There are three ways of getting data that was previously uploaded:
## Download File
You can download file to a local directory using `Amplify.Storage.downloadFile`.
You can use the [path_provider](https://pub.dev/packages/path_provider) package to create a local file in the user's documents directory where you can store the downloaded data.
```dart
import 'package:path_provider/path_provider.dart';
Future downloadToLocalFile(String key) async {
final documentsDir = await getApplicationDocumentsDirectory();
final filepath = documentsDir.path + '/example.txt';
try {
final result = await Amplify.Storage.downloadFile(
key: key,
localFile: AWSFile.fromPath(filepath),
onProgress: (progress) {
safePrint('Fraction completed: ${progress.fractionCompleted}');
},
).result;
safePrint('Downloaded file is located at: ${result.localFile.path}');
} on StorageException catch (e) {
safePrint(e.message);
}
}
```
On Web, the download process will be handled by the browser. You can provide the downloaded file name by specifying the `path` parameter of `AWSFile.fromPath`. E.g. this instructs the browser to download the file `download.txt`.
```dart
Future downloadToLocalFileOnWeb(String key) async {
try {
final result = await Amplify.Storage.downloadFile(
key: key,
localFile: AWSFile.fromPath('download.txt'),
).result;
safePrint('Downloaded file: ${result.downloadedItem.key}');
} on StorageException catch (e) {
safePrint(e.message);
}
}
```
## Download data
You can download a file to in-memory buffer with `Amplify.Storage.downloadData`:
```dart
Future downloadToMemory(String key) async {
try {
final result = await Amplify.Storage.downloadData(
key: key,
onProgress: (progress) {
safePrint('Fraction completed: ${progress.fractionCompleted}');
},
).result;
safePrint('Downloaded data: ${result.bytes}');
} on StorageException catch (e) {
safePrint(e.message);
}
}
```
## Generate a download URL
You can get a downloadable URL for the file in storage by its key and access level.
When creating a downloadable URL, you can choose to check if the file exists by setting `validateObjectExistence` to
`true` in `S3GetUrlPluginOptions`. If the file is inaccessible or does not exist, a `StorageException` is thrown.
This allows you to check if an object exists during generating the presigned URL, which you can then use to download
that object.
```dart
Future getDownloadUrl({
required String key,
required StorageAccessLevel accessLevel,
}) async {
try {
final result = await Amplify.Storage.getUrl(
key: key,
options: const StorageGetUrlOptions(
accessLevel: accessLevel,
pluginOptions: S3GetUrlPluginOptions(
validateObjectExistence: true,
expiresIn: Duration(days: 1),
),
),
).result;
return result.url.toString();
} on StorageException catch (e) {
safePrint('Could not get a downloadable URL: ${e.message}');
rethrow;
}
}
```