20220415_二维码生成器学习笔记
1概述
一般大家使用这种功能都是为了实现业务，例如常见的扫描二维码跳转链接（页面），扫描二维码出现文字等等。有些二维码中间还带有 Logo 这种图片，将需要嵌入二维码的图片路径准备好就没有问题。
本文基于google的zxing依赖包,进行二维码生成展示的代码示例学习。
效果演示:
浏览器输入如下地址,回车,
image-20220416160315390.png
手机扫描,则自动跳入百度页面，点击显示二维码按钮,则显示内容。
1.1二维码原理
1.1.1线性堆叠式二维码
1.1.2矩阵式二维码(最为常用的类型)
在一个矩形空间通过黑、白像素在矩阵中的不同分布进行编码。
1.1.3邮政码
1.2生成二维码方法
-
借助第三方jar
如:zxing和qrcodejar
zxing:是一个开源的、多格式的一维/二维条码图像处理库，用 Java 实现，可移植到其他语言。
-
Javascript
如jquery.qrcode.js
2代码示例
2.1maven依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<!--设置继承的父模块-->
<parent>
<artifactId>C200myqrcodedemo</artifactId>
<groupId>com.kikop</groupId>
<version>0.0.1-SNAPSHOT</version>
<relativePath>../pom.xml</relativePath>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>myzxingemo</artifactId>
<name>${project.artifactId}</name>
<description>quickstart project</description>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<!--optional:两个项目直接不依赖传递-->
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!--4.fastjson-->
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>${fastjson.version}</version>
</dependency>
<!--5.google二维码生成依赖包-->
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.4.1</version>
</dependency>
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>javase</artifactId>
<version>3.4.1</version>
</dependency>
</dependencies>
</project>
2.2后台编写
2.2.1MyQrCodeUtils
package com.kikop.utils;
import com.google.zxing.*;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import com.kikop.myconst.ConstVarManager;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.Hashtable;
/**
* @author kikop
* @version 1.0
* @project myzxingdemo
* @file MyQrCodeUtils
* @desc 二封装维码生成工具类
* @date 2022/04/16
* @time 20:39
* @by IDE: IntelliJ IDEA
*/
public class MyQrCodeUtils {
private static final String CHARSET = "utf-8";
public static final String FORMAT_NAME = "jpeg";
// 二维码尺寸
private static final int QRCODE_SIZE = 300;
// LOGO图片宽度,原始图片大于会出错
private static final int WIDTH = 60;
// LOGO图片高度
private static final int HEIGHT = 60;
/**
* 生成二维码
*
* @param content 存放在二维码中的内容,二维码中的内容可以是文字，可以是链接等
* @param logoImgPath(C:\Users\kikop\myuploadfile\tiger.jpg)
* @param destPath 生成的二维码存放路径(C:\Users\kikop\myuploadfile\1.jpg)
* @param needCompress 是否需要压缩
* @throws Exception
*/
public static void create(String content, String logoImgPath, String destPath, boolean needCompress) throws Exception {
BufferedImage image = createImage(content, logoImgPath, needCompress);
mkdirs(destPath);
ImageIO.write(image, FORMAT_NAME, new File(destPath));
}
/**
* 获取二维码内容
*
* @param path
* @return
* @throws Exception
*/
public static String decodeContent(String path) throws Exception {
return decode(new File(path));
}
private static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
throws Exception {
BufferedImage image = createImage(content, imgPath, needCompress);
ImageIO.write(image, FORMAT_NAME, output);
}
private static String decode(File file) throws Exception {
BufferedImage image;
image = ImageIO.read(file);
if (image == null) {
return null;
}
BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
Result result;
Hashtable qrcodeParam = new Hashtable();
qrcodeParam.put(DecodeHintType.CHARACTER_SET, CHARSET);
result = new MultiFormatReader().decode(bitmap, qrcodeParam);
String resultStr = result.getText();
return resultStr;
}
private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception {
Hashtable qrcodeParam = new Hashtable();
qrcodeParam.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); // 指定二维码的纠错等级为中级
qrcodeParam.put(EncodeHintType.CHARACTER_SET, CHARSET); //指定字符编为“utf-8”
qrcodeParam.put(EncodeHintType.MARGIN, 1); //设置图片的边距
BitMatrix bitMatrix = new MultiFormatWriter().encode(
content,
BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE,
qrcodeParam);
int width = bitMatrix.getWidth();
int height = bitMatrix.getHeight();
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
}
}
if (imgPath == null || "".equals(imgPath)) {
return image;
}
// 插入Logo图片
insertLogoImage(image, imgPath, needCompress);
return image;
}
private static void insertLogoImage(BufferedImage srcBufferedImage, String imgPath, boolean needCompress) throws Exception {
File file = new File(imgPath);
if (!file.exists()) {
System.err.println("" + imgPath + " 该文件不存在！");
return;
}
Image srcLogoImage = ImageIO.read(new File(imgPath));
int width = srcLogoImage.getWidth(null);
int height = srcLogoImage.getHeight(null);
if (needCompress) { // 压缩LOGO
if (width > WIDTH) {
width = WIDTH;
}
if (height > HEIGHT) {
height = HEIGHT;
}
Image scaledLogoImage = srcLogoImage.getScaledInstance(width, height, Image.SCALE_SMOOTH);
BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = tag.getGraphics();
g.drawImage(scaledLogoImage, 0, 0, null); // 绘制缩小后的图
g.dispose();
srcLogoImage = scaledLogoImage;
}
// 二维码中插入LOGO
Graphics2D graph = srcBufferedImage.createGraphics();
// 必须压缩,计算问题 todo
int x = (QRCODE_SIZE - width) / 2;
int y = (QRCODE_SIZE - height) / 2;
// 基于压缩后的图片及宽高并进行规整
graph.drawImage(srcLogoImage, x, y, width, height, null);
Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
graph.setStroke(new BasicStroke(3f));
graph.draw(shape);
graph.dispose();
}
public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
BufferedImage image = createImage(content, imgPath, needCompress);
return image;
}
private static void mkdirs(String destPath) {
File file = new File(destPath);
// String fileName = new Random().nextInt(99999999)+".jpg";
// 当文件夹不存在时，mkdirs会自动创建多层目录，
// 区别于mkdir．(mkdir如果父目录不存在则会抛出异常)
if (!file.exists() && !file.isDirectory()) {
file.mkdirs();
}
}
public static void create(String content, String imgPath, String destPath) throws Exception {
create(content, imgPath, destPath, false);
}
// 被注释的方法
/*
* public static void encode(String content, String destPath, boolean
* needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
* needCompress); }
*/
public static void create(String content, String destPath) throws Exception {
create(content, null, destPath, false);
}
public static void encode(String content, OutputStream output) throws Exception {
encode(content, null, output, false);
}
public static void main(String[] args) {
// 存放在二维码中的内容,二维码中的内容可以是文字，可以是链接等
String srcLinkText = "http://www.baidu.com";
// 嵌入二维码的图片路径
String srcLogoImgPath = ConstVarManager.MyUploadFile_Name + "tiger1.jpeg";
// 生成的二维码的路径及名称
long currentTimeMillis = System.currentTimeMillis();
String destPath = ConstVarManager.MyUploadFile_Name + currentTimeMillis + "." + FORMAT_NAME;
// 生成二维码
try {
create(srcLinkText, srcLogoImgPath, destPath, true);
} catch (Exception e) {
e.printStackTrace();
}
// 解析二维码
String str = null;
try {
str = decodeContent(destPath);
} catch (Exception e) {
e.printStackTrace();
}
// 打印出解析出的内容
System.out.println(str);
}
}
2.2.2BarCode2Controller
package com.kikop.controller;
import com.alibaba.fastjson.JSONObject;
import com.kikop.myconst.ConstVarManager;
import com.kikop.utils.MyQrCodeUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @author kikop
* @version 1.0
* @project myzxingdemo
* @file BarCodeController2
* @desc 基于封装的二维码生成工具类进行接口调用
* https://www.zhihu.com/tardis/sogou/art/166312687
* @date 2022/04/16
* @time 20:39
* @by IDE: IntelliJ IDEA
*/
@RestController
@RequestMapping("/qrcode")
public class BarCode2Controller {
private final static String qrcodeName = "myqrcode";
/**
* autoShowOnCreate1
*
* @param request
* @return
*/
@GetMapping("/autoShowOnCreate1")
public void autoShowOnCreate1(HttpServletRequest request, HttpServletResponse response) {
try {
JSONObject result = new JSONObject();
result.put("success", true);
final String type = "." + MyQrCodeUtils.FORMAT_NAME;
String myqrcodeName = qrcodeName + type;
final String content = "http://www.baidu.com";
String destPath = ConstVarManager.MyUploadFile_Name + qrcodeName + type;
MyQrCodeUtils.create(content, null, destPath, true);
// 重定向页面
response.sendRedirect("/qrcode/home?barname=yyds&barurl=" + "/myuploadfile/" + myqrcodeName);
} catch (Exception ex) {
ex.printStackTrace();
}
}
/**
* createfail
* 无法重定向
* 原因,类中有 @RestController注解
*
* @param request
* @return
*/
@GetMapping("/createfail")
public String createfail(HttpServletRequest request, HttpServletResponse response) {
try {
JSONObject result = new JSONObject();
result.put("success", true);
final String type = "." + MyQrCodeUtils.FORMAT_NAME;
final String content = "http://www.baidu.com";
String destPath = ConstVarManager.MyUploadFile_Name + qrcodeName + type;
MyQrCodeUtils.create(content, null, destPath, true);
return "redirect:/qrcode/home?name=kikop";
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
/**
* autoShowOnCreate2
*
* @param request
* @return
*/
@GetMapping("/autoShowOnCreate2")
public ModelAndView autoShowOnCreate2(HttpServletRequest request, HttpServletResponse response, RedirectAttributes redirectAttributes) {
try {
JSONObject result = new JSONObject();
result.put("success", true);
final String type = "." + MyQrCodeUtils.FORMAT_NAME;
final String content = "http://www.baidu.com";
String myqrcodeName = qrcodeName + type;
String destPath = ConstVarManager.MyUploadFile_Name + myqrcodeName;
MyQrCodeUtils.create(content, null, destPath, true);
// 重定向页面
// 解决中文乱码
redirectAttributes.addAttribute("barname", "yyds");
redirectAttributes.addAttribute("barurl", "/myuploadfile/" + myqrcodeName);
return new ModelAndView("redirect:/qrcode/home");
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
}
2.2.3HomeController
package com.kikop.controller;
import com.alibaba.fastjson.JSONObject;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.Result;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.HybridBinarizer;
import com.kikop.myconst.CommonResponse;
import com.kikop.myconst.ConstVarManager;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.HashMap;
/**
* @author kikop
* @version 1.0
* @project myzxingdemo
* @file FileController
* @desc
* @date 2022/04/13
* @time 20:39
* @by IDE: IntelliJ IDEA
*/
@Controller
@RequestMapping("/qrcode")
public class HomeController {
private final static String qrcodeName = "myqrcode";
@GetMapping("/home")
public ModelAndView home(HttpServletRequest request) {
ModelAndView modelAndView = new ModelAndView();
modelAndView.setViewName("home");
String barname = request.getParameter("barname");
String barurl = request.getParameter("barurl");
if (null != barname && null != barurl) {
modelAndView.addObject("barname", barname);
modelAndView.addObject("barurl", barurl);
} else {
modelAndView.addObject("barname", "yyds");
// 重点:要加斜杠
modelAndView.addObject("barurl", "/myuploadfile/myqrcode.jpeg");
}
return modelAndView;
}
/**
* show
* 返回二维码中的内容
*
* @param request
* @return
*/
@GetMapping("/show")
@ResponseBody
public JSONObject show(HttpServletRequest request) {
try {
JSONObject result = new JSONObject();
result.put("success", true);
final String type = "jpeg";
MultiFormatReader multiFormatReader = new MultiFormatReader();
String destPath = ConstVarManager.MyUploadFile_Name + qrcodeName + "." + type;
File file = new File(destPath);
// 构造 bufferedImage
BufferedImage bufferedImage = ImageIO.read(file);
// 构造二进制位图
BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(bufferedImage)));
// 构建二维码参数
HashMap barcodeParam = new HashMap();
barcodeParam.put(EncodeHintType.CHARACTER_SET, "utf-8");
// 解码二进制位图
Result decodeResult = multiFormatReader.decode(binaryBitmap, barcodeParam);
result.put("parseresult", decodeResult.toString());
result.put("txt", decodeResult.getText());
result.put("format", decodeResult.getBarcodeFormat());
return result;
} catch (Exception ex) {
ex.printStackTrace();
return CommonResponse.getCommonResponse(ex);
}
}
}
2.2.4WebAppConfig
package com.kikop.config;
import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
import com.kikop.myconst.ConstVarManager;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import java.util.List;
/**
* @author kikop
* @version 1.0
* @project myantbackdemo
* @file
* @desc
* @date 2020/10/31
* @time 21:56
* @by IDE: IntelliJ IDEA
*/
@Configuration
public class WebAppConfig implements WebMvcConfigurer {
private static final String[] CLASSPATH_RESOURCE_LOCATIONS = {
"classpath:/META-INF/resources/",
"classpath:/resources/",
"classpath:/static/",
"classpath:/public/"};
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter();
converters.add(fastJsonHttpMessageConverter);
}
/**
* 静态资源(不需要,用默认的即可)
* 配置请求的解析映射路径
*
* @param registry
*/
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
// 1.默认不配置也行
// spring mvc默认的
// http://localhost:8080/myveuback.jpeg
registry.addResourceHandler("/**").addResourceLocations(CLASSPATH_RESOURCE_LOCATIONS);
// 2.自定义
registry.addResourceHandler("/myuploadfile/**")
.addResourceLocations(ConstVarManager.MyUploadFile_Protocol+ConstVarManager.MyUploadFile_Name);
}
}
2.2.5ConstVarManager
package com.kikop.myconst;
import java.io.File;
public class ConstVarManager {
public static final String MyUploadFile_Protocol = "file:///";
public static final String MyUploadFile_VisitName = "myuploadfile";
// C:\Users\kikop/myuploadfile/
public static final String MyUploadFile_Name = System.getProperties().getProperty("user.home") + File.separator +
MyUploadFile_VisitName + File.separator;
static {
// 自动创建目录判断
// https://www.cnblogs.com/qbdj/p/10980840.html
File uploadDirectory = new File(MyUploadFile_Name);
if (!uploadDirectory.exists()) {
uploadDirectory.mkdir();
// uploadDirectory.mkdirs(); //多层目录需要调用mkdirs
}
}
}
2.3前台
2.3.1home.html
<!DOCTYPE html>
<!--<html lang="en">-->
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>二维码显示</title>
</head>
<body>
<div align="center" style="width:100%;">
<div>
<span th:text="${barname}" style="font-size: 30px;"></span>
</div>
<div>
<!--<img src="http://localhost:8086/myuploadfile/myqrcode.png">-->
<!--动态获取图片的url-->
<img th:src="${barurl}">
</div>
<button onclick="getBarCodeContent()">显示二维码内容</button>
</div>
<!--懒得用thymeleaf的语法来传参数-->
<!--必须这样写:-->
<!--重点要加斜杠-->
<!--http://localhost:8086/js/jquery/jquery_1.12.4.min.js-->
<script type="text/javascript" src="/js/jquery/jquery_1.12.4.min.js"></script>
<script type="text/javascript">
function getBarCodeContent() {
var url = "/qrcode/show";
$.get(url, function (data) {
alert(data.txt);
})
}
</script>
</body>
</html>
