google zxing作为二维码生成工具

import com.google.zxing.BarcodeFormat;import com.google.zxing.EncodeHintType;import com.google.zxing.MultiFormatWriter;import com.google.zxing.common.BitMatrix;import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import javax.imageio.ImageIO;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOException;import java.util.Hashtable;import java.util.Map;public class ZxingUtils {    PRivate static Log log = LogFactory.getLog(ZxingUtils.class);    private static final int BLACK = 0xFF000000;    private static final int WHITE = 0xFFFFFFFF;    private static BufferedImage toBufferedImage(BitMatrix matrix) {        int width = matrix.getWidth();        int height = matrix.getHeight();        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);        for (int x = 0; x < width; x++) {            for (int y = 0; y < height; y++) {                image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);            }        }        return image;    }    private static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {        BufferedImage image = toBufferedImage(matrix);        if (!ImageIO.write(image, format, file)) {            throw new IOException("Could not write an image of format " + format + " to " + file);        }    }    /** 将内容contents生成长宽均为width的图片，图片路径由imgPath指定     */    public static File getQRCodeImge(String contents, int width, String imgPath) {        return getQRCodeImge(contents, width, width, imgPath);    }    /** 将内容contents生成长为width，宽为width的图片，图片路径由imgPath指定     */    public static File getQRCodeImge(String contents, int width, int height, String imgPath) {        try {            Map<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);            hints.put(EncodeHintType.CHARACTER_SET, "UTF8");            BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, BarcodeFormat.QR_CODE, width, height, hints);            File imageFile = new File(imgPath);            writeToFile(bitMatrix, "png", imageFile);            return imageFile;        } catch (Exception e) {            log.error("create QR code error!", e);            return null;        }    }}