Download files

Download to file

If you uploaded the data using the key ExampleKey, you can retrieve the data using Amplify.Storage.downloadFile.

1Amplify.Storage.downloadFile(
2        "ExampleKey",
3        new File(getApplicationContext().getFilesDir() + "/download.txt"),
4        result -> Log.i("MyAmplifyApp", "Successfully downloaded: " + result.getFile().getName()),
5        error -> Log.e("MyAmplifyApp",  "Download Failure", error)
6);

1val file = File("${applicationContext.filesDir}/download.txt")
2Amplify.Storage.downloadFile("ExampleKey", file,
3    { Log.i("MyAmplifyApp", "Successfully downloaded: ${it.file.name}") },
4    { Log.e("MyAmplifyApp",  "Download Failure", it) }
5)

1try {
2    val file = File("${applicationContext.filesDir}/download.txt")
3    val download = Amplify.Storage.downloadFile("ExampleKey", file)
4    try {
5        val fileName = download.result().file.name
6        Log.i("MyAmplifyApp", "Successfully downloaded: $fileName")
7    } catch (error: StorageException) {
8        Log.e("MyAmplifyApp", "Download Failure", error)
9    }
10}

1RxProgressAwareSingleOperation<StorageDownloadFileResult> download =
2        RxAmplify.Storage.downloadFile(
3            "ExampleKey",
4            new File(getApplicationContext().getFilesDir() + "/download.txt"
5        );
6
7download
8    .observeResult()
9    .subscribe(
10        result -> Log.i("MyAmplifyApp", "Successfully downloaded: " + result.getFile().getName()),
11        error -> Log.e("MyAmplifyApp",  "Download Failure", error)
12    );

Track download progress

To track progress of the download, use the downloadFile API that includes a progress listener callback.

1Amplify.Storage.downloadFile(
2        "ExampleKey",
3        new File(getApplicationContext().getFilesDir() + "/download.txt"),
4        StorageDownloadFileOptions.defaultInstance(),
5        progress -> Log.i("MyAmplifyApp", "Fraction completed: " + progress.getFractionCompleted()),
6        result -> Log.i("MyAmplifyApp", "Successfully downloaded: " + result.getFile().getName()),
7        error -> Log.e("MyAmplifyApp",  "Download Failure", error)
8);

1val file = File("${applicationContext.filesDir}/download.txt")
2val options = StorageDownloadFileOptions.defaultInstance()
3Amplify.Storage.downloadFile("ExampleKey", file, options,
4    { Log.i("MyAmplifyApp", "Fraction completed: ${it.fractionCompleted}") },
5    { Log.i("MyAmplifyApp", "Successfully downloaded: ${it.file.name}") },
6    { Log.e("MyAmplifyApp", "Download Failure", it) }
7)

1val file = File("${applicationContext.filesDir}/download.txt")
2val options = StorageDownloadFileOptions.defaultInstance()
3val download = Amplify.Storage.downloadFile("ExampleKey", file, options)
4val progressJob = activityScope.async {
5    download.progress().collect { progress ->
6        Log.i("MyAmplifyApp", "Fraction completed: ${progress.fractionCompleted}")
7    }
8}
9try {
10    val fileName = download.result().file.name
11    Log.i("MyAmplifyApp", "Successfully downloaded: $fileName")
12} catch (error: StorageException) {
13    Log.e("MyAmplifyApp", "Download Failure", error)
14}
15progressJob.cancel()

1RxProgressAwareSingleOperation<StorageDownloadFileResult> download =
2        RxAmplify.Storage.downloadFile(remoteKey, localFile);
3
4download
5    .observeProgress()
6    .subscribe(
7      progress -> Log.i("MyAmplifyApp", progress.getFractionCompleted())
8    );

Generate a download URL

You can also retrieve a URL for the object in storage:

1Amplify.Storage.getUrl(
2    "ExampleKey",
3    result -> Log.i("MyAmplifyApp", "Successfully generated: " + result.getUrl()),
4    error -> Log.e("MyAmplifyApp", "URL generation failure", error)
5);

1Amplify.Storage.getUrl(
2    "ExampleKey",
3    { Log.i("MyAmplifyApp", "Successfully generated: ${it.url}") },
4    { Log.e("MyAmplifyApp", "URL generation failure", it) }
5)

1try {
2    val url = Amplify.Storage.getUrl("ExampleKey").url
3    Log.i("MyAmplifyApp", "Successfully generated: $url")
4} catch (error: StorageException) {
5    Log.e("MyAmplifyApp", "URL generation failure", error)
6}

1RxAmplify.Storage.getUrl("ExampleKey").subscribe(
2    result -> Log.i("MyAmplifyApp", "Successfully generated: " + result.getUrl()),
3    error -> Log.e("MyAmplifyApp", "URL generation failure", error)
4);

Upload files

Query transfers