RADIUS = IMAGE_MAX_WIDTH/38;//抠图区域的高度private   static int CUT_HEIGHT = IMAGE_MAX_WIDTH/7;//抠图区域的宽度private   static int CUT_WIDTH = IMAGE_MAX_WIDTH/7;//被扣地方填充的颜色private   static int FLAG = 0xffffff;//抠图部分凸起的方向private  Location location;ImageResult imageResult = new ImageResult();private  String ORI_IMAGE_KEY = "ORI_IMAGE_KEY";private  String CUT_IMAGE_KEY = "CUT_IMAGE_KEY";private  int XPOS;private  int YPOS;@Dataprivate  class ImageMessage{private int xpos;private int ypos;private int cutImageWidth;private int cutImageHeight;}ImageMessage imageMessage = new ImageMessage();/***功能描述 获取抠图区的坐标原点*/public  void createXYPos(BufferedImage oriImage){int height = oriImage.getHeight();int width = oriImage.getWidth();XPOS = new Random().nextInt(width-CUT_WIDTH-RADIUS);YPOS = new Random().nextInt(height-CUT_HEIGHT-RADIUS-RADIUS)+RADIUS;//确保横坐标位于2/4－－3/4int div = (IMAGE_MAX_WIDTH/4);if(XPOS/div ==  0 ){XPOS = XPOS + div*2;}else if(XPOS/div ==  1 ){XPOS = XPOS + div;}else if(XPOS/div ==  3 ){XPOS = XPOS - div;}}/***功能描述 对外提供的接口*/public  ImageResult imageResult() throws IOException{return imageResult(getRandomImage());}public  ImageResult imageResult(BufferedImage oriBufferedImage) throws IOException {//检测图片大小oriBufferedImage = checkImage(oriBufferedImage);//初始化原点坐标createXYPos(oriBufferedImage);//获取被扣图像的标志图int[][] blockData = getBlockData(oriBufferedImage);//printBlockData(blockData);//计算抠图区域的信息createImageMessage();//获取扣了图的原图和被扣部分的图Map<String,BufferedImage> imageMap =  cutByTemplate(oriBufferedImage,blockData);imageResult.setOriImage(ImageBase64(imageMap.get(ORI_IMAGE_KEY)));imageResult.setCutImage(ImageBase64(imageMap.get(CUT_IMAGE_KEY)));imageResult.setXpos(imageMessage.getXpos());imageResult.setYpos(imageMessage.getYpos());imageResult.setCutImageWidth(imageMessage.getCutImageWidth());imageResult.setCutImageHeight(imageMessage.getCutImageHeight());return imageResult;}/***功能描述* @Description 计算抠图的相关参数*/private  void createImageMessage(){int x = 0,y = 0;int w = 0, h = 0;if(location == Location.UP){x = XPOS;y = YPOS - RADIUS;w = CUT_WIDTH;h = CUT_HEIGHT + RADIUS;}else if(location == Location.LEFT){x = XPOS-RADIUS;y = YPOS;w = CUT_WIDTH + RADIUS;h = CUT_HEIGHT;}else if(location == Location.DOWN){x = XPOS;y = YPOS;w = CUT_WIDTH;h = CUT_HEIGHT + RADIUS;}else if(location == Location.RIGHT){x = XPOS;y = YPOS;w = CUT_WIDTH + RADIUS;h = CUT_HEIGHT;}imageMessage.setXpos(x);imageMessage.setYpos(y);imageMessage.setCutImageHeight(h);imageMessage.setCutImageWidth(w);}/***功能描述* @Description  检测图片大小是否符合要求*/private  BufferedImage checkImage(BufferedImage image) throws IOException {if((image.getWidth()  == IMAGE_MAX_WIDTH) || (image.getHeight()  == IMAGE_MAX_HEIGHT)){return image;}else if((image.getWidth()  < IMAGE_MAX_WIDTH) || (image.getHeight()  < IMAGE_MAX_HEIGHT)){log.info("图片太小．不符合要求w*h[380*190]");throw  new IllegalArgumentException("图片太小．不符合要求w*h[380*190]");} else {log.info("压缩图片");return compressImage(image,IMAGE_MAX_WIDTH,IMAGE_MAX_HEIGHT);}}private Color color(int rgb){int b = (0xff & rgb);int g = (0xff & (rgb >> 8));int r = (0xff & (rgb >> 16));return new Color(r, g, b);}/***功能描述 获取抠完图的原图和被扣出来的图*/public  Map<String,BufferedImage> cutByTemplate(BufferedImage oriImage,  int[][] blockData){Map<String,BufferedImage> imgMap = new HashMap<>();BufferedImage cutImage = new BufferedImage(imageMessage.cutImageWidth,imageMessage.cutImageHeight,oriImage.getType());// 获取Graphics2DGraphics2D g2d = cutImage.createGraphics();//透明化整张图cutImage = g2d.getDeviceConfiguration().createCompatibleImage(imageMessage.cutImageWidth,imageMessage.cutImageHeight, Transparency.BITMASK);g2d.dispose();g2d = cutImage.createGraphics();// 背景透明代码结束int xmax = imageMessage.xpos + imageMessage.cutImageWidth;int ymax = imageMessage.ypos + imageMessage.cutImageHeight;for(int x = imageMessage.xpos; x< xmax && x>=0; x++){for(int y = imageMessage.ypos; y < ymax && y>=0; y++){int oriRgb = oriImage.getRGB(x,y);if(blockData[x][y] == FLAG){oriImage.setRGB(x,y,FLAG);//描边   判断是否为边界，如果是边界则填充为白色if(blockData[x-1][y] != FLAG || blockData[x+1][y] != FLAG || blockData[x][y+1] != FLAG || blockData[x][y-1] != FLAG){g2d.setColor(color(0xffffff));}else{g2d.setColor(color(oriRgb));}g2d.setStroke(new BasicStroke(1f));g2d.fillRect(x-imageMessage.xpos, y-imageMessage.ypos, 1, 1);}}}// 释放对象g2d.dispose();imgMap.put(ORI_IMAGE_KEY,oriImage);imgMap.put(CUT_IMAGE_KEY,cutImage);return imgMap;}/***功能描述* @Description 获取抠图数据，被扣的像素点将使用FLAG进行标记* @return:  int[][]*/public  int[][] getBlockData(BufferedImage oriImage){int height = oriImage.getHeight();int width = oriImage.getWidth();int[][] blockData =new int[width][height];Location locations[] = {Location.UP,Location.LEFT,Location.DOWN,Location.RIGHT};//矩形//此处还可以优化，进行区域扫描for(int x = 0; x< width && x>=0; x++){for(int y = 0; y < height && y>=0; y++){blockData[x][y] = 0;if ( (x > XPOS) && (x < (XPOS+CUT_WIDTH))&& (y > YPOS) && (y < (YPOS+CUT_HEIGHT))){blockData[x][y] = FLAG;}}}//圆形突出区域//突出圆形的原点坐标(x,y)int xBulgeCenter=0,yBulgeCenter=0;int xConcaveCenter=0,yConcaveCenter=0;//位于矩形的哪一边，0123--上下左右location = locations[new Random().nextInt(4)];if(location == Location.UP){//上 凸起xBulgeCenter = XPOS +  CUT_WIDTH/2;yBulgeCenter = YPOS;//左　凹陷xConcaveCenter = XPOS ;yConcaveCenter = YPOS + CUT_HEIGHT/2;}else if(location == Location.DOWN){//下　凸起xBulgeCenter = XPOS +  CUT_WIDTH/2;yBulgeCenter = YPOS + CUT_HEIGHT;//右　凹陷xConcaveCenter = XPOS +  CUT_WIDTH;yConcaveCenter = YPOS + CUT_HEIGHT/2;}else if(location == Location.LEFT){//左　凸起xBulgeCenter = XPOS ;yBulgeCenter = YPOS + CUT_HEIGHT/2;//下　凹陷xConcaveCenter = XPOS +  CUT_WIDTH/2;yConcaveCenter = YPOS + CUT_HEIGHT;}else {//Location.RIGHT//右　凸起xBulgeCenter = XPOS +  CUT_WIDTH;yBulgeCenter = YPOS + CUT_HEIGHT/2;//上　凹陷xConcaveCenter = XPOS +  CUT_WIDTH/2;yConcaveCenter = YPOS;}//半径的平方int RADIUS_POW2 = RADIUS * RADIUS;//凸起部分for(int x = xBulgeCenter-RADIUS; x< xBulgeCenter+RADIUS && x>=0; x++){for(int y = yBulgeCenter-RADIUS; y < yBulgeCenter+RADIUS && y>=0; y++){if(Math.pow((x-xBulgeCenter),2) + Math.pow((y-yBulgeCenter),2) < RADIUS_POW2){blockData[x][y] = FLAG;}}}//凹陷部分for(int x = xConcaveCenter-RADIUS; x< xConcaveCenter+RADIUS && x>=0; x++){for(int y = yConcaveCenter-RADIUS; y < yConcaveCenter+RADIUS && y>=0; y++){if(Math.pow((x-xConcaveCenter),2) + Math.pow((y-yConcaveCenter),2) <= RADIUS_POW2){blockData[x][y] = 0;}}}return blockData;}/***功能描述 将图片转为base64存储*/private  String ImageBase64(BufferedImage bufferedImage) throws IOException {ByteArrayOutputStream out = new ByteArrayOutputStream();ImageIO.write(bufferedImage, "png", out);//转成byte数组byte[] bytes = out.toByteArray();Base64.Encoder encoder = Base64.getEncoder();//生成BASE64编码return encoder.encodeToString(bytes);}/*** 随机获取一个图片文件* @return* @throws Exception*/private  BufferedImage getRandomImage() throws IOException {try {//使用resource获取resource文件【注意：即使打成jar包也有效】ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();Resource[] resources = resourcePatternResolver.getResources(classpath);if (resources.length <= 0) {throw new IOException("该文件夹内没有文件！");} else {int index = new Random().nextInt(resources.length);InputStream inputStream = resources[index].getInputStream();BufferedImage marioBufferedImage = ImageIO.read(inputStream);return marioBufferedImage;}} catch (IOException e) {log.info("读取文件失败：{}", e);throw new IOException("读取文件失败！");}}/***功能描述  压缩图片* @author lgj* @Description* @date 3/30/20* @param:* @return:  java.awt.image.BufferedImage**/private  BufferedImage compressImage(BufferedImage image,int width,int height) throws IOException{return  Thumbnails.of(image).forceSize(width,height)//.width(width).height(height).asBufferedImage();}/***功能描述* @Description  抠图部分凸起的区域*/private enum Location {UP,LEFT,DOWN,RIGHT;}
}

4、新建一个controller

@Slf4j
@RestController
@RequestMapping("/slider")
public class SliderController {private  int xPosCache = 0;//生产环境请把这个值存入redis中@RequestMapping("/image")public WebReturn image(){ImageResult imageResult = null;try{imageResult = new ImgUtil().imageResult();//生成图片xPosCache = imageResult.getXpos();//生产环境请把这个值存入redis中imageResult.setXpos(0);//清空x值return new WebReturn(RetCode.IMAGE_REQ_SUCCESS,imageResult);}catch(Exception ex){log.error(ex.getMessage());ex.printStackTrace();return new WebReturn(RetCode.IMAGE_REQ_FAIL,null);}}@RequestMapping("/verification")public WebReturn verification(@RequestParam("moveX") int moveX){log.info("/slider/verification/{}",moveX);int MOVE_CHECK_ERROR = 2;//允许的误差范围，这里设置为2个像素//xPosCache   生产请从redis中读取，使用完并立即请除if(( moveX < ( xPosCache + MOVE_CHECK_ERROR)) && ( moveX >  (xPosCache - MOVE_CHECK_ERROR))){log.info("验证正确");//生产这个可以返回临时授权码return new WebReturn(RetCode.VERIFI_REQ_SUCCESS,true);}return new WebReturn(RetCode.VERIFI_REQ_FAIL,false);}
}

5、最后新建一个页面

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>首页</title><script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script><style >html body {height: 100%;width: 100%;}#captchaContainer{position: absolute;top: 50px;left: 40%;/*  background-color: #f57a7a;*/height: 275px;width: 260px;}.header{position: absolute;top: 0px;left: 0px;background-color: rgb(245, 236, 236);height: 40px;width: 380px;}.headerText{position: absolute;top: 13px;left: 140px;height: 40px;color:#66c523;font:18px/14px Georgia, "Times New Roman", Times, serif;}#captchaImg{position: absolute;left: 0;top: 40px;height: 190px;width: 380px;-webkit-user-select: none;-moz-user-select: none;-ms-user-select: none;user-select: none;border: none}#oriImg{position: absolute;left: 0px;top: 0px;width: 380px;height: 190px;-webkit-user-select: none;-moz-user-select: none;-ms-user-select: none;user-select: none;border: none}#cutImg{position: absolute;border: none;left: 0px;}.sliderContainer {position: absolute;bottom: 0;left: 0px;text-align: center;width: 380px;height: 40px;line-height: 40px;background: #f7f9fa;color: #45494c;border: 1px solid #e4e7eb;}.sliderContainer_success{border: 1px solid hsl(125, 93%, 44%);}.sliderContainer_fail{border: 1px solid #ec3655;}.slider {position: absolute;top: 0;left: 0px;width: 40px;height: 40px;background: #fff;box-shadow: 0 0 3px rgba(0, 0, 0, 0.3);transition: background .2s linear;cursor: pointer;cursor: grab;}.slider_success{border: 1px solid hsl(125, 93%, 44%);}.slider_fail{border: 1px solid #ec3655;}.sliderContainer_active .slider {height: 38px;top: -1px;border: 1px solid #1991FA;}.sliderContainer_active .sliderMask {height: 38px;border-width: 1px;}.sliderContainer_success .slider {height: 38px;top: -1px;margin-left: -1px;border: 1px solid #52CCBA;background-color: #52CCBA !important;}.sliderContainer_success .sliderMask {height: 38px;border: 1px solid #52CCBA;background-color: #D2F4EF;}.sliderContainer_success .sliderIcon {background-position: 0 0 !important;}.sliderContainer_fail .slider {height: 38px;top: -1px;border: 1px solid #f57a7a;background-color: #f57a7a !important;}.sliderContainer_fail .sliderMask {height: 38px;border: 1px solid #f57a7a;background-color: #fce1e1;}.sliderContainer_fail .sliderIcon {top: 14px;background-position: 0 -82px !important;}.sliderContainer_active .sliderText, .sliderContainer_success .sliderText, .sliderContainer_fail .sliderText {display: none;}.sliderMask {position: absolute;left: 0;top: 0;height: 40px;border: 0 solid #1991FA;background: #D1E9FE;}.slider:active {cursor: grabbing;}.slider:hover {background: #1991FA;}.slider:hover .sliderIcon {background-position: 0 -13px;}.sliderIcon {position: absolute;top: 15px;left: 13px;width: 14px;height: 12px;background: url(http://cstaticdun.126.net//2.6.3/images/icon_light.f13cff3.png) 0 -26px;background-size: 34px 471px;}.refreshIcon {position: absolute;right: 0;top: 0;width: 34px;height: 34px;cursor: pointer;background: url(http://cstaticdun.126.net//2.6.3/images/icon_light.f13cff3.png) 0 -437px;background-size: 34px 471px;}</style></head>
<body><div id="captchaContainer"><!-- 标题栏　--><div class="header"><span class="headerText">图片滑动验证</span><span class="refreshIcon"/></div> <!-- 图片显示区域　--><div id="captchaImg"><img id="oriImg" src="dd" alt="原图"/><img id="cutImg" src="sa" alt="抠图"/></div><!--滑块显示区域--><div class="sliderContainer"><div class="sliderMask"><div class="slider"><span class="sliderIcon"></span></div></div><span class="sliderText">向右滑动填充拼图</span></div> </div></body><script>//图片显示使用base64时的前缀,src=base64PrefixPath + imgBase64Valuevar base64PrefixPath="data:image/png;base64,";var IMAGE_WIDTH = 380;//初始化//滑块初始偏移量var sliderInitOffset = 0;//滑块移动的最值var MIN_MOVE = 0;var MAX_MOVE = 0;//鼠标按下标志var mousedownFlag=false;//滑块移动的距离var moveX;//滑块位置检测允许的误差，正负２var MOVE_CHECK_ERROR = 2;//滑块滑动使能var moveEnable = true;var ImageMsg = {//抠图的坐标xpos: 0,ypos: 0,//抠图的大小cutImageWidth: 0,cutImageHeight: 0,//原图的base64oriImageSrc: 0,//抠图的base64cutImageSrc: 0,}//加载页面时进行初始化function init(){console.log("init")moveEnable = true;mousedownFlag=false;$(".slider").css("left",0+"px");initClass();MAX_MOVE = IMAGE_WIDTH - ImageMsg.cutImageWidth;console.log("ImageMsg = " + ImageMsg)$("#cutImg").css("left",0+"px");$("#oriImg").attr("src",ImageMsg.oriImageSrc)$("#cutImg").attr("src",ImageMsg.cutImageSrc)$("#cutImg").css("width",ImageMsg.cutImageWidth)$("#cutImg").css("height",ImageMsg.cutImageHeight)$("#cutImg").css("top",ImageMsg.ypos)}//加载页面时$(function(){httpRequest.requestImage.request();})var httpRequest={//请求获取图片requestImage:{path: "slider/image",request:function(){$.get(httpRequest.requestImage.path,function(data,status){console.log(data)console.log(data.message);if(data.data != null){ImageMsg.oriImageSrc = base64PrefixPath + data.data.oriImage;ImageMsg.cutImageSrc = base64PrefixPath + data.data.cutImage;ImageMsg.xpos = data.data.xpos;ImageMsg.ypos = data.data.ypos;ImageMsg.cutImageWidth = data.data.cutImageWidth;ImageMsg.cutImageHeight = data.data.cutImageHeight;init();}});},},//请求验证requestVerification:{path: "slider/verification",request:function(){$.get(httpRequest.requestVerification.path,{moveX:(moveX)},function(data,status){console.log(data)console.log(data.code);console.log(data.message);if(data.data == true){checkSuccessHandle();}else{checkFailHandle();}});},},}//刷新图片操作$(".refreshIcon").on("click",function(){httpRequest.requestImage.request();})//滑块鼠标按下$(".slider").mousedown(function(event){console.log("鼠标按下mousedown:"+event.clientX + " " + event.clientY);sliderInitOffset = event.clientX;  mousedownFlag = true;//滑块绑定鼠标滑动事件$(".slider").on("mousemove",function(event){if(mousedownFlag  == false){return;}if(moveEnable == false){return}moveX = event.clientX - sliderInitOffset;moveX<MIN_MOVE?moveX=MIN_MOVE:moveX=moveX;moveX>MAX_MOVE?moveX=MAX_MOVE:moveX=moveX;$(this).css("left",moveX+"px");$("#cutImg").css("left",moveX+"px");})})//滑块鼠标弹起操作$(".slider").mouseup(function(event){console.log("mouseup:"+event.clientX + " " + event.clientY);sliderInitOffset = 0;$(this).off("mousemove");mousedownFlag=false;console.log("moveX　＝　" + moveX)checkLocation();})//检测滑块　位置是否正确function checkLocation(){moveEnable = false;//后端请求检测滑块位置httpRequest.requestVerification.request();}function checkSuccessHandle(){$(".sliderContainer").addClass("sliderContainer_success");$(".slider").addClass("slider_success");}function checkFailHandle(){$(".sliderContainer").addClass("sliderContainer_fail");$(".slider").addClass("slider_success");}function initClass(){$(".sliderContainer").removeClass("sliderContainer_success");$(".slider").removeClass("slider_success");$(".sliderContainer").removeClass("sliderContainer_fail");$(".slider").removeClass("slider_fail");}</script></html>

最后

到这里我们的案例代码已经写好了，运程工程访问就可以了。
http://localhost:9005/home.html

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