Android应用程序获取系统路径

内部存储

Environment.getDataDirectory():   // ---/data
Context.getCacheDir():            // ---/data/data/{packagename}/cache
Context.getFilesDir():            // ---/data/data/{packagename}/files
Context.getFileStreamPath(""):    // ---/data/data/{packagename}/files
Context.getFileStreamPath("test"): //---/data/data/{packagename}/files/test

内部存储

Environment.getExternalStorageDirectory():   //---/storage/emulated/0
Context.getExternalCacheDir():    //---/storage/emulated/0/Android/data/{packagename}/cache
Context.getExternalFilesDir(""):   //--- /storage/emulated/0/Android/data/{packagename}/files
Context.getExternalFilesDir("test"):  //---/storage/emulated/0/Android/data/{packagename}/files/test
Context.getExternalFilesDir(Environment.DIRECTORY_PICTURES):  //---/storage/emulated/0/Android/data/{packagename}/files/Pictures

公共存储

Environment.getExternalStorageDirectory(): //---/storage/emulated/0
Environment.getExternalStoragePublicDirectory("")://---/storage/emulated/0
Environment.getExternalStoragePublicDirectory("test")://---/storage/emulated/0/test
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)：//---/storage/emulated/0/Pictures

frameworks/base/core/java/android/os/Environment.java 部分定义

public static String DIRECTORY_MUSIC = "Music";
public static String DIRECTORY_ALARMS = "Alarms";
public static String DIRECTORY_NOTIFICATIONS = "Notifications";
public static String DIRECTORY_PICTURES = "Pictures";
public static String DIRECTORY_MOVIES = "Movies";
public static String DIRECTORY_DOWNLOADS = "Download";
public static String DIRECTORY_DCIM = "DCIM";
public static String DIRECTORY_DOCUMENTS = "Documents";