android - 如何将来自服务器的 base64 json 文件保存在移动外部存储中？

Question

我在 json 响应中从服务器获取一个 base64 字符串。它可能包含图像、zip 文件、pdf、mp3 或视频。如果我要解码 base 64 字符串，则在 imageview 中显示图像，但我想要下载文件并在移动图库中打开它，如果是图片，如果是 pdf 文件，它将像那样在 pdf 阅读器中打开....如何实现？

"attach":[{"id":6,"name":"Ticket.pdf","thread_id":17,"size":"356660","type":"application\/pdf","poster":"ATTACHMENT","created_at":"2018-03-13 11:40:32","updated_at":"2018-03-13 11:40:32","file":"base64 encoded string","driver":"local","path":"\/home\/jamboree\/public_html\/sayarnew\/storage\/app\/private\/2018\/3\/13"}]

Answer 1

根据您端点的字段，检查它是否是图像/pdf。既然你说你可以显示它 imageview，你可能有位图。将此位图转换为文件并将其存储在您的内存中(因此图像下载完成)。看下面的代码将位图转换为文件并存储在内存中

private void downLoadImage(Bitmap bitmap) {

String path = Environment.getExternalStorageDirectory().toString();
File directory = new File(path + "/dir_images");    
directory.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "IM_"+ n +".jpg";
File file = new File (directory, fname);
if (file.exists ())
  file.delete (); 
try {
    FileOutputStream out = new FileOutputStream(file);
    bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
    out.flush();
    out.close();

} catch (Exception e) {
     e.printStackTrace();
}
}