android文件存储解析

安卓中提供了Context中的方法与Environment类来获取目录。

Context文件操作方法

    public File getFileStreamPath(String name)    public String[] fileList()    public File getFilesDir()    public File getNoBackupFilesDir()    public File getExternalFilesDir(String type)    public File[] getExternalFilesDirs(String type)    public File getObbDir()    public File[] getObbDirs()     public File getCacheDir()    public File getCodeCacheDir()    public File getExternalCacheDir()     public File[] getExternalCacheDirs()    public File[] getExternalMediaDirs()     public File getDir(String name, int mode)

用Log把它们都显示出来

Log.d("context", "context.getFileStreamPath-->" +     this.getFileStreamPath("test").toString());Log.d("context", "context.getDir-->" +     this.getDir("test", Context.MODE_PRIVATE).toString());Log.d("context", "context.getFilesDir-->" +     this.getFilesDir().toString());Log.d("context", "context.getNoBackupFilesDir" +     this.getNoBackupFilesDir().toString());Log.d("context", "context.getCacheDir-->" +     this.getCacheDir().toString());Log.d("context", "context.getCodeCacheDir" +     this.getCodeCacheDir().toString());Log.d("context", "context.getDatabasePath-->" +     this.getDatabasePath("test").toString());Log.d("context", "context.getObbDir-->" +     this.getObbDir().toString());File[] files1 = this.getObbDirs();for (File file : files1) {    Log.d("context", "context.getObbDirs-->" + file.toString());}File[] files2 = this.getExternalMediaDirs();for (File file : files2) {    Log.d("context", "context.getExternalMediaDirs" + file.toString());}Log.d("context", "context.getExternalCacheDir-->" + this.getExternalCacheDir().toString());File[] files3 = this.getExternalCacheDirs();for (File file : files3) {    Log.d("context", "context.getExternalCacheDirs-->" + file.toString());}Log.d("context", "context.getExternalFilesDir-->" + this.getExternalFilesDir(Environment.DIRECTORY_ALARMS).toString());File[] files4 = this.getExternalFilesDirs(Environment.DIRECTORY_ALARMS);for (File file : files4) {    Log.d("context", "context.getExternalFilesDirs-->" + file.toString());}

Log输出结果(不同版本的安卓系统，目录可能也不相同，详见/storage/sdcard/0， /sdcard， /mnt/sdcard ，/storage/emulated/legacy 的区别)

context.getFileStreamPath-->/data/data/cn.hufeifei.environmenttest/files/testcontext.getDir-->/data/data/cn.hufeifei.environmenttest/app_testcontext.getFilesDir-->/data/data/cn.hufeifei.environmenttest/filescontext.getNoBackupFilesDir/data/data/cn.hufeifei.environmenttest/no_backupcontext.getCacheDir-->/data/data/cn.hufeifei.environmenttest/cachecontext.getCodeCacheDir/data/data/cn.hufeifei.environmenttest/code_cachecontext.getDatabasePath-->/data/data/cn.hufeifei.environmenttest/databases/testcontext.getObbDir-->/storage/emulated/0/Android/obb/cn.hufeifei.environmenttestcontext.getObbDirs-->/storage/emulated/0/Android/obb/cn.hufeifei.environmenttestcontext.getExternalMediaDirs/storage/emulated/0/Android/media/cn.hufeifei.environmenttestcontext.getExternalCacheDir-->/storage/emulated/0/Android/data/cn.hufeifei.environmenttest/cachecontext.getExternalCacheDirs-->/storage/emulated/0/Android/data/cn.hufeifei.environmenttest/cachecontext.getExternalFilesDir-->/storage/emulated/0/Android/data/cn.hufeifei.environmenttest/files/Alarmscontext.getExternalFilesDirs-->/storage/emulated/0/Android/data/cn.hufeifei.environmenttest/files/Alarms

Environment工具类中提供了以下几个方法：

Environment.getDataDirectory();Environment.getRootDirectory();Environment.getDownloadCacheDirectory();Environment.getExternalStoragePublicDirectory(String type);Environment.getExternalStorageDirectory();Environment.getExternalStorageState();Environment.getExternalStorageState(File path)Environment.getStorageState();//已被getExternalStorageState取代

1.前三个方法

用Log输出来：

//IS标识内部存储Log.d("Environment-IS", Environment.getDataDirectory().toString());Log.d("Environment-IS", Environment.getDownloadCacheDirectory().toString());Log.d("Environment-IS", Environment.getRootDirectory().toString());

输出结果为：

D/Environment-IS: /dataD/Environment-IS: /cacheD/Environment-IS: /system

2.getExternalStoragePublicDirectory方法
getExternalStoragePublicDirectory方法用来获取安卓外部存储中系统应用经常用到的公共文件夹，
在Environment中定义了这些文件夹的名字：

Environment.DIRECTORY_MUSIC = "Music"Environment.DIRECTORY_PODCASTS = "Podcasts"Environment.DIRECTORY_RINGTONES = "Ringtones"Environment.DIRECTORY_ALARMS = "Alarms"Environment.DIRECTORY_NOTIFICATIONS = "Notifications"Environment.DIRECTORY_PICTURES = "Pictures"Environment.DIRECTORY_MOVIES = "Movies"Environment.DIRECTORY_DOWNLOADS = "Download"Environment.DIRECTORY_DCIM = "DCIM"Environment.DIRECTORY_DOCUMENTS = "Documents"

它们的目录一般在/storage/emulated/0/ (dir_name就是Environment中定义的这些字符串常量)
3.最后的三个方法

最后面三个方法是用来获取挂载点的状态(在Linux中把一些特殊目录称为所谓的挂载点，有点类似于Windows中的分区)：

Environment.MEDIA_REMOVED;//媒体存储已经移除了Environment.MEDIA_UNMOUNTED;//存储媒体没有挂载Environment.MEDIA_CHECKING;//正在检查存储媒体Environment.MEDIA_NOFS;//存储媒体是空白或是不支持的文件系统no_file_systemEnvironment.MEDIA_MOUNTED;//存储媒体已经挂载，并且挂载点可读/写Environment.MEDIA_MOUNTED_READ_ONLY;//存储媒体已经挂载，挂载点只读Environment.MEDIA_SHARED;//存储媒体正在通过USB共享Environment.MEDIA_BAD_REMOVAL;//在没有挂载前存储媒体已经被移除Environment.MEDIA_UNMOUNTABLE;//存储媒体无法挂载,可能是文件系统损坏了Environment.MEDIA_EJECTING;//存储媒体正在移除Environment.MEDIA_UNKNOWN;//未知的存储状态

下面图片大概地概括了上面的方法

Context中的方法或得到的路径都与应用包名相关
Environment中的方法与整个系统有关

Android文件存储

android文件存储解析

Context文件操作方法

Environment工具类中提供了以下几个方法：

下面图片大概地概括了上面的方法

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