如何将文本/纯文本文件从Google云端硬盘复制到Android App本地文件

Question

I can download the file but I can't copy it's contents.

I'm using this code:

HttpResponse resp = gDrive.getRequestFactory().buildGetRequest(new GenericUrl(driveFile.getDownloadUrl())).execute();
InputStream in= resp.getContent();
FileOutputStream fos = openFileOutput(fileName, Context.MODE_PRIVATE);
while(in.available()>0) {
    fos.write(in.read());
}

But the in.available() returns always 0. And yes, the content is there. If I just use in.read(), the first character comes ok.

The files are really small, just a few bytes or even empty.

Thanks.

Answer 1

Do not use available() . It is explicitly noted in the documentation that available() will only tell you how many bytes definitely are available, but that it may return 0 if it feels like it.

You want to use read(byte[]) to read chunks of undefined size into a buffer until it returns -1, and the write the corresponding amount of bytes out using write(byte[], int, int) - something like this:

byte[] buf = new byte[1024];
while (true) {
    int bytes = in.read(buf);
    if (bytes < 0) break;
    fos.write(buf, 0, bytes);
}

The Guava library provides a function for that .