Find QR code in image and decode it using Zxing

here is the code to create the Qr-Code and read Message from Qr-code

1. you need the build the zxing library

2. main describe the qr-code creation and qr-code extraction

   package com.attendance.mark;
   import java.io.File;
   import java.io.FileInputStream;
   import java.io.FileNotFoundException;
   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.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.WriterException;
   import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
   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;
   
   public class QRCode {
   
       /**
        * 
        * @param args 
        * @throws WriterException
        * @throws IOException
        * @throws NotFoundException
        */
     public static void main(String[] args) throws WriterException, IOException,
         NotFoundException {
       String qrCodeData = "student3232_2015_12_15_10_29_46_123";
       String filePath = "F:\\Opulent_ProjectsDirectory_2015-2016\\.metadata\\.plugins\\org.eclipse.wst.server.core\\tmp0\\wtpwebapps\\AttendanceUsingQRCode\\QRCodes\\student3232_2015_12_15_10_29_46_123";
       String charset = "UTF-8"; // or "ISO-8859-1"
       Map<EncodeHintType, ErrorCorrectionLevel> hintMap = new HashMap<EncodeHintType, ErrorCorrectionLevel>();
       hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
   
       createQRCode(qrCodeData, filePath, charset, hintMap, 200, 200);
       System.out.println("QR Code image created successfully!");
   
       System.out.println("Data read from QR Code: "
           + readQRCode(filePath, charset, hintMap));
   
     }
   
     /***
      * 
      * @param qrCodeData
      * @param filePath
      * @param charset
      * @param hintMap
      * @param qrCodeheight
      * @param qrCodewidth
      * @throws WriterException
      * @throws IOException
      */
     public static void createQRCode(String qrCodeData, String filePath,
         String charset, Map hintMap, int qrCodeheight, int qrCodewidth)
         throws WriterException, IOException {
       BitMatrix matrix = new MultiFormatWriter().encode(
           new String(qrCodeData.getBytes(charset), charset),
           BarcodeFormat.QR_CODE, qrCodewidth, qrCodeheight);
       MatrixToImageWriter.writeToFile(matrix, filePath.substring(filePath
           .lastIndexOf('.') + 1), new File(filePath));
     }
   
     /**
      * 
      * @param filePath
      * @param charset
      * @param hintMap
      * 
      * @return Qr Code value 
      * 
      * @throws FileNotFoundException
      * @throws IOException
      * @throws NotFoundException
      */
     public static String readQRCode(String filePath, String charset, Map hintMap)
         throws FileNotFoundException, IOException, NotFoundException {
       BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(
           new BufferedImageLuminanceSource(
               ImageIO.read(new FileInputStream(filePath)))));
       Result qrCodeResult = new MultiFormatReader().decode(binaryBitmap, hintMap);
       return qrCodeResult.getText();
     }
   }