Android - 如何将文件从谷歌驱动器下载到 android SDCARD? [英] Android - How to download the file from google drive to android SDCARD?

问题描述

我已经使用桌面在谷歌驱动器中上传了一个 apk 文件.

I have uploaded an apk file in google drive using the desktop.

现在，当我单击我的 android 活动中的按钮时，我需要将该 apk 文件下载到我的 android SDCARD 中.如何做到这一点.

Now I need to download that apk file to in to my android SDCARD when I click on a button in my android activity. How to achieve this.

推荐答案

首先，你必须使用 RESTful API，因为您必须在 DRIVE_FILE 范围内打开云端硬盘.GDAA 只有 FILE 范围，不会看到您的 Android 应用未创建的任何内容.

First, you have to use the RESTful API, since you have to open Drive in a DRIVE_FILE scope. The GDAA has only FILE scope and will not see anything your Android app did not create.

在 RESTful API 中，这是一个 3 步过程

In the RESTful API, it is a 3 step process

1. 使用 LIST 获取文件 URL(通过 'title 查询')
2. 使用 GET(实际上是 getContent())来检索文件内容
3. 获取二进制流并将其保存到您的 SD 卡中

1. use LIST to get the file URL (query by 'title')
2. use GET (actually getContent()) to retrieve the file content
3. get binary stream and save it to your SD card

在第 1 步和第 2 步中，使用页面底部的试试看"游乐场来正确形成您的查询和字段选择.第 3 步在其他地方有详细记录.这是一些可能有帮助的断章取义的代码

In both step 1 and 2, use the 'try it' playground at the bottom of the pages to form your query and field selection correctly. Step 3 is well documented elsewhere. Here's some out-of-context code that may help

com.google.api.client.googleapis.extensions
  .android.gms.auth.GoogleAccountCredential _crd  = 
  GoogleAccountCredential.usingOAuth2(this, Arrays.asList(DriveScopes.DRIVE_FILE));
com.google.api.services.drive.Drive _svc =
new Drive.Builder(AndroidHttp.newCompatibleTransport(), new GsonFactory(), _crd).build();

// step 1: get the file list of files
com.google.api.services.drive.model.FileList gooLst = 
 _svc.files().list().setQ( [YOUR_REQUEST_STRING])
    .setFields("items(title,downloadUrl)").execute();
// get the URL from your list matching the title with the requested one

// step 2: get the file contents 
InputStream is = _svc.getRequestFactory()
 .buildGetRequest(new GenericUrl([URL_FROM_LIST]))
 .execute().getContent();

// step 3: stream it to you file
strm2File(is, [YOUR_FILE_NAME]);

private void strm2File(InputStream inStrm, String flNm) {
  try {
    OutputStream outStrm = 
        new FileOutputStream(new java.io.File(_ctx.getExternalFilesDir(null), flNm));
    try {
      try {
        final byte[] buffer = new byte[1024];
        int read; 
        while (((read = inStrm.read(buffer)) != -1) && (!isCancelled()))
          outStrm.write(buffer, 0, read);
        outStrm.flush();
      } finally {outStrm.close();}
    } catch (Exception e) {}
    inStrm.close();
  } catch (Exception e) {}
}

上面代码中的第 1 步和第 2 步必须在非 UI 线程中(如 AsyncTask)，并且必须实现很多错误处理(UserRecoverableAuthIOException...)围绕它.

Steps 1 and 2 in the code above have to be in the non-UI thread (like AsyncTask) and there is a lot of error handling that has to be implemented (UserRecoverableAuthIOException...) around it.

这篇关于Android - 如何将文件从谷歌驱动器下载到 android SDCARD?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！