Java实现二维码QRCode的编码和解码

周末试用下Android手机的二维码扫描软件，扫描了下火车票、名片等等，觉得非常不错很有意思的。当然Java也可以实现这些，现在就分享下如何简单用Java实现二维码中QRCode的编码和解码（可以手机扫描验证）。

涉及到的一些主要类库，方便大家下载：

编码 lib：Qrcode_swetake.jar （官网介绍 -- http://www.swetake.com/qr/index-e.html）
解码 lib：qrcode.jar （官网介绍 -- http://sourceforge.jp/projects/qrcode/）

【一】、编码：

QRCodeEncoderHandler.java

 1 package michael.qrcode;
 2 
 3 import java.awt.Color;
 4 import java.awt.Graphics2D;
 5 import java.awt.image.BufferedImage;
 6 import java.io.File;
 7 
 8 import javax.imageio.ImageIO;
 9 
10 import com.swetake.util.Qrcode;
11 
12 /**
13  * 二维码生成器
14  * @blog http://sjsky.iteye.com
15  * @author Michael
16  */
17 public class QRCodeEncoderHandler {
18 
19     /**
20      * 生成二维码(QRCode)图片
21      * @param content
22      * @param imgPath
23      */
24     public void encoderQRCode(String content, String imgPath) {
25         try {
26 
27             Qrcode qrcodeHandler = new Qrcode();
28             qrcodeHandler.setQrcodeErrorCorrect('M');
29             qrcodeHandler.setQrcodeEncodeMode('B');
30             qrcodeHandler.setQrcodeVersion(7);
31 
32             System.out.println(content);
33             byte[] contentBytes = content.getBytes("gb2312");
34 
35             BufferedImage bufImg = new BufferedImage(140, 140,
36                     BufferedImage.TYPE_INT_RGB);
37 
38             Graphics2D gs = bufImg.createGraphics();
39 
40             gs.setBackground(Color.WHITE);
41             gs.clearRect(0, 0, 140, 140);
42 
43             // 设定图像颜色 > BLACK
44             gs.setColor(Color.BLACK);
45 
46             // 设置偏移量 不设置可能导致解析出错
47             int pixoff = 2;
48             // 输出内容 > 二维码
49             if (contentBytes.length > 0 && contentBytes.length < 120) {
50                 boolean[][] codeOut = qrcodeHandler.calQrcode(contentBytes);
51                 for (int i = 0; i < codeOut.length; i++) {
52                     for (int j = 0; j < codeOut.length; j++) {
53                         if (codeOut[j][i]) {
54                             gs.fillRect(j * 3 + pixoff, i * 3 + pixoff, 3, 3);
55                         }
56                     }
57                 }
58             } else {
59                 System.err.println("QRCode content bytes length = "
60                         + contentBytes.length + " not in [ 0,120 ]. ");
61             }
62 
63             gs.dispose();
64             bufImg.flush();
65 
66             File imgFile = new File(imgPath);
67 
68             // 生成二维码QRCode图片
69             ImageIO.write(bufImg, "png", imgFile);
70 
71         } catch (Exception e) {
72             e.printStackTrace();
73         }
74 
75     }
76 
77     /**
78      * @param args the command line arguments
79      */
80     public static void main(String[] args) {
81         String imgPath = "D:/test/twocode/Michael_QRCode.png";
82 
83         String content = "Hello 大大、小小,welcome to QRCode!"
84                 + "\nMyblog [ http://sjsky.iteye.com ]"
85                 + "\nEMail [ sjsky007@gmail.com ]" + "\nTwitter [ @suncto ]";
86 
87         QRCodeEncoderHandler handler = new QRCodeEncoderHandler();
88         handler.encoderQRCode(content, imgPath);
89 
90         System.out.println("encoder QRcode success");
91     }
92 }

【二】、解码：
QRCodeDecoderHandler.java

 1 package michael.qrcode;
 2 
 3 import java.awt.image.BufferedImage;
 4 import java.io.File;
 5 import java.io.IOException;
 6 
 7 import javax.imageio.ImageIO;
 8 
 9 import jp.sourceforge.qrcode.QRCodeDecoder;
10 import jp.sourceforge.qrcode.data.QRCodeImage;
11 import jp.sourceforge.qrcode.exception.DecodingFailedException;
12 
13 /**
14  * @blog http://sjsky.iteye.com
15  * @author Michael
16  */
17 public class QRCodeDecoderHandler {
18 
19     /**
20      * 解码二维码
21      * @param imgPath
22      * @return String
23      */
24     public String decoderQRCode(String imgPath) {
25 
26         // QRCode 二维码图片的文件
27         File imageFile = new File(imgPath);
28 
29         BufferedImage bufImg = null;
30         String decodedData = null;
31         try {
32             bufImg = ImageIO.read(imageFile);
33 
34             QRCodeDecoder decoder = new QRCodeDecoder();
35             decodedData = new String(decoder.decode(new J2SEImage(bufImg)));
36 
37             // try {
38             // System.out.println(new String(decodedData.getBytes("gb2312"),
39             // "gb2312"));
40             // } catch (Exception e) {
41             // // TODO: handle exception
42             // }
43         } catch (IOException e) {
44             System.out.println("Error: " + e.getMessage());
45             e.printStackTrace();
46         } catch (DecodingFailedException dfe) {
47             System.out.println("Error: " + dfe.getMessage());
48             dfe.printStackTrace();
49         }
50         return decodedData;
51     }
52 
53     /**
54      * @param args the command line arguments
55      */
56     public static void main(String[] args) {
57         QRCodeDecoderHandler handler = new QRCodeDecoderHandler();
58         String imgPath = "d:/test/twocode/Michael_QRCode.png";
59         String decoderContent = handler.decoderQRCode(imgPath);
60         System.out.println("解析结果如下：");
61         System.out.println(decoderContent);
62         System.out.println("========decoder success!!!");
63     }
64 
65     class J2SEImage implements QRCodeImage {
66         BufferedImage bufImg;
67 
68         public J2SEImage(BufferedImage bufImg) {
69             this.bufImg = bufImg;
70         }
71 
72         public int getWidth() {
73             return bufImg.getWidth();
74         }
75 
76         public int getHeight() {
77             return bufImg.getHeight();
78         }
79 
80         public int getPixel(int x, int y) {
81             return bufImg.getRGB(x, y);
82         }
83 
84     }
85 }

转载请注明来自：Michael's blog @ http://sjsky.iteye.com