java中的base64字符流与图片的相互转换

//base64字符串转化成图片
    public static boolean GenerateImage(String imgStr)
    {   //对字节数组字符串进行Base64解码并生成图片
        if (imgStr == null) //图像数据为空
            return false;
        BASE64Decoder decoder = new BASE64Decoder();
        try
        {
            //Base64解码
            byte[] b = decoder.decodeBuffer(imgStr);
            for(int i=0;i<b.length;++i)
            {
                if(b[i]<0)
                {//调整异常数据
                    b[i]+=256;
                }
            }
            //生成jpeg图片
            String imgFilePath = "F:\\tmyyzz.jpg";//新生成的图片
            OutputStream out = new FileOutputStream(imgFilePath);   
            out.write(b);
            out.flush();
            out.close();
            return true;
        }
        catch (Exception e)
        {
            return false;
        }
    }



//图片转化成base64字符串
    public static String GetImageStr()
    {//将图片文件转化为字节数组字符串，并对其进行Base64编码处理
        String imgFile = "D:\\tupian\\jt.jpg";//待处理的图片
        InputStream in = null;
        byte[] data = null;
        //读取图片字节数组
        try
        {
            in = new FileInputStream(imgFile);       
            data = new byte[in.available()];
            in.read(data);
            in.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        //对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        return encoder.encode(data);//返回Base64编码过的字节数组字符串
    }