java生成二维码到文件，java生成二维码转成BASE64

如题，利用java和第三方库，把指定的字符串生成二维码，并且把二维码保存成图片，转换成BASE64格式。

需要的jar文件：

package com.xueyoucto.xueyou;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;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import sun.misc.BASE64Encoder;import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Hashtable;/*** Hello world!*/
public class App {public static void main(String[] args) throws IOException {System.out.println("hello world");String text = "999666111222";int width = 300;int height = 300;String format = "png";Hashtable hints = new Hashtable();hints.put(EncodeHintType.CHARACTER_SET, "utf-8");BitMatrix bitMatrix = null;try {bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);} catch (WriterException e) {e.printStackTrace();}//直接写入文件File outputFile = new File("d:/new.png");MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);//通过流写入文件，不需要flush()OutputStream os1 = new FileOutputStream("d:/new2.png");MatrixToImageWriter.writeToStream(bitMatrix, format, os1);BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix);ByteArrayOutputStream os = new ByteArrayOutputStream();//新建流。ImageIO.write(image, format, os);//利用ImageIO类提供的write方法，将bi以png图片的数据模式写入流。byte b[] = os.toByteArray();//从流中获取数据数组。String str = new BASE64Encoder().encode(b);System.out.println(str);}
}

运行结果：