java读取base64编码字符串并转成图片

    在网络中传输的图片，通常都是使用base64格式文件传输，本次读取的是保存在本地文件中的base64字符串，现在将其解析为原始图片。

import java.io.*;
import sun.misc.BASE64Decoder;

public class DailyCode {
    public static void main(String[] args) {
        String str;
        try {
            BufferedReader in = new BufferedReader(new FileReader("file/qr_bs64.txt"));
            while ((str=in.readLine()) != null) {
                break;
            }
        }catch (IOException e){
            System.out.println(e);
            str = "";
        }
        System.out.println(str);
        //对内容进行base64解码
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            FileOutputStream write = new FileOutputStream(new File("file/qr.png"));
            byte[] decodeBytes = decoder.decodeBuffer(str);
            write.write(decodeBytes);
            write.close();
        }catch (IOException e) {
            e.printStackTrace();
        }
    }
}

qrbs64.txt的内容如下：

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