使用了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;
}
}
}