Java--二维码生成&图片和流转化

 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();
     }

 }