Android Cache Partition

來自：http://dlwt.csdn.net/fd.php?i=326037831086282&s=eeb1c29671889674de8258c0f1e29882

 

Android Cache Partition

 

What means “Backup”？

Android's backup service allows you to copy your persistent application
data to remote "cloud" storage, in order to provide a restore point for the application data and settings. If a user performs a factory reset or converts to a new Android-powered device, the system automatically restores your backup data when the application
is re-installed. This way, your users don't need to reproduce their previous data or application settings. This process is completely transparent to the user and does not affect the functionality or user experience in your application.

How “Backup” works?

Settings->privacy->Back up my data   We can enable “Backup” here.When backupping,BackupManager copy app’s own files to /cache/backup/app_nameWhen restoring,BackupManager copy files back from /cache/backup/app_nameSystem apps who use “backup”:   Settings, browser,inputmethod,
userdictionary,   Wallpapers, wifi service and backup native command---bmgrThe space “Backup” takes depends on size of app’s files.

What’sDownloadProvider？

Android內部提供了一個DownloadProvider，是一個非常完整的下載工具，提供了很好的外部介面可以被其他應用程式調用，來完成下載工作。同時也提供和很好的下載、通知、儲存等機制。
在Android的Browser等工具裡面都用到了這個DownloadProvider。但是很遺憾的是，這個DownloadProvider不對app開發人員開放，只作為內部使用。Market.apk 源碼沒有公開，推斷使用了DownloadProvider進行app的下載