package test;

 import java.awt.image.BufferedImage;

 import java.io.ByteArrayInputStream;

 import java.io.ByteArrayOutputStream;

 import java.io.File;

 import java.util.Hashtable;

 import javax.imageio.ImageIO;

 import com.google.zxing.BarcodeFormat;

 import com.google.zxing.EncodeHintType;

 import com.google.zxing.MultiFormatWriter;

 import com.google.zxing.client.j2se.MatrixToImageWriter;

 import com.google.zxing.common.BitMatrix;

 import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;

 public class Test {

     public static void main(String[] args) throws Exception {

         String text = "你好";

         int width = 100;

         int height = 100;

         String format = "png";

         Hashtable hints = new Hashtable();

         hints.put(EncodeHintType.CHARACTER_SET, "utf-8");

         BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);

         File outputFile = new File("new.png");

         MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);

         byte[] b = toByteArray(new File("new.png"));

         new Base64();

         String s = Base64.encode(b);

         // String s = new String(b, "utf-8");

         System.out.println(s);

         // new Base64();

         ByteArrayInputStream in = new ByteArrayInputStream(Base64.decode(s));

         BufferedImage image = ImageIO.read(in);

         File newFile = new File("new2.png");

         ImageIO.write(image, "png", newFile);

     }

     public static byte[] toByteArray(File imageFile) throws Exception {

         BufferedImage img = ImageIO.read(imageFile);

         ByteArrayOutputStream buf = new ByteArrayOutputStream((int) imageFile.length());

         try {

             ImageIO.write(img, "jpg", buf);

         } catch (Exception e) {

             e.printStackTrace();

             return null;

         }

         return buf.toByteArray();

     }

 }