How to get Google Drive file ID - google-drive-api

Question

I've created a file to Drive root using Google Drive Android API. How can I get this file ID to share it using Google Client Library?
Getting DriveFileResult in ResultCallback<DriveFileResult> callback returns Null:
String fileId = result.getDriveFile().getDriveId().getResourceId();

Answer 1

The callback is to the file being created locally. The DriveId will only have a resourceId when the file is synced to the server. Until then getResourceId will return null.
https://developer.android.com/reference/com/google/android/gms/drive/DriveId.html#getResourceId()
Use CompletionEvents to be notified when syncing with the server has occurred. Then calling getResourceId() should deliver what you are expecting.

Answer 2

this code might help to identify the id for a file present in the google drive.
public static void main(String[] args) throws IOException {
// Build a new authorized API client service.
Drive service = getDriveService();
// Print the names and IDs for up to 10 files.
FileList result = service.files().list()
.setMaxResults(10)
.execute();
List<File> files = result.getItems();
if (files == null || files.size() == 0) {
System.out.println("No files found.");
} else {
System.out.println("Files:");
for (File file : files) {
System.out.printf("%s (%s)\n", file.getTitle(), file.getId());
}
}
}