Android 存儲空間和存儲路徑總結

关于Android内部的存储空间，记忆很暧昧，每次都是现用现查。

今天又遇到了，借此机会系统的总结一下。

 

Â	路径取得方法	APP 专用	非root 用户可见	删除方法	APP 卸载时
å† éƒ¨æ•°æ®ç©ºé—´	Context.getFilesDir()	yes	no	主动删除	消失
å† éƒ¨ç¼“å­˜ç©ºé—´	Context.getCacheDir()	yes	no	æ¸ ç©ºç¼“å­˜	消失
外部数据空间	Context.getExternalFilesDir()	yes	yes	主动删除	消失
外部缓存空间	Context.getExternalCacheDir()	yes	yes	æ¸ ç©ºç¼“å­˜	消失
å¤–éƒ¨å ¬é–‹ç©ºé—´ (通常是/sdcard)	Environment.getExternalStorageDirectory()	no	yes	无法删除	不消失
å¤–éƒ¨å ¬é–‹å ±äº«ç©ºé—´	Environment.getExternalStoragePublicDirectory()	no	yes	无法删除	不消失

缓存空间没有大小限制。

内部空间只有APP自己可以访问，其他APP和手机用户都不可以见。卸载消失。

外部空间 APP自己，手机用户，其他授权APP可以访问。卸载消失

公開空间，所有APP都可以访问。卸载不消失。

 

 

以下作为补充阅读，看了会晕。

External 的字眼非常容易让人误会。根据字面联想，容易让人是手机外置空间(SD卡，外置硬盘之类)。

其实是指系统storage以外的storage的意思。

用getExternalXXXX()方法取得的空间有可能是 SD卡空间，也有可能还是手机内置存储空间。APP这边是无法控制的。

getExternalStorageDirectory取到的一般是/sdcard空间，但是不是绝对的，编程的时候需要注意。

如下面所示，根据手机不同，实际取到的路径也是不一样的。所以不要用绝对路径，要通过Context或者Enviroment来取。

206SH（Android4.2.2）

# 各种路径
Context.getFilesDir()                           :/data/data/com.example/files
Context.getCacheDir()                           :/data/data/com.example/cache
Context.getExternalCacheDir()                   :/storage/sdcard0/Android/data/com.example/cache
Context.getExternalFilesDir()                   :/storage/sdcard0/Android/data/com.example/files
Environment.getExternalStorageDirectory()       :/storage/sdcard0
Environment.getExternalStoragePublicDirectory() :/storage/sdcard0/DCIM
Environment.isExternalStorageEmulated()         :false
Environment.isExternalStorageRemovable()        :false

# 看看 getFilesDir() mount到哪里
/dev/block/platform/msm_sdcc.1/by-name/userdata /data ext4 rw,nosuid,nodev,noatime,discard,noauto_da_alloc,data=ordered 0 0
# 看看 getExternalStorageDirectory() 实际mount到哪里
/dev/fuse /storage/sdcard0 fuse rw,nosuid,nodev,relatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0
# 看看实际的SD卡mount到哪里
/dev/block/vold/179:33 /storage/sdcard0/external_sd vfat rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1015,fmask=0602,dmask=0602,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0
           

Nexus7（Android4.4.2）

# 各种路径
Context.getFilesDir()                           :/data/data/com.example/files
Context.getCacheDir()                           :/data/data/com.example/cache
Context.getExternalCacheDir()                   :/storage/emulated/0/Android/data/com.example/cache
Context.getExternalFilesDir()                   :/storage/emulated/0/Android/data/com.example/files
Environment.getExternalStorageDirectory()       :/storage/emulated/0
Environment.getExternalStoragePublicDirectory() :/storage/emulated/0/DCIM
Environment.isExternalStorageEmulated()         :true
Environment.isExternalStorageRemovable()        :false

# 看看 getFilesDir() 实际mount到哪里
/dev/block/platform/msm_sdcc.1/by-name/userdata /data ext4 rw,seclabel,nosuid,nodev,noatime,nomblk_io_submit,errors=panic,data=ordered 0 0
# 看看 getExternalStorageDirectory() 实际mount到哪里
/dev/fuse /mnt/shell/emulated fuse rw,nosuid,nodev,relatime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0

# /storage/emulated 是symlink,看看它的实际指向
[email protected]:/ $ ls -la /storage/emulated/
lrwxrwxrwx root     root              2014-01-30 19:47 legacy -> /mnt/shell/emulated/0
           

 

实验数据

Environment.getExternalStorageDirectory().toString();

/storage/emulated/0

但是实际指向的是 /sdcard/

adb pull /sdcard/test.jpg             即可把/storage/emulated/0下的数据拿出来

adb pull /storage/emulated/0/test.jpg 也能取出来

adb pull /mnt/sdcard/test4.jpg

各种API所取得的路径：

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)

      /storage/emulated/0/Pictures/

     /storage/emulated/0/Pictures/20200307

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);

    /storage/emulated/0/DCIM

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS);

    /storage/emulated/0/Documents

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);

    /storage/emulated/0/Download

Environment.getExternalStorageDirectory()得到的结果

 result = {[email protected]} "/storage/emulated/0"

      0 = {[email protected]} "/storage/emulated/0/Android"

      1 = {[email protected]} "/storage/emulated/0/Music"

      2 = {[email protected]} "/storage/emulated/0/Podcasts"

      3 = {[email protected]} "/storage/emulated/0/Ringtones"

      4 = {[email protected]} "/storage/emulated/0/Alarms"

      5 = {[email protected]} "/storage/emulated/0/Notifications"

      6 = {[email protected]} "/storage/emulated/0/Pictures"

      7 = {[email protected]} "/storage/emulated/0/Movies"

      8 = {[email protected]} "/storage/emulated/0/Download"

      9 = {[email protected]} "/storage/emulated/0/DCIM"

     10 = {[email protected]} "/storage/emulated/0/postasbuttonlogo.png"

     11 = {[email protected]} "/storage/emulated/0/logo_mark.png"

     12 = {[email protected]} "/storage/emulated/0/logo_mark_white.png"

     13 = {[email protected]} "/storage/emulated/0/logo_x_s.png"

     14 = {[email protected]} "/storage/emulated/0/test.jpg"

     15 = {[email protected]} "/storage/emulated/0/test2.jpg"

     16 = {[email protected]} "/storage/emulated/0/test3.jpg"

     17 = {[email protected]} "/storage/emulated/0/test4.jpg"

     18 = {[email protected]} "/storage/emulated/0/test5.jpg"

Environment.getRootDirectory()得到的结果

   result = {[email protected]} "/system"

        0 = {[email protected]} "/system/lost+found"

        1 = {[email protected]} "/system/app"

        2 = {[email protected]} "/system/bin"

        3 = {[email protected]} "/system/build.prop"

        4 = {[email protected]} "/system/compatibility_matrix.xml"

        5 = {[email protected]} "/system/etc"

        6 = {[email protected]} "/system/fake-libs"

        7 = {[email protected]} "/system/fonts"

        8 = {[email protected]} "/system/framework"

        9 = {[email protected]} "/system/lib"

       10 = {[email protected]} "/system/manifest.xml"

       11 = {[email protected]} "/system/media"

       12 = {[email protected]} "/system/priv-app"

       13 = {[email protected]} "/system/tts"

       14 = {[email protected]} "/system/usr"

       15 = {[email protected]} "/system/vendor"

       16 = {[email protected]} "/system/xbin"

Environment.getDataDirectory()

    /data

Environment.getDownloadCacheDirectory()

    /data/cache

context.cacheDir

result = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/cache"

 0 = {File@9209} "/data/user/0/jp.co.persol.postas.aposfood/cache/WebView"

 1 = {Fil[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/cache/volley"

 2 = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/cache/internalCache.txt"

context.externalCacheDir

        /storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/cache

context.externalCacheDirs

        /storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/cache

         0 = {[email protected]} "/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/cache"

         0 = {[email protected]} "/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/cache/test4.jpg"

两个互相看不到对方

context.externalMediaDirs

/storage/emulated/0/Android/media/jp.co.persol.postas.aposfood

context.fileList()

result = {String[4]@8894} 

 0 = "logs"

 1 = "download"

 2 = "work"

 3 = ".realm.temp"

context.filesDir

result = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/files"

 0 = {F[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/files/logs"

 1 = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/files/download"

 2 = {F[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/files/work"

 3 = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/files/.realm.temp"

context.dataDir

result = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood"

 0 = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/cache"

 1 = {F[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/code_cache"

 2 = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/lib"

 3 = {[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/files"

 4 = {Fi[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/app_webview"

 5 = {Fil[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/app_textures"

 6 = {Fil[email protected]} "/data/user/0/jp.co.persol.postas.aposfood/shared_prefs"

context.getExternalFilesDir(Environment.DIRECTORY_DCIM)

/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/files/DCIM

context.getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS)

/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/files/Documents

context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)

/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/files/Download

context.getExternalFilesDir(Environment.DIRECTORY_PICTURES)

/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/files/Pictures

context.getExternalFilesDir(Environment.DIRECTORY_NOTIFICATIONS)

/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/files/Notifications

context.getExternalFilesDir(Environment.MEDIA_MOUNTED)

/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/files/mounted

context.getExternalFilesDir(Environment.MEDIA_UNMOUNTED)

/storage/emulated/0/Android/data/jp.co.persol.postas.aposfood/files/unmounted