Environment.java revision d49c455cc97d5fcdd8af497dc2ba85efdc719959
1/* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.os; 18 19import java.io.File; 20 21import android.os.storage.IMountService; 22 23/** 24 * Provides access to environment variables. 25 */ 26public class Environment { 27 28 private static final File ROOT_DIRECTORY 29 = getDirectory("ANDROID_ROOT", "/system"); 30 31 private static final String SYSTEM_PROPERTY_EFS_ENABLED = "persist.security.efs.enabled"; 32 33 private static IMountService mMntSvc = null; 34 35 /** 36 * Gets the Android root directory. 37 */ 38 public static File getRootDirectory() { 39 return ROOT_DIRECTORY; 40 } 41 42 /** 43 * Gets the system directory available for secure storage. 44 * If Encrypted File system is enabled, it returns an encrypted directory (/data/secure/system). 45 * Otherwise, it returns the unencrypted /data/system directory. 46 * @return File object representing the secure storage system directory. 47 * @hide 48 */ 49 public static File getSystemSecureDirectory() { 50 if (isEncryptedFilesystemEnabled()) { 51 return new File(SECURE_DATA_DIRECTORY, "system"); 52 } else { 53 return new File(DATA_DIRECTORY, "system"); 54 } 55 } 56 57 /** 58 * Gets the data directory for secure storage. 59 * If Encrypted File system is enabled, it returns an encrypted directory (/data/secure). 60 * Otherwise, it returns the unencrypted /data directory. 61 * @return File object representing the data directory for secure storage. 62 * @hide 63 */ 64 public static File getSecureDataDirectory() { 65 if (isEncryptedFilesystemEnabled()) { 66 return SECURE_DATA_DIRECTORY; 67 } else { 68 return DATA_DIRECTORY; 69 } 70 } 71 72 /** 73 * Returns whether the Encrypted File System feature is enabled on the device or not. 74 * @return <code>true</code> if Encrypted File System feature is enabled, <code>false</code> 75 * if disabled. 76 * @hide 77 */ 78 public static boolean isEncryptedFilesystemEnabled() { 79 return SystemProperties.getBoolean(SYSTEM_PROPERTY_EFS_ENABLED, false); 80 } 81 82 private static final File DATA_DIRECTORY 83 = getDirectory("ANDROID_DATA", "/data"); 84 85 /** 86 * @hide 87 */ 88 private static final File SECURE_DATA_DIRECTORY 89 = getDirectory("ANDROID_SECURE_DATA", "/data/secure"); 90 91 private static final File EXTERNAL_STORAGE_DIRECTORY 92 = getDirectory("EXTERNAL_STORAGE", "/sdcard"); 93 94 private static final File EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY 95 = new File (new File(getDirectory("EXTERNAL_STORAGE", "/sdcard"), 96 "Android"), "data"); 97 98 private static final File EXTERNAL_STORAGE_ANDROID_MEDIA_DIRECTORY 99 = new File (new File(getDirectory("EXTERNAL_STORAGE", "/sdcard"), 100 "Android"), "media"); 101 102 private static final File DOWNLOAD_CACHE_DIRECTORY 103 = getDirectory("DOWNLOAD_CACHE", "/cache"); 104 105 /** 106 * Gets the Android data directory. 107 */ 108 public static File getDataDirectory() { 109 return DATA_DIRECTORY; 110 } 111 112 /** 113 * Gets the Android external storage directory. This directory may not 114 * currently be accessible if it has been mounted by the user on their 115 * computer, has been removed from the device, or some other problem has 116 * happened. You can determine its current state with 117 * {@link #getExternalStorageState()}. 118 * 119 * <p>Applications should not directly use this top-level directory, in 120 * order to avoid polluting the user's root namespace. Any files that are 121 * private to the application should be placed in a directory returned 122 * by {@link android.content.Context#getExternalFilesDir 123 * Context.getExternalFilesDir}, which the system will take care of deleting 124 * if the application is uninstalled. Other shared files should be placed 125 * in one of the directories returned by 126 * {@link #getExternalStoragePublicDirectory}. 127 * 128 * <p>Here is an example of typical code to monitor the state of 129 * external storage:</p> 130 * 131 * {@sample development/samples/ApiDemos/src/com/example/android/apis/content/ExternalStorage.java 132 * monitor_storage} 133 */ 134 public static File getExternalStorageDirectory() { 135 return EXTERNAL_STORAGE_DIRECTORY; 136 } 137 138 /** 139 * Standard directory in which to place any audio files that should be 140 * in the regular list of music for the user. 141 * This may be combined with 142 * {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, 143 * {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series 144 * of directories to categories a particular audio file as more than one 145 * type. 146 */ 147 public static String DIRECTORY_MUSIC = "Music"; 148 149 /** 150 * Standard directory in which to place any audio files that should be 151 * in the list of podcasts that the user can select (not as regular 152 * music). 153 * This may be combined with {@link #DIRECTORY_MUSIC}, 154 * {@link #DIRECTORY_NOTIFICATIONS}, 155 * {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series 156 * of directories to categories a particular audio file as more than one 157 * type. 158 */ 159 public static String DIRECTORY_PODCASTS = "Podcasts"; 160 161 /** 162 * Standard directory in which to place any audio files that should be 163 * in the list of ringtones that the user can select (not as regular 164 * music). 165 * This may be combined with {@link #DIRECTORY_MUSIC}, 166 * {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, and 167 * {@link #DIRECTORY_ALARMS} as a series 168 * of directories to categories a particular audio file as more than one 169 * type. 170 */ 171 public static String DIRECTORY_RINGTONES = "Ringtones"; 172 173 /** 174 * Standard directory in which to place any audio files that should be 175 * in the list of alarms that the user can select (not as regular 176 * music). 177 * This may be combined with {@link #DIRECTORY_MUSIC}, 178 * {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, 179 * and {@link #DIRECTORY_RINGTONES} as a series 180 * of directories to categories a particular audio file as more than one 181 * type. 182 */ 183 public static String DIRECTORY_ALARMS = "Alarms"; 184 185 /** 186 * Standard directory in which to place any audio files that should be 187 * in the list of notifications that the user can select (not as regular 188 * music). 189 * This may be combined with {@link #DIRECTORY_MUSIC}, 190 * {@link #DIRECTORY_PODCASTS}, 191 * {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series 192 * of directories to categories a particular audio file as more than one 193 * type. 194 */ 195 public static String DIRECTORY_NOTIFICATIONS = "Notifications"; 196 197 /** 198 * Standard directory in which to place pictures that are available to 199 * the user. Note that this is primarily a convention for the top-level 200 * public directory, as the media scanner will find and collect pictures 201 * in any directory. 202 */ 203 public static String DIRECTORY_PICTURES = "Pictures"; 204 205 /** 206 * Standard directory in which to place movies that are available to 207 * the user. Note that this is primarily a convention for the top-level 208 * public directory, as the media scanner will find and collect movies 209 * in any directory. 210 */ 211 public static String DIRECTORY_MOVIES = "Movies"; 212 213 /** 214 * Standard directory in which to place files that have been downloaded by 215 * the user. Note that this is primarily a convention for the top-level 216 * public directory, you are free to download files anywhere in your own 217 * private directories. Also note that though the constant here is 218 * named DIRECTORY_DOWNLOADS (plural), the actual file name is non-plural for 219 * backwards compatibility reasons. 220 */ 221 public static String DIRECTORY_DOWNLOADS = "Download"; 222 223 /** 224 * The traditional location for pictures and videos when mounting the 225 * device as a camera. Note that this is primarily a convention for the 226 * top-level public directory, as this convention makes no sense elsewhere. 227 */ 228 public static String DIRECTORY_DCIM = "DCIM"; 229 230 /** 231 * Get a top-level public external storage directory for placing files of 232 * a particular type. This is where the user will typically place and 233 * manage their own files, so you should be careful about what you put here 234 * to ensure you don't erase their files or get in the way of their own 235 * organization. 236 * 237 * <p>Here is an example of typical code to manipulate a picture on 238 * the public external storage:</p> 239 * 240 * {@sample development/samples/ApiDemos/src/com/example/android/apis/content/ExternalStorage.java 241 * public_picture} 242 * 243 * @param type The type of storage directory to return. Should be one of 244 * {@link #DIRECTORY_MUSIC}, {@link #DIRECTORY_PODCASTS}, 245 * {@link #DIRECTORY_RINGTONES}, {@link #DIRECTORY_ALARMS}, 246 * {@link #DIRECTORY_NOTIFICATIONS}, {@link #DIRECTORY_PICTURES}, 247 * {@link #DIRECTORY_MOVIES}, {@link #DIRECTORY_DOWNLOADS}, or 248 * {@link #DIRECTORY_DCIM}. May not be null. 249 * 250 * @return Returns the File path for the directory. Note that this 251 * directory may not yet exist, so you must make sure it exists before 252 * using it such as with {@link File#mkdirs File.mkdirs()}. 253 */ 254 public static File getExternalStoragePublicDirectory(String type) { 255 return new File(getExternalStorageDirectory(), type); 256 } 257 258 /** 259 * Returns the path for android-specific data on the SD card. 260 * @hide 261 */ 262 public static File getExternalStorageAndroidDataDir() { 263 return EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY; 264 } 265 266 /** 267 * Generates the raw path to an application's data 268 * @hide 269 */ 270 public static File getExternalStorageAppDataDirectory(String packageName) { 271 return new File(EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY, packageName); 272 } 273 274 /** 275 * Generates the raw path to an application's media 276 * @hide 277 */ 278 public static File getExternalStorageAppMediaDirectory(String packageName) { 279 return new File(EXTERNAL_STORAGE_ANDROID_MEDIA_DIRECTORY, packageName); 280 } 281 282 /** 283 * Generates the path to an application's files. 284 * @hide 285 */ 286 public static File getExternalStorageAppFilesDirectory(String packageName) { 287 return new File(new File(EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY, 288 packageName), "files"); 289 } 290 291 /** 292 * Generates the path to an application's cache. 293 * @hide 294 */ 295 public static File getExternalStorageAppCacheDirectory(String packageName) { 296 return new File(new File(EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY, 297 packageName), "cache"); 298 } 299 300 /** 301 * Gets the Android Download/Cache content directory. 302 */ 303 public static File getDownloadCacheDirectory() { 304 return DOWNLOAD_CACHE_DIRECTORY; 305 } 306 307 /** 308 * getExternalStorageState() returns MEDIA_REMOVED if the media is not present. 309 */ 310 public static final String MEDIA_REMOVED = "removed"; 311 312 /** 313 * getExternalStorageState() returns MEDIA_UNMOUNTED if the media is present 314 * but not mounted. 315 */ 316 public static final String MEDIA_UNMOUNTED = "unmounted"; 317 318 /** 319 * getExternalStorageState() returns MEDIA_CHECKING if the media is present 320 * and being disk-checked 321 */ 322 public static final String MEDIA_CHECKING = "checking"; 323 324 /** 325 * getExternalStorageState() returns MEDIA_NOFS if the media is present 326 * but is blank or is using an unsupported filesystem 327 */ 328 public static final String MEDIA_NOFS = "nofs"; 329 330 /** 331 * getExternalStorageState() returns MEDIA_MOUNTED if the media is present 332 * and mounted at its mount point with read/write access. 333 */ 334 public static final String MEDIA_MOUNTED = "mounted"; 335 336 /** 337 * getExternalStorageState() returns MEDIA_MOUNTED_READ_ONLY if the media is present 338 * and mounted at its mount point with read only access. 339 */ 340 public static final String MEDIA_MOUNTED_READ_ONLY = "mounted_ro"; 341 342 /** 343 * getExternalStorageState() returns MEDIA_SHARED if the media is present 344 * not mounted, and shared via USB mass storage. 345 */ 346 public static final String MEDIA_SHARED = "shared"; 347 348 /** 349 * getExternalStorageState() returns MEDIA_BAD_REMOVAL if the media was 350 * removed before it was unmounted. 351 */ 352 public static final String MEDIA_BAD_REMOVAL = "bad_removal"; 353 354 /** 355 * getExternalStorageState() returns MEDIA_UNMOUNTABLE if the media is present 356 * but cannot be mounted. Typically this happens if the file system on the 357 * media is corrupted. 358 */ 359 public static final String MEDIA_UNMOUNTABLE = "unmountable"; 360 361 /** 362 * Gets the current state of the external storage device. 363 * Note: This call should be deprecated as it doesn't support 364 * multiple volumes. 365 * 366 * <p>See {@link #getExternalStorageDirectory()} for an example of its use. 367 */ 368 public static String getExternalStorageState() { 369 try { 370 if (mMntSvc == null) { 371 mMntSvc = IMountService.Stub.asInterface(ServiceManager 372 .getService("mount")); 373 } 374 return mMntSvc.getVolumeState(getExternalStorageDirectory().toString()); 375 } catch (Exception rex) { 376 return Environment.MEDIA_REMOVED; 377 } 378 } 379 380 static File getDirectory(String variableName, String defaultPath) { 381 String path = System.getenv(variableName); 382 return path == null ? new File(defaultPath) : new File(path); 383 } 384} 385