AndroidStudyMemo (Resource)＝DownloadManager

http://developer.android.com/reference/android/app/DownloadManager.html

The download manager is a system service that handles long-running HTTP
downloads. Clients may request that a URI be downloaded to a particular
destination file. The download manager will conduct the download in the
background, taking care of HTTP interactions and retrying downloads after
failures or across connectivity changes and system reboots. Instances of
this class should be obtained through getSystemService(String) by passing
DOWNLOAD_SERVICE. Apps that request downloads through this API should
register a broadcast receiver for ACTION_NOTIFICATION_CLICKED to
appropriately handle when the user clicks on a running download in a
notification or from the downloads UI.