Java implements encoding and decoding of QR code QRCode and sample analysis

Java implements the encoding and decoding of QR code QRCode

Some of the main class libraries involved are convenient for everyone to download:

Encoding lib: Qrcode_swetake.jar (Official website introduction - - http://www.swetake.com/qr/index-e.html)                                                                                                                                                                                   through

##【1】Encoding:

Java code QRCodeEncoderHandler.java

package michael.qrcode; 
  
import java.awt.Color; 
import java.awt.Graphics2D; 
import java.awt.image.BufferedImage; 
import java.io.File; 
  
import javax.imageio.ImageIO; 
  
import com.swetake.util.Qrcode; 
  
/**
 * 二维码生成器
 * @blog http://sjsky.iteye.com
 * @author Michael
 */
public class QRCodeEncoderHandler { 
  
 /**
 * 生成二维码(QRCode)图片
 * @param content
 * @param imgPath
 */
 public void encoderQRCode(String content, String imgPath) { 
 try { 
  
 Qrcode qrcodeHandler = new Qrcode(); 
 qrcodeHandler.setQrcodeErrorCorrect('M'); 
 qrcodeHandler.setQrcodeEncodeMode('B'); 
 qrcodeHandler.setQrcodeVersion(7); 
  
 System.out.println(content); 
 byte[] contentBytes = content.getBytes("gb2312"); 
  
 BufferedImage bufImg = new BufferedImage(140, 140, 
  BufferedImage.TYPE_INT_RGB); 
  
 Graphics2D gs = bufImg.createGraphics(); 
  
 gs.setBackground(Color.WHITE); 
 gs.clearRect(0, 0, 140, 140); 
  
 // 设定图像颜色> BLACK 
 gs.setColor(Color.BLACK); 
  
 // 设置偏移量 不设置可能导致解析出错 
 int pixoff = 2; 
 // 输出内容> 二维码 
 if (contentBytes.length > 0 && contentBytes.length < 120) { 
 boolean[][] codeOut = qrcodeHandler.calQrcode(contentBytes); 
 for (int i = 0; i < codeOut.length; i++) { 
  for (int j = 0; j < codeOut.length; j++) { 
  if (codeOut[j][i]) { 
  gs.fillRect(j * 3 + pixoff, i * 3 + pixoff, 3, 3); 
  } 
  } 
 } 
 } else { 
 System.err.println("QRCode content bytes length = "
  + contentBytes.length + " not in [ 0,120 ]. "); 
 } 
  
 gs.dispose(); 
 bufImg.flush(); 
  
 File imgFile = new File(imgPath); 
  
 // 生成二维码QRCode图片 
 ImageIO.write(bufImg, "png", imgFile); 
  
 } catch (Exception e) { 
 e.printStackTrace(); 
 } 
  
 } 
  
 /**
 * @param args the command line arguments
 */
 public static void main(String[] args) { 
 String imgPath = "D:/test/twocode/Michael_QRCode.png"; 
  
 String content = "Hello 大大、小小,welcome to QRCode!"
 + "\nMyblog [ http://sjsky.iteye.com ]"
 + "\nEMail [ sjsky007@gmail.com ]" + "\nTwitter [ @suncto ]"; 
  
 QRCodeEncoderHandler handler = new QRCodeEncoderHandler(); 
 handler.encoderQRCode(content, imgPath); 
  
 System.out.println("encoder QRcode success"); 
 } 
}

The QR code image generated after running is as follows:

At this time, you can use the QR code scanning software of your mobile phone (I use: android snapshot QR code) to test it. The screenshot of successful recognition is as follows:

Friends who like it can download it and give it a try, and make some business cards or things you like. Of course, Java can also decode QR code images. For details, see the content about decoding below.

【2】. Decoding:

Java code QRCodeDecoderHandler.java

package michael.qrcode; 
  
import java.awt.image.BufferedImage; 
import java.io.File; 
import java.io.IOException; 
  
import javax.imageio.ImageIO; 
  
import jp.sourceforge.qrcode.QRCodeDecoder; 
import jp.sourceforge.qrcode.data.QRCodeImage; 
import jp.sourceforge.qrcode.exception.DecodingFailedException; 
  
/**
 * @blog http://sjsky.iteye.com
 * @author Michael
 */
public class QRCodeDecoderHandler { 
  
 /**
 * 解码二维码
 * @param imgPath
 * @return String
 */
 public String decoderQRCode(String imgPath) { 
  
 // QRCode 二维码图片的文件 
 File imageFile = new File(imgPath); 
  
 BufferedImage bufImg = null; 
 String decodedData = null; 
 try { 
 bufImg = ImageIO.read(imageFile); 
  
 QRCodeDecoder decoder = new QRCodeDecoder(); 
 decodedData = new String(decoder.decode(new J2SEImage(bufImg))); 
  
 // try { 
 // System.out.println(new String(decodedData.getBytes("gb2312"), 
 // "gb2312")); 
 // } catch (Exception e) { 
 // // TODO: handle exception 
 // } 
 } catch (IOException e) { 
 System.out.println("Error: " + e.getMessage()); 
 e.printStackTrace(); 
 } catch (DecodingFailedException dfe) { 
 System.out.println("Error: " + dfe.getMessage()); 
 dfe.printStackTrace(); 
 } 
 return decodedData; 
 } 
  
 /**
 * @param args the command line arguments
 */
 public static void main(String[] args) { 
 QRCodeDecoderHandler handler = new QRCodeDecoderHandler(); 
 String imgPath = "d:/test/twocode/Michael_QRCode.png"; 
 String decoderContent = handler.decoderQRCode(imgPath); 
 System.out.println("解析结果如下："); 
 System.out.println(decoderContent); 
 System.out.println("========decoder success!!!"); 
 } 
  
 class J2SEImage implements QRCodeImage { 
 BufferedImage bufImg; 
  
 public J2SEImage(BufferedImage bufImg) { 
 this.bufImg = bufImg; 
 } 
  
 public int getWidth() { 
 return bufImg.getWidth(); 
 } 
  
 public int getHeight() { 
 return bufImg.getHeight(); 
 } 
  
 public int getPixel(int x, int y) { 
 return bufImg.getRGB(x, y); 
 } 
  
 } 
}

The running results are as follows (the decoded content is consistent with the previously entered content):

The analysis results are as follows:

Hello big, small, welcome to QRCode!

Myblog [ http://sjsky.iteye.com ]

EMail [ sjsky007@ gmail.com ]

Twitter [ @suncto ]

========decoder success!!!

The above is the implementation of QR code QRCode in Java The encoding and decoding information has been compiled, and relevant information will be added in the future. Thank you for your support of this site!

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