项目源代码：qrcode
主要需要zxing的core-3.2.1.jar以及javase-3.2.1.jar包。

但是有一个问题就是zxing.3.2.1版本是Java1.7编译的，所以如果我们需要java1.6以及以下版本兼容的话，可以使用如下代码：

这个版本的zxing.jar包：[http://pan.baidu.com/s/1c1a4f6K]

package hp.test;

import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;

import javax.imageio.ImageIO;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Base64OutputStream;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
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.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class QRCodeKit {
    
    public static final String QRCODE_DEFAULT_CHARSET = "UTF-8";

    public static final int QRCODE_DEFAULT_HEIGHT = 150;

    public static final int QRCODE_DEFAULT_WIDTH = 150;
    
    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;
    
    public static void main(String[] args) throws IOException, NotFoundException{
        String data = "http://www.baidu.com";
        File logoFile = new File("logo.png");
        BufferedImage image = QRCodeKit.createQRCodeWithLogo(data, logoFile);
        ImageIO.write(image, "png", new File("result7.png"));
        System.out.println("done");
    }

    /**
     * Create qrcode with default settings
     *
     * @author stefli
     * @param data
     * @return
     */
    public static BufferedImage createQRCode(String data) {
        return createQRCode(data, QRCODE_DEFAULT_WIDTH, QRCODE_DEFAULT_HEIGHT);
    }

    /**
     * Create qrcode with default charset
     *
     * @author stefli
     * @param data
     * @param width
     * @param height
     * @return
     */
    public static BufferedImage createQRCode(String data, int width, int height) {
        return createQRCode(data, QRCODE_DEFAULT_CHARSET, width, height);
    }

    /**
     * Create qrcode with specified charset
     *
     * @author stefli
     * @param data
     * @param charset
     * @param width
     * @param height
     * @return
     */
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static BufferedImage createQRCode(String data, String charset, int width, int height) {
        Map hint = new HashMap();
        hint.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hint.put(EncodeHintType.CHARACTER_SET, charset);

        return createQRCode(data, charset, hint, width, height);
    }

    /**
     * Create qrcode with specified hint
     *
     * @author stefli
     * @param data
     * @param charset
     * @param hint
     * @param width
     * @param height
     * @return
     */
    public static BufferedImage createQRCode(String data, String charset, Map<EncodeHintType, ?> hint, int width,
            int height) {
        BitMatrix matrix;
        try {
            matrix = new MultiFormatWriter().encode(new String(data.getBytes(charset), charset), BarcodeFormat.QR_CODE,
                    width, height, hint);
            return toBufferedImage(matrix);
        } catch (WriterException e) {
            throw new RuntimeException(e.getMessage(), e);
        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }
    public 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;
    }
    /**
     * Create qrcode with default settings and logo
     *
     * @author stefli
     * @param data
     * @param logoFile
     * @return
     */
    public static BufferedImage createQRCodeWithLogo(String data, File logoFile) {
        return createQRCodeWithLogo(data, QRCODE_DEFAULT_WIDTH, QRCODE_DEFAULT_HEIGHT, logoFile);
    }

    /**
     * Create qrcode with default charset and logo
     *
     * @author stefli
     * @param data
     * @param width
     * @param height
     * @param logoFile
     * @return
     */
    public static BufferedImage createQRCodeWithLogo(String data, int width, int height, File logoFile) {
        return createQRCodeWithLogo(data, QRCODE_DEFAULT_CHARSET, width, height, logoFile);
    }

    /**
     * Create qrcode with specified charset and logo
     *
     * @author stefli
     * @param data
     * @param charset
     * @param width
     * @param height
     * @param logoFile
     * @return
     */
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static BufferedImage createQRCodeWithLogo(String data, String charset, int width, int height, File logoFile) {
        Map hint = new HashMap();
        hint.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hint.put(EncodeHintType.CHARACTER_SET, charset);

        return createQRCodeWithLogo(data, charset, hint, width, height, logoFile);
    }

    /**
     * Create qrcode with specified hint and logo
     *
     * @author stefli
     * @param data
     * @param charset
     * @param hint
     * @param width
     * @param height
     * @param logoFile
     * @return
     */
    public static BufferedImage createQRCodeWithLogo(String data, String charset, Map<EncodeHintType, ?> hint,
            int width, int height, File logoFile) {
        try {
            BufferedImage qrcode = createQRCode(data, charset, hint, width, height);
            BufferedImage logo = ImageIO.read(logoFile);
            int deltaHeight = height - logo.getHeight();
            int deltaWidth = width - logo.getWidth();

            BufferedImage combined = new BufferedImage(height, width, BufferedImage.TYPE_INT_ARGB);
            Graphics2D g = (Graphics2D) combined.getGraphics();
            g.drawImage(qrcode, 0, 0, null);
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 1f));
            g.drawImage(logo, (int) Math.round(deltaWidth / 2), (int) Math.round(deltaHeight / 2), null);

            return combined;
        } catch (IOException e) {
            throw new RuntimeException(e.getMessage(), e);
        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    /**
     * Return base64 for image
     *
     * @author stefli
     * @param image
     * @return
     */
    public static String getImageBase64String(BufferedImage image) {
        String result = null;
        try {
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            OutputStream b64 = new Base64OutputStream(os);
            ImageIO.write(image, "png", b64);
            result = os.toString("UTF-8");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e.getMessage(), e);
        } catch (IOException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
        return result;
    }

    /**
     * Decode the base64Image data to image
     *
     * @author stefli
     * @param base64ImageString
     * @param file
     */
    public static void convertBase64StringToImage(String base64ImageString, File file) {
        FileOutputStream os;
        try {
            Base64 d = new Base64();
            byte[] bs = d.decode(base64ImageString);
            os = new FileOutputStream(file.getAbsolutePath());
            os.write(bs);
            os.close();
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e.getMessage(), e);
        } catch (IOException e) {
            throw new RuntimeException(e.getMessage(), e);
        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }
    
    
}

done.