java 通过zxing生成二维码

package com.green.util;

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;

import javax.imageio.ImageIO;

import com.google.zxing.common.BitMatrix;

public final class MatrixToImageWriter {

	private static final int BLACK = 0xFF000000;
	private static final int WHITE = 0xFFFFFFFF;

	private MatrixToImageWriter() {
	}

	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;
	}

	public 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);
		}
	}

	public static byte[] writeToStream(BitMatrix matrix, String format) throws IOException {
		ByteArrayOutputStream stream=new ByteArrayOutputStream();
		BufferedImage image = toBufferedImage(matrix);
	
		if (!ImageIO.write(image, format, stream)) {
			throw new IOException("Could not write an image of format " + format);
		}
	
		return stream.toByteArray();
	}

}

package com.green.util;

import java.io.File;
import java.io.IOException;
import java.util.Hashtable;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;

/**
 * @author maybo
 *
 */
public class QrCodeGenerator {
	public static byte[] build(String content) throws IOException, WriterException {
	        int width = 300; 
	        int height = 300; 
	        //��ά���ͼƬ��ʽ 
	        String format = "gif"; 
	        Hashtable hints = new Hashtable(); 
	        //������ʹ�ñ��� 
	        hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); 
	        BitMatrix bitMatrix = new MultiFormatWriter().encode(content, 
	                BarcodeFormat.QR_CODE, width, height, hints); 
	       return MatrixToImageWriter.writeToStream(bitMatrix, format);
	}
}