Android S3 SDK Download File sample code (Download file 到你的手機下載資料夾) （Android的一百種奇技淫巧）

沒用過AWS 下載，方式蠻多，研究了一陣子，記錄分享。

public class MainActivity extends AppCompatActivity {

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        String awsAccessKey = "Your-awsAccessKey";        String awsSecretKey = "Your-awsSecretKey";        String sessionToken = "Your-sessionToken";
        AWSSessionCredentials awsCred = new BasicSessionCredentials(awsAccessKey
                , awsSecretKey, sessionToken);
        String fileKey = "Your-fileKey";        downloadWithTransferUtility(fileKey, awsCred);    }

    private void downloadWithTransferUtility(String fileKey, AWSSessionCredentials awsCred) {
        TransferNetworkLossHandler.getInstance(getApplicationContext());        AmazonS3Client s3Client = new AmazonS3Client(awsCred, Region.getRegion(Regions.AP_NORTHEAST_1), new ClientConfiguration());
        TransferUtility transferUtility =
                TransferUtility.builder()
                        .context(getApplicationContext())
                        .awsConfiguration(AWSMobileClient.getInstance().getConfiguration())
                        .s3Client(s3Client)
                        .defaultBucket("Your-BucketName")
                        .build();
        String fileName = getDownloadFileName(fileKey);        TransferObserver downloadObserver =
                transferUtility.download(fileKey,                        new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + fileName));
        // Attach a listener to the observer to get state update and progress notifications        downloadObserver.setTransferListener(new TransferListener() {
            @Override            public void onStateChanged(int id, TransferState state) {
                if (TransferState.COMPLETED == state) {
                    // Handle a completed upload.                    Toast.makeText(MainActivity.this, "TransferState.COMPLETED", Toast.LENGTH_SHORT).show();                }
            }

            @Override            public void onProgressChanged(int id, long bytesCurrent, long bytesTotal) {
                float percentDonef = ((float) bytesCurrent / (float) bytesTotal) * 100;                int percentDone = (int) percentDonef;                Log.d("Your Activity", "   ID:" + id + "   bytesCurrent: " + bytesCurrent + "   bytesTotal: " + bytesTotal + " " + percentDone + "%");            }

            @Override            public void onError(int id, Exception ex) {
                // Handle errors            }
        });    }

    public String getDownloadFileName(String key) {
        String[] path_split = key.split("/");        return path_split[path_split.length - 1];    }
}