android 一些路径的标准写法

一些路径的标准写法

 Environment.getDataDirectory() = /data
 Environment.getDownloadCacheDirectory() = /cache
 Environment.getExternalStorageDirectory() = /mnt/sdcard
 Environment.getRootDirectory() = /system
 context.getCacheDir() = /data/data/com.mt.mtpp/cache
 context.getExternalCacheDir() = /mnt/sdcard/Android/data/com.mt.mtpp/cache
 context.getFilesDir() = /data/data/com.mt.mtpp/files