Java利用zxing生成/解析二维码

QRCode：全称Quick Response Code ，是二维码的一种

参考博客 http://www.cnblogs.com/jtmjx/archive/2012/06/18/2545209.html
慕课网视频 生成二维码 http://www.imooc.com/video/10315
慕课网视频 解析二维码 http://www.imooc.com/video/10316

第1步.引入jar包
源码路径 https://github.com/zxing/zxing/releases
没有现成的jar包，可以根据源码，自己建java project项目，把源码拷贝到项目中，然后导出jar包
导出jar包的时候，可能有错误，忽略

2. 编写生成二维码的实现代码

import java.io.File;import java.nio.file.Path;import java.util.HashMap;import java.util.Map;import com.google.zxing.BarcodeFormat;import com.google.zxing.EncodeHintType;import com.google.zxing.MultiFormatWriter;import com.google.zxing.client.j2se.MatrixToImageWriter;import com.google.zxing.common.BitMatrix;import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;public class CreateQRCode {    public static void main(String[] args) {        /*定义二维码参数*/         String content = "https://github.com/zxing/zxing/releases";// 二维码内容        Map hints = new HashMap();        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);// 纠错等级        hints.put(EncodeHintType.MARGIN, 2);// 边距，默认是5        /*生成二维码*/         try {            MultiFormatWriter multiFormatWriter = new MultiFormatWriter();                      /*二维码类型QR_CODE，是图片宽度和高度是300*300*/             BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 300, 300, hints);            Path path = new File("C:/Users/Administrator/Desktop/img.png").toPath();// 二维码存放的路径和名称            MatrixToImageWriter.writeToPath(bitMatrix, "png", path);//图片是png类型        } catch (Exception e) {            e.printStackTrace();        }    }}

纠错能力越高，存储的数据越少，对二维码的清晰度要求越低。
L级：可纠错7%的数据码字 M:15% Q:25% H:30%

除了zxing, javascript，jquery.qrcode.js也可以生成二维码

3. 编写解析二维码的实现代码

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.BinaryBitmap;import com.google.zxing.EncodeHintType;import com.google.zxing.MultiFormatReader;import com.google.zxing.NotFoundException;import com.google.zxing.Result;import com.google.zxing.client.j2se.BufferedImageLuminanceSource;import com.google.zxing.common.HybridBinarizer;public class ReadQRCode {    public static void main(String[] args) throws IOException, NotFoundException {        MultiFormatReader formatReader = new MultiFormatReader();        File file = new File("C:/Users/Administrator/Desktop/img.png");             BufferedImage image = ImageIO.read(file);        BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(image)));        Map hints = new HashMap();        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");        Result result = formatReader.decode(binaryBitmap,hints);        System.out.println("解析结果:"+result.toString());        System.out.println("二维码格式:"+result.getBarcodeFormat());        System.out.println("二维码文本内容:"+result.getText());    }}