利用QrCode生成二维码

public class QrCodeCreateUtil {

public static null createQrCode( String content, int qrCodeSize, String imageFormat)throws WriterException, IOException{
Hashtable<EncodeHintType, ErrorCorrectionLevel> hintMap = new Hashtable<EncodeHintType, ErrorCorrectionLevel>(); 
hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);  // 矫错级别 
QRCodeWriter qrCodeWriter = new QRCodeWriter();
//创建比特矩阵(位矩阵)的QR码编码的字符串  
BitMatrix byteMatrix = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, qrCodeSize, qrCodeSize, hintMap);  
// 使BufferedImage勾画QRCode  (matrixWidth 是行二维码像素点)
int matrixWidth = byteMatrix.getWidth(); 
BufferedImage image = new BufferedImage(matrixWidth-200, matrixWidth-200, BufferedImage.TYPE_INT_RGB);
image.createGraphics();  
Graphics2D graphics = (Graphics2D) image.getGraphics();  
graphics.setColor(Color.WHITE);  
graphics.fillRect(0, 0, matrixWidth, matrixWidth); 
 
//使用比特矩阵呼出啊并保存图像
graphics.setColor(Color.BLACK);
 
for(int i=0; i<matrixWidth; i++){
for (int j=0; j<matrixWidth; j++ ){
if(byteMatrix.get(i, j)){
graphics.fillRect(i-100, j-100, 1, 1);  
}
}
}
return ImageIO.write(image, imageFormat, outputStream);
// return image;
}


public static void readQrCode(InputStream inputStream)throws IOException{
//从输入流中获取字符串信息
BufferedImage image = ImageIO.read(inputStream);
//将图像转换为二进制位图源
LuminanceSource source = new BufferedImageLuminanceSource(image);
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));  
QRCodeReader reader = new QRCodeReader();
 
Result result = null ; 
try {
result = reader.decode(bitmap);
}catch (ReaderException e){
e.printStackTrace();  
}
System.out.println(result.getText());  
}


public static void main(String[] args) throws IOException, WriterException { 
createQrCode("classid",900,"JPEG");
readQrCode(new FileInputStream(new File("d:\\qrcode.jpg")));
}
 
 
}