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();
    }

}