来自: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_name
When
restoring,BackupManager
copy files back from /cache/backup/
app_name
System apps who use “backup”:
Settings, browser,
inputmethod
,
userdictionary
,
Wallpapers,
wifi
service and backup native command---
bmgr
The space “Backup” takes depends on size of app’s files.
What’sDownloadProvider?
Android
内部提供了一个
DownloadProvider
,是一个非常完整的下载工具,提供了很好的外部接口可以被其他应用程序调用,来完成下载工作。同时也提供和很好的下载、通知、存储等机制。
在
Android
的
Browser
等工具里面都用到了这个
DownloadProvider
。
但是很遗憾的是,这个
DownloadProvider
不对
app
开发人员开放,只作为内部使用。
Market.apk
源码没有公开,推断使用了
DownloadProvider
进行
app
的下载