Java二维码的生成与下载

忘是亡心i 2022-05-11 12:08 376阅读 0赞

> **1.新增Maven项目（spring-boot项目），pom加入如下：**
> 
>     <parent>
>     		<groupId>org.springframework.boot</groupId>
>     		<artifactId>spring-boot-starter-parent</artifactId>
>     		<version>2.0.2.RELEASE</version>
>     		<relativePath /> 
>     	</parent>
>     
>     	<properties>
>     		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
>     		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
>     		<java.version>1.8</java.version>
>     	</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-starter-tomcat</artifactId>
>     		</dependency>
>     		<dependency>
>     			<groupId>org.apache.tomcat.embed</groupId>
>     			<artifactId>tomcat-embed-jasper</artifactId>
>     		</dependency>
>     
>     						
>     		<dependency>
>     			<groupId>org.springframework.boot</groupId>
>     			<artifactId>spring-boot-devtools</artifactId>
>     			<optional>true</optional>
>     		</dependency>
>     		
>     		
>     		<dependency>
>     			<groupId>com.google.zxing</groupId>
>     			<artifactId>core</artifactId>
>     			<version>3.3.3</version>
>     		</dependency>
>     
>     		
>     		<dependency>
>     			<groupId>com.google.zxing</groupId>
>     			<artifactId>javase</artifactId>
>     			<version>3.3.3</version>
>     		</dependency>
>     
>     	</dependencies>
>     
>     	<build>
>     		<plugins>
>     			<plugin>
>     				<groupId>org.springframework.boot</groupId>
>     				<artifactId>spring-boot-maven-plugin</artifactId>
>     			</plugin>
>     		</plugins>
>     	</build>
> 
>

**2，加入如下工具类：**

import java.awt.Graphics2D;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.Map;
    
    import javax.imageio.ImageIO;
    
    import com.google.zxing.BarcodeFormat;
    import com.google.zxing.BinaryBitmap;
    import com.google.zxing.DecodeHintType;
    import com.google.zxing.EncodeHintType;
    import com.google.zxing.MultiFormatReader;
    import com.google.zxing.MultiFormatWriter;
    import com.google.zxing.NotFoundException;
    import com.google.zxing.Result;
    import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
    import com.google.zxing.client.j2se.MatrixToImageConfig;
    import com.google.zxing.client.j2se.MatrixToImageWriter;
    import com.google.zxing.common.BitMatrix;
    import com.google.zxing.common.HybridBinarizer;
    import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;  
      
    /** 
     * ZXing工具类 
     * @see ----------------------------------------------------------------------------------------------------------------------- 
     * @see 首页--https://code.google.com/p/zxing 
     * @see 介绍--用于解析多种格式条形码(EAN-13)和二维码(QRCode)的开源Java类库,其提供了多种应用的类库,如javase/jruby/cpp/csharp/android 
     * @see 说明--下载到的ZXing-2.2.zip是它的源码,我们在JavaSE中使用时需用到其core和javase两部分 
     * @see      可直接引入它俩的源码到项目中,或将它俩编译为jar再引入,这是我编译好的：http://download.csdn.net/detail/jadyer/6245849 
     * @see ----------------------------------------------------------------------------------------------------------------------- 
     * @see 经测试:用微信扫描GBK编码的中文二维码时出现乱码,用UTF-8编码时微信可正常识别 
     * @see       并且MultiFormatWriter.encode()时若传入hints参数来指定UTF-8编码中文时,微信压根就不识别所生成的二维码 
     * @see       所以这里使用的是这种方式new String(content.getBytes("UTF-8"), "ISO-8859-1") 
     * @see ----------------------------------------------------------------------------------------------------------------------- 
     * @see 将logo图片加入二维码中间时,需注意以下几点 
     * @see 1)生成二维码的纠错级别建议采用最高等级H,这样可以增加二维码的正确识别能力(我测试过,不设置级别时,二维码工具无法读取生成的二维码图片) 
     * @see 2)头像大小最好不要超过二维码本身大小的1/5,而且只能放在正中间部位,这是由于二维码本身结构造成的(你就把它理解成图片水印吧) 
     * @see 3)在仿照腾讯微信在二维码四周增加装饰框,那么一定要在装饰框和二维码之间留出白边,这是为了二维码可被识别 
     * @see ----------------------------------------------------------------------------------------------------------------------- 
     * @version v1.0 
     * @history v1.0-->方法新建,目前仅支持二维码的生成和解析,生成二维码时支持添加logo头像 
     * @editor Sep 10, 2013 9:32:23 PM 
     * @create Sep 10, 2013 2:08:16 PM 
     * @author 玄玉<http://blog.csdn.net/jadyer> 
     */  
    public class ZixingCode {  
          
        /** 
         * 生成二维码 
         * @param content   二维码内容 
         * @param charset   编码二维码内容时采用的字符集(传null时默认采用UTF-8编码) 
         * @param imagePath 二维码图片存放路径(含文件名) 
         * @param width     生成的二维码图片宽度 
         * @param height    生成的二维码图片高度 
         * @param logoPath  logo头像存放路径(含文件名,若不加logo则传null即可) 
         * @return 生成二维码结果(true or false) 
         */  
    	public static boolean encodeQRCodeImage(String content, String charset, String imagePath, int width, int height,
    			String logoPath) {
    		Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
    		// 指定编码格式
    		// hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    		// 指定纠错级别(L--7%,M--15%,Q--25%,H--30%)
    		hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
    		// 编码内容,编码类型(这里指定为二维码),生成图片宽度,生成图片高度,设置参数
    		BitMatrix bitMatrix = null;
    		try {
    			bitMatrix = new MultiFormatWriter().encode(
    					new String(content.getBytes(charset == null ? "UTF-8" : charset), "ISO-8859-1"),
    					BarcodeFormat.QR_CODE, width, height, hints);
    		} catch (Exception e) {
    			System.out.println("编码待生成二维码图片的文本时发生异常,堆栈轨迹如下");
    			e.printStackTrace();
    			return false;
    		}
    		
    		// 生成的二维码图片默认背景为白色,前景为黑色,但是在加入logo图像后会导致logo也变为黑白色,至于是什么原因还没有仔细去读它的源码
    		// 所以这里对其第一个参数黑色将ZXing默认的前景色0xFF000000稍微改了一下0xFF000001,最终效果也是白色背景黑色前景的二维码,且logo颜色保持原有不变
    		MatrixToImageConfig config = new MatrixToImageConfig(0xFF000001, 0xFFFFFFFF);
    		// 这里要显式指定MatrixToImageConfig,否则还会按照默认处理将logo图像也变为黑白色(如果打算加logo的话,反之则不须传MatrixToImageConfig参数)
    		try {
    			MatrixToImageWriter.writeToFile(bitMatrix, imagePath.substring(imagePath.lastIndexOf(".") + 1),
    					new File(imagePath), config);
    		} catch (IOException e) {
    			System.out.println("生成二维码图片[" + imagePath + "]时遇到异常,堆栈轨迹如下");
    			e.printStackTrace();
    			return false;
    		}
    		
    		// 此时二维码图片已经生成了,只不过没有logo头像,所以接下来根据传入的logoPath参数来决定是否加logo头像
    		if (null == logoPath) {
    			return true;
    		} else {
    			// 如果此时最终生成的二维码不是我们想要的,那么可以扩展MatrixToImageConfig类(反正ZXing提供了源码)
    			// 扩展时可以重写其writeToFile方法,令其返回toBufferedImage()方法所生成的BufferedImage对象(尽管这种做法未必能解决为题,故需根据实际情景测试)
    			// 然后替换这里overlapImage()里面的第一行BufferedImage image = ImageIO.read(new
    			// File(imagePath));
    			// 即private static void overlapImage(BufferedImage image, String imagePath,
    			// String logoPath)
    			try {
    				// 这里不需要判断logoPath是否指向了一个具体的文件,因为这种情景下overlapImage会抛IO异常
    				overlapImage(imagePath, logoPath);
    				return true;
    			} catch (IOException e) {
    				System.out.println("为二维码图片[" + imagePath + "]添加logo头像[" + logoPath + "]时遇到异常,堆栈轨迹如下");
    				e.printStackTrace();
    				return false;
    			}
    		}
    	}
        
        /** 
         * 为二维码图片增加logo头像 
         * @see 其原理类似于图片加水印 
         * @param imagePath 二维码图片存放路径(含文件名) 
         * @param logoPath  logo头像存放路径(含文件名) 
         */  
    	private static void overlapImage(String imagePath, String logoPath) throws IOException {
    		BufferedImage image = ImageIO.read(new File(imagePath));
    		int logoWidth = image.getWidth() / 5; // 设置logo图片宽度为二维码图片的五分之一
    		int logoHeight = image.getHeight() / 5; // 设置logo图片高度为二维码图片的五分之一
    		int logoX = (image.getWidth() - logoWidth) / 2; // 设置logo图片的位置,这里令其居中
    		int logoY = (image.getHeight() - logoHeight) / 2; // 设置logo图片的位置,这里令其居中
    		Graphics2D graphics = image.createGraphics();
    		graphics.drawImage(ImageIO.read(new File(logoPath)), logoX, logoY, logoWidth, logoHeight, null);
    		graphics.dispose();
    		ImageIO.write(image, imagePath.substring(imagePath.lastIndexOf(".") + 1), new File(imagePath));
    	}
          
        /** 
         * 解析二维码 
         * @param imagePath 二维码图片存放路径(含文件名) 
         * @param charset   解码二维码内容时采用的字符集(传null时默认采用UTF-8编码) 
         * @return 解析成功后返回二维码文本,否则返回空字符串 
         */  
    	public static String decodeQRCodeImage(String imagePath, String charset) {
    		BufferedImage image = null;
    		try {
    			image = ImageIO.read(new File(imagePath));
    		} catch (IOException e) {
    			e.printStackTrace();
    			return "";
    		}
    		if (null == image) {
    			System.out.println("Could not decode QRCodeImage");
    			return "";
    		}
    		BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(image)));
    		Map<DecodeHintType, String> hints = new HashMap<DecodeHintType, String>();
    		hints.put(DecodeHintType.CHARACTER_SET, charset == null ? "UTF-8" : charset);
    		Result result = null;
    		try {
    			result = new MultiFormatReader().decode(bitmap, hints);
    			return result.getText();
    		} catch (NotFoundException e) {
    			System.out.println("二维码图片[" + imagePath + "]解析失败,堆栈轨迹如下");
    			e.printStackTrace();
    			return "";
    		}
    	}
        
    	public static void main(String[] args) {
    		String text ="二维码名片：\n姓名：张三"
    				+ "\n邮箱：729754701@qq.com";
    		String imagePath ="D:/二维码.png";
    		String logoPath = "D:/test.jpg";
    		ZixingCode.encodeQRCodeImage(text, null, imagePath, 800, 800, logoPath);
    		
    		
    		String decodeString = decodeQRCodeImage(imagePath, null);
    		System.out.println(decodeString);
    	}
    
        
    }

** 3.application.yml加入配置：**

server:
      port: 8800
      
    spring:
      mvc:
        view:
          prefix: /WEB-INF/jsp/
          suffix: .jsp

4.新建QrcodeController：

import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.IOException;
    import java.io.OutputStream;
    
    import javax.imageio.ImageIO;
    import javax.imageio.stream.FileImageInputStream;
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    import com.itmayiedu.util.ZixingCode;
    
    @Controller
    public class QrCodeController {
    	
    	@RequestMapping("/index")
    	public String index () {
    		return "index";
    	}
    	
    	@RequestMapping("/download")
    	public void download (HttpServletRequest request, HttpServletResponse response) {
    		//String url = request.getParameter("pictureUrl");
    		String url = "D:/二维码.png";
    		//获取文件
    		File file = new File(url);
    		//将图片读成二进制流
    		FileImageInputStream inputStream = null;
    		OutputStream outputStream = null;
    
    		try {
    			inputStream = new FileImageInputStream (file);
    			outputStream = response.getOutputStream();
    			
    			/*byte b [] = new byte[1024];
    			int len = -1;
    			while ((len = inputStream.read(b)) != -1) {
    				outputStream.write(b, 0, len);
    			}*/
    			int streamLength = (int) inputStream.length();
    			byte[] image = new byte[streamLength ];
    			inputStream.read(image, 0, streamLength );
    
    			response.setHeader("Content-Type", "application/octet-stream");
    			response.setHeader("Content-Disposition", "attachment;filename=" + "aa.png");
    			outputStream.write(image);
    			outputStream.flush();
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			try {
    				inputStream.close();
    				outputStream.close();
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    		}
    
    	}
    	
    	@RequestMapping("/getQrcode")
    	public void service(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    		String text ="二维码名片：\n姓名：王稀\nQQ：851372808"
    				+ "\n电话：18995699027\n邮箱：qqicq2001@163.com\n博客：http://blog.csdn.net/qqicq2001";
    		
    		String imagePath ="D:/二维码.png";
    		String logoPath = "D:/test.jpg";
    		ZixingCode.encodeQRCodeImage(text, null, imagePath, 800, 800,logoPath);
    		BufferedImage image =ImageIO.read(new File(imagePath));
    		ImageIO.write(image, "JPEG", response.getOutputStream());
    	}
    
    }

**5.新建src/main/webapp，该目录下新建文件夹WEB-INF，然后新建文件夹jsp**

![70][]

**在jsp下面新建index.html**

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
      <a href="download"><img alt="" src="getQrcode"></a>
    </body>
    </html>

**6.启动项目，访问：[http://127.0.0.1:8800/index][http_127.0.0.1_8800_index]即可，点击图片就可以下载**

![70 1][]

[70]: /images/20220505/0c6865cc20a1427db78e5acb96cda056.png
[http_127.0.0.1_8800_index]: http://127.0.0.1:7900/index
[70 1]: /images/20220505/ae21ce49064e41c2bdc07d582c3f0e92.png