java根据内容生成二维码图片

 package util;

 import java.awt.image.BufferedImage;  

 import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;

 import javax.imageio.ImageIO;

 import java.util.Hashtable;

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

 /**
  * 二维码的生成需要借助MatrixToImageWriter类，该类是由Google提供的，可以将该类直接拷贝到源码中使用
  */
 public 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 void writeToStream(BitMatrix matrix, String format,
             OutputStream stream) throws IOException {
         BufferedImage image = toBufferedImage(matrix);
         if (!ImageIO.write(image, format, stream)) {
             throw new IOException("Could not write an image of format " + format);
         }
     }

     public static void main(String[] args) throws Exception {
         String text = "http://www.baidu.com"; // 二维码内容
         int width = 300; // 二维码图片宽度
         int height = 300; // 二维码图片高度
         String format = "jpg";// 二维码的图片格式

         Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
         hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 内容所使用字符集编码

         BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
                 BarcodeFormat.QR_CODE, width, height, hints);
         // 生成二维码
         File outputFile = new File("d:" + File.separator + "new.jpg");
         MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);
     }
 }