Environment.java revision e83cefcef07f9ac025642c1ffec76b4c7ab39cf2
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>Here is an example of typical code to monitor the state of 120 * external storage:</p> 121 * 122 * {@sample development/samples/ApiDemos/src/com/example/android/apis/content/ExternalStorage.java 123 * monitor_storage} 124 */ 125 public static File getExternalStorageDirectory() { 126 return EXTERNAL_STORAGE_DIRECTORY; 127 } 128 129 /** 130 * Standard directory in which to place any audio files that should be 131 * in the regular list of music for the user. 132 * This may be combined with 133 * {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, 134 * {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series 135 * of directories to categories a particular audio file as more than one 136 * type. 137 */ 138 public static String DIRECTORY_MUSIC = "Music"; 139 140 /** 141 * Standard directory in which to place any audio files that should be 142 * in the list of podcasts that the user can select (not as regular 143 * music). 144 * This may be combined with {@link #DIRECTORY_MUSIC}, 145 * {@link #DIRECTORY_NOTIFICATIONS}, 146 * {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series 147 * of directories to categories a particular audio file as more than one 148 * type. 149 */ 150 public static String DIRECTORY_PODCASTS = "Podcasts"; 151 152 /** 153 * Standard directory in which to place any audio files that should be 154 * in the list of ringtones that the user can select (not as regular 155 * music). 156 * This may be combined with {@link #DIRECTORY_MUSIC}, 157 * {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, and 158 * {@link #DIRECTORY_ALARMS} as a series 159 * of directories to categories a particular audio file as more than one 160 * type. 161 */ 162 public static String DIRECTORY_RINGTONES = "Ringtones"; 163 164 /** 165 * Standard directory in which to place any audio files that should be 166 * in the list of alarms that the user can select (not as regular 167 * music). 168 * This may be combined with {@link #DIRECTORY_MUSIC}, 169 * {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, 170 * and {@link #DIRECTORY_RINGTONES} as a series 171 * of directories to categories a particular audio file as more than one 172 * type. 173 */ 174 public static String DIRECTORY_ALARMS = "Alarms"; 175 176 /** 177 * Standard directory in which to place any audio files that should be 178 * in the list of notifications that the user can select (not as regular 179 * music). 180 * This may be combined with {@link #DIRECTORY_MUSIC}, 181 * {@link #DIRECTORY_PODCASTS}, 182 * {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series 183 * of directories to categories a particular audio file as more than one 184 * type. 185 */ 186 public static String DIRECTORY_NOTIFICATIONS = "Notifications"; 187 188 /** 189 * Standard directory in which to place pictures that are available to 190 * the user. Note that this is primarily a convention for the top-level 191 * public directory, as the media scanner will find and collect pictures 192 * in any directory. 193 */ 194 public static String DIRECTORY_PICTURES = "Pictures"; 195 196 /** 197 * Standard directory in which to place movies that are available to 198 * the user. Note that this is primarily a convention for the top-level 199 * public directory, as the media scanner will find and collect movies 200 * in any directory. 201 */ 202 public static String DIRECTORY_MOVIES = "Movies"; 203 204 /** 205 * Standard directory in which to place files that have been downloaded by 206 * the user. Note that this is primarily a convention for the top-level 207 * public directory, you are free to download files anywhere in your own 208 * private directories. 209 */ 210 public static String DIRECTORY_DOWNLOADS = "Downloads"; 211 212 /** 213 * The traditional location for pictures and videos when mounting the 214 * device as a camera. Note that this is primarily a convention for the 215 * top-level public directory, as this convention makes no sense elsewhere. 216 */ 217 public static String DIRECTORY_DCIM = "DCIM"; 218 219 /** 220 * Get a top-level public external storage directory for placing files of 221 * a particular type. This is where the user will typically place and 222 * manage their own files, so you should be careful about what you put here 223 * to ensure you don't erase their files or get in the way of their own 224 * organization. 225 * 226 * <p>Here is an example of typical code to manipulate a picture on 227 * the public external storage:</p> 228 * 229 * {@sample development/samples/ApiDemos/src/com/example/android/apis/content/ExternalStorage.java 230 * public_picture} 231 * 232 * @param type The type of storage directory to return. Should be one of 233 * {@link #DIRECTORY_MUSIC}, {@link #DIRECTORY_PODCASTS}, 234 * {@link #DIRECTORY_RINGTONES}, {@link #DIRECTORY_ALARMS}, 235 * {@link #DIRECTORY_NOTIFICATIONS}, {@link #DIRECTORY_PICTURES}, 236 * {@link #DIRECTORY_MOVIES}, {@link #DIRECTORY_DOWNLOADS}, or 237 * {@link #DIRECTORY_DCIM}. May not be null. 238 * 239 * @return Returns the File path for the directory. Note that this 240 * directory may not yet exist, so you must make sure it exists before 241 * using it such as with {@link File#mkdirs File.mkdirs()}. 242 */ 243 public static File getExternalStoragePublicDirectory(String type) { 244 return new File(getExternalStorageDirectory(), type); 245 } 246 247 /** 248 * Returns the path for android-specific data on the SD card. 249 * @hide 250 */ 251 public static File getExternalStorageAndroidDataDir() { 252 return EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY; 253 } 254 255 /** 256 * Generates the raw path to an application's data 257 * @hide 258 */ 259 public static File getExternalStorageAppDataDirectory(String packageName) { 260 return new File(EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY, packageName); 261 } 262 263 /** 264 * Generates the raw path to an application's media 265 * @hide 266 */ 267 public static File getExternalStorageAppMediaDirectory(String packageName) { 268 return new File(EXTERNAL_STORAGE_ANDROID_MEDIA_DIRECTORY, packageName); 269 } 270 271 /** 272 * Generates the path to an application's files. 273 * @hide 274 */ 275 public static File getExternalStorageAppFilesDirectory(String packageName) { 276 return new File(new File(EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY, 277 packageName), "files"); 278 } 279 280 /** 281 * Generates the path to an application's cache. 282 * @hide 283 */ 284 public static File getExternalStorageAppCacheDirectory(String packageName) { 285 return new File(new File(EXTERNAL_STORAGE_ANDROID_DATA_DIRECTORY, 286 packageName), "cache"); 287 } 288 289 /** 290 * Gets the Android Download/Cache content directory. 291 */ 292 public static File getDownloadCacheDirectory() { 293 return DOWNLOAD_CACHE_DIRECTORY; 294 } 295 296 /** 297 * getExternalStorageState() returns MEDIA_REMOVED if the media is not present. 298 */ 299 public static final String MEDIA_REMOVED = "removed"; 300 301 /** 302 * getExternalStorageState() returns MEDIA_UNMOUNTED if the media is present 303 * but not mounted. 304 */ 305 public static final String MEDIA_UNMOUNTED = "unmounted"; 306 307 /** 308 * getExternalStorageState() returns MEDIA_CHECKING if the media is present 309 * and being disk-checked 310 */ 311 public static final String MEDIA_CHECKING = "checking"; 312 313 /** 314 * getExternalStorageState() returns MEDIA_NOFS if the media is present 315 * but is blank or is using an unsupported filesystem 316 */ 317 public static final String MEDIA_NOFS = "nofs"; 318 319 /** 320 * getExternalStorageState() returns MEDIA_MOUNTED if the media is present 321 * and mounted at its mount point with read/write access. 322 */ 323 public static final String MEDIA_MOUNTED = "mounted"; 324 325 /** 326 * getExternalStorageState() returns MEDIA_MOUNTED_READ_ONLY if the media is present 327 * and mounted at its mount point with read only access. 328 */ 329 public static final String MEDIA_MOUNTED_READ_ONLY = "mounted_ro"; 330 331 /** 332 * getExternalStorageState() returns MEDIA_SHARED if the media is present 333 * not mounted, and shared via USB mass storage. 334 */ 335 public static final String MEDIA_SHARED = "shared"; 336 337 /** 338 * getExternalStorageState() returns MEDIA_BAD_REMOVAL if the media was 339 * removed before it was unmounted. 340 */ 341 public static final String MEDIA_BAD_REMOVAL = "bad_removal"; 342 343 /** 344 * getExternalStorageState() returns MEDIA_UNMOUNTABLE if the media is present 345 * but cannot be mounted. Typically this happens if the file system on the 346 * media is corrupted. 347 */ 348 public static final String MEDIA_UNMOUNTABLE = "unmountable"; 349 350 /** 351 * Gets the current state of the external storage device. 352 * Note: This call should be deprecated as it doesn't support 353 * multiple volumes. 354 * 355 * <p>See {@link #getExternalStorageDirectory()} for an example of its use. 356 */ 357 public static String getExternalStorageState() { 358 try { 359 if (mMntSvc == null) { 360 mMntSvc = IMountService.Stub.asInterface(ServiceManager 361 .getService("mount")); 362 } 363 return mMntSvc.getVolumeState(getExternalStorageDirectory().toString()); 364 } catch (Exception rex) { 365 return Environment.MEDIA_REMOVED; 366 } 367 } 368 369 static File getDirectory(String variableName, String defaultPath) { 370 String path = System.getenv(variableName); 371 return path == null ? new File(defaultPath) : new File(path); 372 } 373} 374