/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.os;
import android.app.admin.DevicePolicyManager;
import android.content.Context;
import android.os.storage.IMountService;
import android.os.storage.StorageVolume;
import android.text.TextUtils;
import android.util.Log;
import com.google.android.collect.Lists;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
/**
* Provides access to environment variables.
*/
public class Environment {
private static final String TAG = "Environment";
private static final String ENV_EXTERNAL_STORAGE = "EXTERNAL_STORAGE";
private static final String ENV_EMULATED_STORAGE_SOURCE = "EMULATED_STORAGE_SOURCE";
private static final String ENV_EMULATED_STORAGE_TARGET = "EMULATED_STORAGE_TARGET";
private static final String ENV_MEDIA_STORAGE = "MEDIA_STORAGE";
private static final String ENV_SECONDARY_STORAGE = "SECONDARY_STORAGE";
private static final String ENV_ANDROID_ROOT = "ANDROID_ROOT";
private static final String ENV_OEM_ROOT = "OEM_ROOT";
private static final String ENV_VENDOR_ROOT = "VENDOR_ROOT";
/** {@hide} */
public static final String DIR_ANDROID = "Android";
private static final String DIR_DATA = "data";
private static final String DIR_MEDIA = "media";
private static final String DIR_OBB = "obb";
private static final String DIR_FILES = "files";
private static final String DIR_CACHE = "cache";
/** {@hide} */
@Deprecated
public static final String DIRECTORY_ANDROID = DIR_ANDROID;
private static final File DIR_ANDROID_ROOT = getDirectory(ENV_ANDROID_ROOT, "/system");
private static final File DIR_OEM_ROOT = getDirectory(ENV_OEM_ROOT, "/oem");
private static final File DIR_VENDOR_ROOT = getDirectory(ENV_VENDOR_ROOT, "/vendor");
private static final File DIR_MEDIA_STORAGE = getDirectory(ENV_MEDIA_STORAGE, "/data/media");
private static final String CANONCIAL_EMULATED_STORAGE_TARGET = getCanonicalPathOrNull(
ENV_EMULATED_STORAGE_TARGET);
private static final String SYSTEM_PROPERTY_EFS_ENABLED = "persist.security.efs.enabled";
private static UserEnvironment sCurrentUser;
private static boolean sUserRequired;
static {
initForCurrentUser();
}
/** {@hide} */
public static void initForCurrentUser() {
final int userId = UserHandle.myUserId();
sCurrentUser = new UserEnvironment(userId);
}
/** {@hide} */
public static class UserEnvironment {
// TODO: generalize further to create package-specific environment
/** External storage dirs, as visible to vold */
private final File[] mExternalDirsForVold;
/** External storage dirs, as visible to apps */
private final File[] mExternalDirsForApp;
/** Primary emulated storage dir for direct access */
private final File mEmulatedDirForDirect;
public UserEnvironment(int userId) {
// See storage config details at http://source.android.com/tech/storage/
String rawExternalStorage = System.getenv(ENV_EXTERNAL_STORAGE);
String rawEmulatedSource = System.getenv(ENV_EMULATED_STORAGE_SOURCE);
String rawEmulatedTarget = System.getenv(ENV_EMULATED_STORAGE_TARGET);
String rawMediaStorage = System.getenv(ENV_MEDIA_STORAGE);
if (TextUtils.isEmpty(rawMediaStorage)) {
rawMediaStorage = "/data/media";
}
ArrayList<File> externalForVold = Lists.newArrayList();
ArrayList<File> externalForApp = Lists.newArrayList();
if (!TextUtils.isEmpty(rawEmulatedTarget)) {
// Device has emulated storage; external storage paths should have
// userId burned into them.
final String rawUserId = Integer.toString(userId);
final File emulatedSourceBase = new File(rawEmulatedSource);
final File emulatedTargetBase = new File(rawEmulatedTarget);
final File mediaBase = new File(rawMediaStorage);
// /storage/emulated/0
externalForVold.add(buildPath(emulatedSourceBase, rawUserId));
externalForApp.add(buildPath(emulatedTargetBase, rawUserId));
// /data/media/0
mEmulatedDirForDirect = buildPath(mediaBase, rawUserId);
} else {
// Device has physical external storage; use plain paths.
if (TextUtils.isEmpty(rawExternalStorage)) {
Log.w(TAG, "EXTERNAL_STORAGE undefined; falling back to default");
rawExternalStorage = "/storage/sdcard0";
}
// /storage/sdcard0
externalForVold.add(new File(rawExternalStorage));
externalForApp.add(new File(rawExternalStorage));
// /data/media
mEmulatedDirForDirect = new File(rawMediaStorage);
}
// Splice in any secondary storage paths, but only for owner
final String rawSecondaryStorage = System.getenv(ENV_SECONDARY_STORAGE);
if (!TextUtils.isEmpty(rawSecondaryStorage) && userId == UserHandle.USER_OWNER) {
for (String secondaryPath : rawSecondaryStorage.split(":")) {
externalForVold.add(new File(secondaryPath));
externalForApp.add(new File(secondaryPath));
}
}
mExternalDirsForVold = externalForVold.toArray(new File[externalForVold.size()]);
mExternalDirsForApp = externalForApp.toArray(new File[externalForApp.size()]);
}
@Deprecated
public File getExternalStorageDirectory() {
return mExternalDirsForApp[0];
}
@Deprecated
public File getExternalStoragePublicDirectory(String type) {
return buildExternalStoragePublicDirs(type)[0];
}
public File[] getExternalDirsForVold() {
return mExternalDirsForVold;
}
public File[] getExternalDirsForApp() {
return mExternalDirsForApp;
}
public File getMediaDir() {
return mEmulatedDirForDirect;
}
public File[] buildExternalStoragePublicDirs(String type) {
return buildPaths(mExternalDirsForApp, type);
}
public File[] buildExternalStorageAndroidDataDirs() {
return buildPaths(mExternalDirsForApp, DIR_ANDROID, DIR_DATA);
}
public File[] buildExternalStorageAndroidObbDirs() {
return buildPaths(mExternalDirsForApp, DIR_ANDROID, DIR_OBB);
}
public File[] buildExternalStorageAppDataDirs(String packageName) {
return buildPaths(mExternalDirsForApp, DIR_ANDROID, DIR_DATA, packageName);
}
public File[] buildExternalStorageAppDataDirsForVold(String packageName) {
return buildPaths(mExternalDirsForVold, DIR_ANDROID, DIR_DATA, packageName);
}
public File[] buildExternalStorageAppMediaDirs(String packageName) {
return buildPaths(mExternalDirsForApp, DIR_ANDROID, DIR_MEDIA, packageName);
}
public File[] buildExternalStorageAppMediaDirsForVold(String packageName) {
return buildPaths(mExternalDirsForVold, DIR_ANDROID, DIR_MEDIA, packageName);
}
public File[] buildExternalStorageAppObbDirs(String packageName) {
return buildPaths(mExternalDirsForApp, DIR_ANDROID, DIR_OBB, packageName);
}
public File[] buildExternalStorageAppObbDirsForVold(String packageName) {
return buildPaths(mExternalDirsForVold, DIR_ANDROID, DIR_OBB, packageName);
}
public File[] buildExternalStorageAppFilesDirs(String packageName) {
return buildPaths(mExternalDirsForApp, DIR_ANDROID, DIR_DATA, packageName, DIR_FILES);
}
public File[] buildExternalStorageAppCacheDirs(String packageName) {
return buildPaths(mExternalDirsForApp, DIR_ANDROID, DIR_DATA, packageName, DIR_CACHE);
}
}
/**
* Return root of the "system" partition holding the core Android OS.
* Always present and mounted read-only.
*/
public static File getRootDirectory() {
return DIR_ANDROID_ROOT;
}
/**
* Return root directory of the "oem" partition holding OEM customizations,
* if any. If present, the partition is mounted read-only.
*
* @hide
*/
public static File getOemDirectory() {
return DIR_OEM_ROOT;
}
/**
* Return root directory of the "vendor" partition that holds vendor-provided
* software that should persist across simple reflashing of the "system" partition.
* @hide
*/
public static File getVendorDirectory() {
return DIR_VENDOR_ROOT;
}
/**
* Gets the system directory available for secure storage.
* If Encrypted File system is enabled, it returns an encrypted directory (/data/secure/system).
* Otherwise, it returns the unencrypted /data/system directory.
* @return File object representing the secure storage system directory.
* @hide
*/
public static File getSystemSecureDirectory() {
if (isEncryptedFilesystemEnabled()) {
return new File(SECURE_DATA_DIRECTORY, "system");
} else {
return new File(DATA_DIRECTORY, "system");
}
}
/**
* Gets the data directory for secure storage.
* If Encrypted File system is enabled, it returns an encrypted directory (/data/secure).
* Otherwise, it returns the unencrypted /data directory.
* @return File object representing the data directory for secure storage.
* @hide
*/
public static File getSecureDataDirectory() {
if (isEncryptedFilesystemEnabled()) {
return SECURE_DATA_DIRECTORY;
} else {
return DATA_DIRECTORY;
}
}
/**
* Return directory used for internal media storage, which is protected by
* {@link android.Manifest.permission#WRITE_MEDIA_STORAGE}.
*
* @hide
*/
public static File getMediaStorageDirectory() {
throwIfUserRequired();
return sCurrentUser.getMediaDir();
}
/**
* Return the system directory for a user. This is for use by system services to store
* files relating to the user. This directory will be automatically deleted when the user
* is removed.
*
* @hide
*/
public static File getUserSystemDirectory(int userId) {
return new File(new File(getSystemSecureDirectory(), "users"), Integer.toString(userId));
}
/**
* Returns the config directory for a user. This is for use by system services to store files
* relating to the user which should be readable by any app running as that user.
*
* @hide
*/
public static File getUserConfigDirectory(int userId) {
return new File(new File(new File(
getDataDirectory(), "misc"), "user"), Integer.toString(userId));
}
/**
* Returns whether the Encrypted File System feature is enabled on the device or not.
* @return <code>true</code> if Encrypted File System feature is enabled, <code>false</code>
* if disabled.
* @hide
*/
public static boolean isEncryptedFilesystemEnabled() {
return SystemProperties.getBoolean(SYSTEM_PROPERTY_EFS_ENABLED, false);
}
private static final File DATA_DIRECTORY
= getDirectory("ANDROID_DATA", "/data");
/**
* @hide
*/
private static final File SECURE_DATA_DIRECTORY
= getDirectory("ANDROID_SECURE_DATA", "/data/secure");
private static final File DOWNLOAD_CACHE_DIRECTORY = getDirectory("DOWNLOAD_CACHE", "/cache");
/**
* Return the user data directory.
*/
public static File getDataDirectory() {
return DATA_DIRECTORY;
}
/**
* Return the primary external storage directory. This directory may not
* currently be accessible if it has been mounted by the user on their
* computer, has been removed from the device, or some other problem has
* happened. You can determine its current state with
* {@link #getExternalStorageState()}.
* <p>
* <em>Note: don't be confused by the word "external" here. This directory
* can better be thought as media/shared storage. It is a filesystem that
* can hold a relatively large amount of data and that is shared across all
* applications (does not enforce permissions). Traditionally this is an SD
* card, but it may also be implemented as built-in storage in a device that
* is distinct from the protected internal storage and can be mounted as a
* filesystem on a computer.</em>
* <p>
* On devices with multiple users (as described by {@link UserManager}),
* each user has their own isolated external storage. Applications only have
* access to the external storage for the user they're running as.
* <p>
* In devices with multiple "external" storage directories, this directory
* represents the "primary" external storage that the user will interact
* with. Access to secondary storage is available through
* <p>
* Applications should not directly use this top-level directory, in order
* to avoid polluting the user's root namespace. Any files that are private
* to the application should be placed in a directory returned by
* {@link android.content.Context#getExternalFilesDir
* Context.getExternalFilesDir}, which the system will take care of deleting
* if the application is uninstalled. Other shared files should be placed in
* one of the directories returned by
* {@link #getExternalStoragePublicDirectory}.
* <p>
* Writing to this path requires the
* {@link android.Manifest.permission#WRITE_EXTERNAL_STORAGE} permission,
* and starting in read access requires the
* {@link android.Manifest.permission#READ_EXTERNAL_STORAGE} permission,
* which is automatically granted if you hold the write permission.
* <p>
* Starting in {@link android.os.Build.VERSION_CODES#KITKAT}, if your
* application only needs to store internal data, consider using
* {@link Context#getExternalFilesDir(String)} or
* {@link Context#getExternalCacheDir()}, which require no permissions to
* read or write.
* <p>
* This path may change between platform versions, so applications should
* only persist relative paths.
* <p>
* Here is an example of typical code to monitor the state of external
* storage:
* <p>
* {@sample
* development/samples/ApiDemos/src/com/example/android/apis/content/ExternalStorage.java
* monitor_storage}
*
* @see #getExternalStorageState()
* @see #isExternalStorageRemovable()
*/
public static File getExternalStorageDirectory() {
throwIfUserRequired();
return sCurrentUser.getExternalDirsForApp()[0];
}
/** {@hide} */
public static File getLegacyExternalStorageDirectory() {
return new File(System.getenv(ENV_EXTERNAL_STORAGE));
}
/** {@hide} */
public static File getLegacyExternalStorageObbDirectory() {
return buildPath(getLegacyExternalStorageDirectory(), DIR_ANDROID, DIR_OBB);
}
/** {@hide} */
public static File getEmulatedStorageSource(int userId) {
// /mnt/shell/emulated/0
return new File(System.getenv(ENV_EMULATED_STORAGE_SOURCE), String.valueOf(userId));
}
/** {@hide} */
public static File getEmulatedStorageObbSource() {
// /mnt/shell/emulated/obb
return new File(System.getenv(ENV_EMULATED_STORAGE_SOURCE), DIR_OBB);
}
/**
* Standard directory in which to place any audio files that should be
* in the regular list of music for the user.
* This may be combined with
* {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS},
* {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_MUSIC = "Music";
/**
* Standard directory in which to place any audio files that should be
* in the list of podcasts that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_NOTIFICATIONS},
* {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_PODCASTS = "Podcasts";
/**
* Standard directory in which to place any audio files that should be
* in the list of ringtones that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, and
* {@link #DIRECTORY_ALARMS} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_RINGTONES = "Ringtones";
/**
* Standard directory in which to place any audio files that should be
* in the list of alarms that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS},
* and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_ALARMS = "Alarms";
/**
* Standard directory in which to place any audio files that should be
* in the list of notifications that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_PODCASTS},
* {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_NOTIFICATIONS = "Notifications";
/**
* Standard directory in which to place pictures that are available to
* the user. Note that this is primarily a convention for the top-level
* public directory, as the media scanner will find and collect pictures
* in any directory.
*/
public static String DIRECTORY_PICTURES = "Pictures";
/**
* Standard directory in which to place movies that are available to
* the user. Note that this is primarily a convention for the top-level
* public directory, as the media scanner will find and collect movies
* in any directory.
*/
public static String DIRECTORY_MOVIES = "Movies";
/**
* Standard directory in which to place files that have been downloaded by
* the user. Note that this is primarily a convention for the top-level
* public directory, you are free to download files anywhere in your own
* private directories. Also note that though the constant here is
* named DIRECTORY_DOWNLOADS (plural), the actual file name is non-plural for
* backwards compatibility reasons.
*/
public static String DIRECTORY_DOWNLOADS = "Download";
/**
* The traditional location for pictures and videos when mounting the
* device as a camera. Note that this is primarily a convention for the
* top-level public directory, as this convention makes no sense elsewhere.
*/
public static String DIRECTORY_DCIM = "DCIM";
/**
* Standard directory in which to place documents that have been created by
* the user.
*/
public static String DIRECTORY_DOCUMENTS = "Documents";
/**
* Get a top-level public external storage directory for placing files of
* a particular type. This is where the user will typically place and
* manage their own files, so you should be careful about what you put here
* to ensure you don't erase their files or get in the way of their own
* organization.
*
* <p>On devices with multiple users (as described by {@link UserManager}),
* each user has their own isolated external storage. Applications only
* have access to the external storage for the user they're running as.</p>
*
* <p>Here is an example of typical code to manipulate a picture on
* the public external storage:</p>
*
* {@sample development/samples/ApiDemos/src/com/example/android/apis/content/ExternalStorage.java
* public_picture}
*
* @param type The type of storage directory to return. Should be one of
* {@link #DIRECTORY_MUSIC}, {@link #DIRECTORY_PODCASTS},
* {@link #DIRECTORY_RINGTONES}, {@link #DIRECTORY_ALARMS},
* {@link #DIRECTORY_NOTIFICATIONS}, {@link #DIRECTORY_PICTURES},
* {@link #DIRECTORY_MOVIES}, {@link #DIRECTORY_DOWNLOADS}, or
* {@link #DIRECTORY_DCIM}. May not be null.
*
* @return Returns the File path for the directory. Note that this
* directory may not yet exist, so you must make sure it exists before
* using it such as with {@link File#mkdirs File.mkdirs()}.
*/
public static File getExternalStoragePublicDirectory(String type) {
throwIfUserRequired();
return sCurrentUser.buildExternalStoragePublicDirs(type)[0];
}
/**
* Returns the path for android-specific data on the SD card.
* @hide
*/
public static File[] buildExternalStorageAndroidDataDirs() {
throwIfUserRequired();
return sCurrentUser.buildExternalStorageAndroidDataDirs();
}
/**
* Generates the raw path to an application's data
* @hide
*/
public static File[] buildExternalStorageAppDataDirs(String packageName) {
throwIfUserRequired();
return sCurrentUser.buildExternalStorageAppDataDirs(packageName);
}
/**
* Generates the raw path to an application's media
* @hide
*/
public static File[] buildExternalStorageAppMediaDirs(String packageName) {
throwIfUserRequired();
return sCurrentUser.buildExternalStorageAppMediaDirs(packageName);
}
/**
* Generates the raw path to an application's OBB files
* @hide
*/
public static File[] buildExternalStorageAppObbDirs(String packageName) {
throwIfUserRequired();
return sCurrentUser.buildExternalStorageAppObbDirs(packageName);
}
/**
* Generates the path to an application's files.
* @hide
*/
public static File[] buildExternalStorageAppFilesDirs(String packageName) {
throwIfUserRequired();
return sCurrentUser.buildExternalStorageAppFilesDirs(packageName);
}
/**
* Generates the path to an application's cache.
* @hide
*/
public static File[] buildExternalStorageAppCacheDirs(String packageName) {
throwIfUserRequired();
return sCurrentUser.buildExternalStorageAppCacheDirs(packageName);
}
/**
* Return the download/cache content directory.
*/
public static File getDownloadCacheDirectory() {
return DOWNLOAD_CACHE_DIRECTORY;
}
/**
* Unknown storage state, such as when a path isn't backed by known storage
* media.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_UNKNOWN = "unknown";
/**
* Storage state if the media is not present.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_REMOVED = "removed";
/**
* Storage state if the media is present but not mounted.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_UNMOUNTED = "unmounted";
/**
* Storage state if the media is present and being disk-checked.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_CHECKING = "checking";
/**
* Storage state if the media is present but is blank or is using an
* unsupported filesystem.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_NOFS = "nofs";
/**
* Storage state if the media is present and mounted at its mount point with
* read/write access.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_MOUNTED = "mounted";
/**
* Storage state if the media is present and mounted at its mount point with
* read-only access.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_MOUNTED_READ_ONLY = "mounted_ro";
/**
* Storage state if the media is present not mounted, and shared via USB
* mass storage.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_SHARED = "shared";
/**
* Storage state if the media was removed before it was unmounted.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_BAD_REMOVAL = "bad_removal";
/**
* Storage state if the media is present but cannot be mounted. Typically
* this happens if the file system on the media is corrupted.
*
* @see #getExternalStorageState(File)
*/
public static final String MEDIA_UNMOUNTABLE = "unmountable";
/**
* Returns the current state of the primary "external" storage device.
*
* @see #getExternalStorageDirectory()
* @return one of {@link #MEDIA_UNKNOWN}, {@link #MEDIA_REMOVED},
* {@link #MEDIA_UNMOUNTED}, {@link #MEDIA_CHECKING},
* {@link #MEDIA_NOFS}, {@link #MEDIA_MOUNTED},
* {@link #MEDIA_MOUNTED_READ_ONLY}, {@link #MEDIA_SHARED},
* {@link #MEDIA_BAD_REMOVAL}, or {@link #MEDIA_UNMOUNTABLE}.
*/
public static String getExternalStorageState() {
final File externalDir = sCurrentUser.getExternalDirsForApp()[0];
return getExternalStorageState(externalDir);
}
/**
* @deprecated use {@link #getExternalStorageState(File)}
*/
@Deprecated
public static String getStorageState(File path) {
return getExternalStorageState(path);
}
/**
* Returns the current state of the storage device that provides the given
* path.
*
* @return one of {@link #MEDIA_UNKNOWN}, {@link #MEDIA_REMOVED},
* {@link #MEDIA_UNMOUNTED}, {@link #MEDIA_CHECKING},
* {@link #MEDIA_NOFS}, {@link #MEDIA_MOUNTED},
* {@link #MEDIA_MOUNTED_READ_ONLY}, {@link #MEDIA_SHARED},
* {@link #MEDIA_BAD_REMOVAL}, or {@link #MEDIA_UNMOUNTABLE}.
*/
public static String getExternalStorageState(File path) {
final StorageVolume volume = getStorageVolume(path);
if (volume != null) {
final IMountService mountService = IMountService.Stub.asInterface(
ServiceManager.getService("mount"));
try {
return mountService.getVolumeState(volume.getPath());
} catch (RemoteException e) {
}
}
return Environment.MEDIA_UNKNOWN;
}
/**
* Returns whether the primary "external" storage device is removable.
*
* @return true if the storage device can be removed (such as an SD card),
* or false if the storage device is built in and cannot be
* physically removed.
*/
public static boolean isExternalStorageRemovable() {
if (isStorageDisabled()) return false;
final File externalDir = sCurrentUser.getExternalDirsForApp()[0];
return isExternalStorageRemovable(externalDir);
}
/**
* Returns whether the storage device that provides the given path is
* removable.
*
* @return true if the storage device can be removed (such as an SD card),
* or false if the storage device is built in and cannot be
* physically removed.
* @throws IllegalArgumentException if the path is not a valid storage
* device.
*/
public static boolean isExternalStorageRemovable(File path) {
final StorageVolume volume = getStorageVolume(path);
if (volume != null) {
return volume.isRemovable();
} else {
throw new IllegalArgumentException("Failed to find storage device at " + path);
}
}
/**
* Returns whether the primary "external" storage device is emulated. If
* true, data stored on this device will be stored on a portion of the
* internal storage system.
*
* @see DevicePolicyManager#setStorageEncryption(android.content.ComponentName,
* boolean)
*/
public static boolean isExternalStorageEmulated() {
if (isStorageDisabled()) return false;
final File externalDir = sCurrentUser.getExternalDirsForApp()[0];
return isExternalStorageEmulated(externalDir);
}
/**
* Returns whether the storage device that provides the given path is
* emulated. If true, data stored on this device will be stored on a portion
* of the internal storage system.
*
* @throws IllegalArgumentException if the path is not a valid storage
* device.
*/
public static boolean isExternalStorageEmulated(File path) {
final StorageVolume volume = getStorageVolume(path);
if (volume != null) {
return volume.isEmulated();
} else {
throw new IllegalArgumentException("Failed to find storage device at " + path);
}
}
static File getDirectory(String variableName, String defaultPath) {
String path = System.getenv(variableName);
return path == null ? new File(defaultPath) : new File(path);
}
private static String getCanonicalPathOrNull(String variableName) {
String path = System.getenv(variableName);
if (path == null) {
return null;
}
try {
return new File(path).getCanonicalPath();
} catch (IOException e) {
Log.w(TAG, "Unable to resolve canonical path for " + path);
return null;
}
}
/** {@hide} */
public static void setUserRequired(boolean userRequired) {
sUserRequired = userRequired;
}
private static void throwIfUserRequired() {
if (sUserRequired) {
Log.wtf(TAG, "Path requests must specify a user by using UserEnvironment",
new Throwable());
}
}
/**
* Append path segments to each given base path, returning result.
*
* @hide
*/
public static File[] buildPaths(File[] base, String... segments) {
File[] result = new File[base.length];
for (int i = 0; i < base.length; i++) {
result[i] = buildPath(base[i], segments);
}
return result;
}
/**
* Append path segments to given base path, returning result.
*
* @hide
*/
public static File buildPath(File base, String... segments) {
File cur = base;
for (String segment : segments) {
if (cur == null) {
cur = new File(segment);
} else {
cur = new File(cur, segment);
}
}
return cur;
}
private static boolean isStorageDisabled() {
return SystemProperties.getBoolean("config.disable_storage", false);
}
private static StorageVolume getStorageVolume(File path) {
try {
path = path.getCanonicalFile();
} catch (IOException e) {
return null;
}
try {
final IMountService mountService = IMountService.Stub.asInterface(
ServiceManager.getService("mount"));
final StorageVolume[] volumes = mountService.getVolumeList();
for (StorageVolume volume : volumes) {
if (FileUtils.contains(volume.getPathFile(), path)) {
return volume;
}
}
} catch (RemoteException e) {
}
return null;
}
/**
* If the given path exists on emulated external storage, return the
* translated backing path hosted on internal storage. This bypasses any
* emulation later, improving performance. This is <em>only</em> suitable
* for read-only access.
* <p>
* Returns original path if given path doesn't meet these criteria. Callers
* must hold {@link android.Manifest.permission#WRITE_MEDIA_STORAGE}
* permission.
*
* @hide
*/
public static File maybeTranslateEmulatedPathToInternal(File path) {
// Fast return if not emulated, or missing variables
if (!Environment.isExternalStorageEmulated()
|| CANONCIAL_EMULATED_STORAGE_TARGET == null) {
return path;
}
try {
final String rawPath = path.getCanonicalPath();
if (rawPath.startsWith(CANONCIAL_EMULATED_STORAGE_TARGET)) {
final File internalPath = new File(DIR_MEDIA_STORAGE,
rawPath.substring(CANONCIAL_EMULATED_STORAGE_TARGET.length()));
if (internalPath.exists()) {
return internalPath;
}
}
} catch (IOException e) {
Log.w(TAG, "Failed to resolve canonical path for " + path);
}
// Unable to translate to internal path; use original
return path;
}
}
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