BluetoothAdapter.java revision 55e66f1b739097095f6b3c47f88de258898fc1c9
1/* 2 * Copyright (C) 2009 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.bluetooth; 18 19import android.annotation.SdkConstant; 20import android.annotation.SdkConstant.SdkConstantType; 21import android.os.RemoteException; 22import android.util.Log; 23 24import java.io.IOException; 25import java.util.Collections; 26import java.util.Set; 27import java.util.HashSet; 28 29/** 30 * Represents the local Bluetooth adapter. 31 * 32 * <p>Use {@link android.content.Context#getSystemService} with {@link 33 * android.content.Context#BLUETOOTH_SERVICE} to get the default local 34 * Bluetooth adapter. On most Android devices there is only one local 35 * Bluetotoh adapter. 36 * 37 * <p>Use the {@link BluetoothDevice} class for operations on remote Bluetooth 38 * devices. 39 */ 40public final class BluetoothAdapter { 41 private static final String TAG = "BluetoothAdapter"; 42 43 /** 44 * Sentinel error value for this class. Guaranteed to not equal any other 45 * integer constant in this class. Provided as a convenience for functions 46 * that require a sentinel error value, for example: 47 * <p><code>Intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 48 * BluetoothAdapter.ERROR)</code> 49 */ 50 public static final int ERROR = Integer.MIN_VALUE; 51 52 /** 53 * Broadcast Action: The state of the local Bluetooth adapter has been 54 * changed. 55 * <p>For example, Bluetooth has been turned on or off. 56 * <p>Always contains the extra fields {@link #EXTRA_STATE} and {@link 57 * #EXTRA_PREVIOUS_STATE} containing the new and old states 58 * respectively. 59 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 60 */ 61 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 62 public static final String ACTION_STATE_CHANGED = 63 "android.bluetooth.adapter.action.STATE_CHANGED"; 64 65 /** 66 * Used as an int extra field in {@link #ACTION_STATE_CHANGED} 67 * intents to request the current power state. Possible values are: 68 * {@link #STATE_OFF}, 69 * {@link #STATE_TURNING_ON}, 70 * {@link #STATE_ON}, 71 * {@link #STATE_TURNING_OFF}, 72 */ 73 public static final String EXTRA_STATE = 74 "android.bluetooth.adapter.extra.STATE"; 75 /** 76 * Used as an int extra field in {@link #ACTION_STATE_CHANGED} 77 * intents to request the previous power state. Possible values are: 78 * {@link #STATE_OFF}, 79 * {@link #STATE_TURNING_ON}, 80 * {@link #STATE_ON}, 81 * {@link #STATE_TURNING_OFF}, 82 */ 83 public static final String EXTRA_PREVIOUS_STATE = 84 "android.bluetooth.adapter.extra.PREVIOUS_STATE"; 85 86 /** 87 * Indicates the local Bluetooth adapter is off. 88 */ 89 public static final int STATE_OFF = 10; 90 /** 91 * Indicates the local Bluetooth adapter is turning on. However local 92 * clients should wait for {@link #STATE_ON} before attempting to 93 * use the adapter. 94 */ 95 public static final int STATE_TURNING_ON = 11; 96 /** 97 * Indicates the local Bluetooth adapter is on, and ready for use. 98 */ 99 public static final int STATE_ON = 12; 100 /** 101 * Indicates the local Bluetooth adapter is turning off. Local clients 102 * should immediately attempt graceful disconnection of any remote links. 103 */ 104 public static final int STATE_TURNING_OFF = 13; 105 106 /** 107 * Broadcast Action: Indicates the Bluetooth scan mode of the local Adapter 108 * has changed. 109 * <p>Always contains the extra fields {@link #EXTRA_SCAN_MODE} and {@link 110 * #EXTRA_PREVIOUS_SCAN_MODE} containing the new and old scan modes 111 * respectively. 112 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 113 */ 114 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 115 public static final String ACTION_SCAN_MODE_CHANGED = 116 "android.bluetooth.adapter.action.SCAN_MODE_CHANGED"; 117 118 /** 119 * Used as an int extra field in {@link #ACTION_SCAN_MODE_CHANGED} 120 * intents to request the current scan mode. Possible values are: 121 * {@link #SCAN_MODE_NONE}, 122 * {@link #SCAN_MODE_CONNECTABLE}, 123 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}, 124 */ 125 public static final String EXTRA_SCAN_MODE = "android.bluetooth.adapter.extra.SCAN_MODE"; 126 /** 127 * Used as an int extra field in {@link #ACTION_SCAN_MODE_CHANGED} 128 * intents to request the previous scan mode. Possible values are: 129 * {@link #SCAN_MODE_NONE}, 130 * {@link #SCAN_MODE_CONNECTABLE}, 131 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}, 132 */ 133 public static final String EXTRA_PREVIOUS_SCAN_MODE = 134 "android.bluetooth.adapter.extra.PREVIOUS_SCAN_MODE"; 135 136 /** 137 * Indicates that both inquiry scan and page scan are disabled on the local 138 * Bluetooth adapter. Therefore this device is neither discoverable 139 * nor connectable from remote Bluetooth devices. 140 */ 141 public static final int SCAN_MODE_NONE = 20; 142 /** 143 * Indicates that inquiry scan is disabled, but page scan is enabled on the 144 * local Bluetooth adapter. Therefore this device is not discoverable from 145 * remote Bluetooth devices, but is connectable from remote devices that 146 * have previously discovered this device. 147 */ 148 public static final int SCAN_MODE_CONNECTABLE = 21; 149 /** 150 * Indicates that both inquiry scan and page scan are enabled on the local 151 * Bluetooth adapter. Therefore this device is both discoverable and 152 * connectable from remote Bluetooth devices. 153 */ 154 public static final int SCAN_MODE_CONNECTABLE_DISCOVERABLE = 23; 155 156 157 /** 158 * Broadcast Action: The local Bluetooth adapter has started the remote 159 * device discovery process. 160 * <p>This usually involves an inquiry scan of about 12 seconds, followed 161 * by a page scan of each new device to retrieve its Bluetooth name. 162 * <p>Register for {@link BluetoothDevice#ACTION_FOUND} to be notified as 163 * remote Bluetooth devices are found. 164 * <p>Device discovery is a heavyweight procedure. New connections to 165 * remote Bluetooth devices should not be attempted while discovery is in 166 * progress, and existing connections will experience limited bandwidth 167 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 168 * discovery. 169 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 170 */ 171 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 172 public static final String ACTION_DISCOVERY_STARTED = 173 "android.bluetooth.adapter.action.DISCOVERY_STARTED"; 174 /** 175 * Broadcast Action: The local Bluetooth adapter has finished the device 176 * discovery process. 177 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 178 */ 179 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 180 public static final String ACTION_DISCOVERY_FINISHED = 181 "android.bluetooth.adapter.action.DISCOVERY_FINISHED"; 182 183 /** 184 * Broadcast Action: The local Bluetooth adapter has changed its friendly 185 * Bluetooth name. 186 * <p>This name is visible to remote Bluetooth devices. 187 * <p>Always contains the extra field {@link #EXTRA_LOCAL_NAME} containing 188 * the name. 189 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 190 */ 191 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 192 public static final String ACTION_LOCAL_NAME_CHANGED = 193 "android.bluetooth.adapter.action.LOCAL_NAME_CHANGED"; 194 /** 195 * Used as a String extra field in {@link #ACTION_LOCAL_NAME_CHANGED} 196 * intents to request the local Bluetooth name. 197 */ 198 public static final String EXTRA_LOCAL_NAME = "android.bluetooth.adapter.extra.LOCAL_NAME"; 199 200 private static final int ADDRESS_LENGTH = 17; 201 202 private final IBluetooth mService; 203 204 /** 205 * Do not use this constructor. Use Context.getSystemService() instead. 206 * @hide 207 */ 208 public BluetoothAdapter(IBluetooth service) { 209 if (service == null) { 210 throw new IllegalArgumentException("service is null"); 211 } 212 mService = service; 213 } 214 215 /** 216 * Get a {@link BluetoothDevice} object for the given Bluetooth hardware 217 * address. 218 * <p>Valid Bluetooth hardware addresses must be upper case, in a format 219 * such as "00:11:22:33:AA:BB". The helper {@link #checkBluetoothAddress} is 220 * available to validate a Bluetooth address. 221 * <p>A {@link BluetoothDevice} will always be returned for a valid 222 * hardware address, even if this adapter has never seen that device. 223 * 224 * @param address valid Bluetooth MAC address 225 * @throws IllegalArgumentException if address is invalid 226 */ 227 public BluetoothDevice getRemoteDevice(String address) { 228 return new BluetoothDevice(address); 229 } 230 231 /** 232 * Return true if Bluetooth is currently enabled and ready for use. 233 * <p>Equivalent to: 234 * <code>getBluetoothState() == STATE_ON</code> 235 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 236 * 237 * @return true if the local adapter is turned on 238 */ 239 public boolean isEnabled() { 240 try { 241 return mService.isEnabled(); 242 } catch (RemoteException e) {Log.e(TAG, "", e);} 243 return false; 244 } 245 246 /** 247 * Get the current state of the local Bluetooth adapter. 248 * <p>Possible return values are 249 * {@link #STATE_OFF}, 250 * {@link #STATE_TURNING_ON}, 251 * {@link #STATE_ON}, 252 * {@link #STATE_TURNING_OFF}. 253 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 254 * 255 * @return current state of Bluetooth adapter 256 */ 257 public int getState() { 258 try { 259 return mService.getBluetoothState(); 260 } catch (RemoteException e) {Log.e(TAG, "", e);} 261 return STATE_OFF; 262 } 263 264 /** 265 * Turn on the local Bluetooth adapter. 266 * <p>This powers on the underlying Bluetooth hardware, and starts all 267 * Bluetooth system services. 268 * <p>This is an asynchronous call: it will return immediatley, and 269 * clients should listen for {@link #ACTION_STATE_CHANGED} 270 * to be notified of subsequent adapter state changes. If this call returns 271 * true, then the adapter state will immediately transition from {@link 272 * #STATE_OFF} to {@link #STATE_TURNING_ON}, and some time 273 * later transition to either {@link #STATE_OFF} or {@link 274 * #STATE_ON}. If this call returns false then there was an 275 * immediate problem that will prevent the adapter from being turned on - 276 * such as Airplane mode, or the adapter is already turned on. 277 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 278 * 279 * @return true to indicate adapter startup has begun, or false on 280 * immediate error 281 */ 282 public boolean enable() { 283 try { 284 return mService.enable(); 285 } catch (RemoteException e) {Log.e(TAG, "", e);} 286 return false; 287 } 288 289 /** 290 * Turn off the local Bluetooth adapter. 291 * <p>This gracefully shuts down all Bluetooth connections, stops Bluetooth 292 * system services, and powers down the underlying Bluetooth hardware. 293 * <p>This is an asynchronous call: it will return immediatley, and 294 * clients should listen for {@link #ACTION_STATE_CHANGED} 295 * to be notified of subsequent adapter state changes. If this call returns 296 * true, then the adapter state will immediately transition from {@link 297 * #STATE_ON} to {@link #STATE_TURNING_OFF}, and some time 298 * later transition to either {@link #STATE_OFF} or {@link 299 * #STATE_ON}. If this call returns false then there was an 300 * immediate problem that will prevent the adapter from being turned off - 301 * such as the adapter already being turned off. 302 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 303 * 304 * @return true to indicate adapter shutdown has begun, or false on 305 * immediate error 306 */ 307 public boolean disable() { 308 try { 309 return mService.disable(true); 310 } catch (RemoteException e) {Log.e(TAG, "", e);} 311 return false; 312 } 313 314 /** 315 * Returns the hardware address of the local Bluetooth adapter. 316 * <p>For example, "00:11:22:AA:BB:CC". 317 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 318 * 319 * @return Bluetooth hardware address as string 320 */ 321 public String getAddress() { 322 try { 323 return mService.getAddress(); 324 } catch (RemoteException e) {Log.e(TAG, "", e);} 325 return null; 326 } 327 328 /** 329 * Get the friendly Bluetooth name of the local Bluetooth adapter. 330 * <p>This name is visible to remote Bluetooth devices. 331 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 332 * 333 * @return the Bluetooth name, or null on error 334 */ 335 public String getName() { 336 try { 337 return mService.getName(); 338 } catch (RemoteException e) {Log.e(TAG, "", e);} 339 return null; 340 } 341 342 /** 343 * Set the friendly Bluetooth name of the local Bluetoth adapter. 344 * <p>This name is visible to remote Bluetooth devices. 345 * <p>Valid Bluetooth names are a maximum of 248 UTF-8 characters, however 346 * many remote devices can only display the first 40 characters, and some 347 * may be limited to just 20. 348 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 349 * 350 * @param name a valid Bluetooth name 351 * @return true if the name was set, false otherwise 352 */ 353 public boolean setName(String name) { 354 try { 355 return mService.setName(name); 356 } catch (RemoteException e) {Log.e(TAG, "", e);} 357 return false; 358 } 359 360 /** 361 * Get the current Bluetooth scan mode of the local Bluetooth adaper. 362 * <p>The Bluetooth scan mode determines if the local adapter is 363 * connectable and/or discoverable from remote Bluetooth devices. 364 * <p>Possible values are: 365 * {@link #SCAN_MODE_NONE}, 366 * {@link #SCAN_MODE_CONNECTABLE}, 367 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}. 368 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 369 * 370 * @return scan mode 371 */ 372 public int getScanMode() { 373 try { 374 return mService.getScanMode(); 375 } catch (RemoteException e) {Log.e(TAG, "", e);} 376 return SCAN_MODE_NONE; 377 } 378 379 /** 380 * Set the Bluetooth scan mode of the local Bluetooth adapter. 381 * <p>The Bluetooth scan mode determines if the local adapter is 382 * connectable and/or discoverable from remote Bluetooth devices. 383 * <p>For privacy reasons, it is recommended to limit the duration of time 384 * that the local adapter remains in a discoverable scan mode. For example, 385 * 2 minutes is a generous time to allow a remote Bluetooth device to 386 * initiate and complete its discovery process. 387 * <p>Valid scan mode values are: 388 * {@link #SCAN_MODE_NONE}, 389 * {@link #SCAN_MODE_CONNECTABLE}, 390 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}. 391 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 392 * 393 * @param mode valid scan mode 394 * @return true if the scan mode was set, false otherwise 395 */ 396 public boolean setScanMode(int mode) { 397 try { 398 return mService.setScanMode(mode); 399 } catch (RemoteException e) {Log.e(TAG, "", e);} 400 return false; 401 } 402 403 /** @hide */ 404 public int getDiscoverableTimeout() { 405 try { 406 return mService.getDiscoverableTimeout(); 407 } catch (RemoteException e) {Log.e(TAG, "", e);} 408 return -1; 409 } 410 411 /** @hide */ 412 public void setDiscoverableTimeout(int timeout) { 413 try { 414 mService.setDiscoverableTimeout(timeout); 415 } catch (RemoteException e) {Log.e(TAG, "", e);} 416 } 417 418 /** 419 * Start the remote device discovery process. 420 * <p>The discovery process usually involves an inquiry scan of about 12 421 * seconds, followed by a page scan of each new device to retrieve its 422 * Bluetooth name. 423 * <p>This is an asynchronous call, it will return immediately. Register 424 * for {@link #ACTION_DISCOVERY_STARTED} and {@link 425 * #ACTION_DISCOVERY_FINISHED} intents to determine exactly when the 426 * discovery starts and completes. Register for {@link 427 * BluetoothDevice#ACTION_FOUND} to be notified as remote Bluetooth devices 428 * are found. 429 * <p>Device discovery is a heavyweight procedure. New connections to 430 * remote Bluetooth devices should not be attempted while discovery is in 431 * progress, and existing connections will experience limited bandwidth 432 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 433 * discovery. 434 * <p>Device discovery will only find remote devices that are currently 435 * <i>discoverable</i> (inquiry scan enabled). Many Bluetooth devices are 436 * not discoverable by default, and need to be entered into a special mode. 437 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}. 438 * 439 * @return true on success, false on error 440 */ 441 public boolean startDiscovery() { 442 try { 443 return mService.startDiscovery(); 444 } catch (RemoteException e) {Log.e(TAG, "", e);} 445 return false; 446 } 447 448 /** 449 * Cancel the current device discovery process. 450 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}. 451 * 452 * @return true on success, false on error 453 */ 454 public boolean cancelDiscovery() { 455 try { 456 mService.cancelDiscovery(); 457 } catch (RemoteException e) {Log.e(TAG, "", e);} 458 return false; 459 } 460 461 /** 462 * Return true if the local Bluetooth adapter is currently in the device 463 * discovery process. 464 * <p>Device discovery is a heavyweight procedure. New connections to 465 * remote Bluetooth devices should not be attempted while discovery is in 466 * progress, and existing connections will experience limited bandwidth 467 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 468 * discovery. 469 * <p>Applications can also register for {@link #ACTION_DISCOVERY_STARTED} 470 * or {@link #ACTION_DISCOVERY_FINISHED} to be notified when discovery 471 * starts or completes. 472 * 473 * @return true if discovering 474 */ 475 public boolean isDiscovering() { 476 try { 477 return mService.isDiscovering(); 478 } catch (RemoteException e) {Log.e(TAG, "", e);} 479 return false; 480 } 481 482 /** 483 * Return the set of {@link BluetoothDevice} objects that are bonded 484 * (paired) to the local adapter. 485 * 486 * @return unmodifiable set of {@link BluetoothDevice}, or null on error 487 */ 488 public Set<BluetoothDevice> getBondedDevices() { 489 try { 490 return toDeviceSet(mService.listBonds()); 491 } catch (RemoteException e) {Log.e(TAG, "", e);} 492 return null; 493 } 494 495 /** 496 * Create a listening, secure RFCOMM Bluetooth socket. 497 * <p>A remote device connecting to this socket will be authenticated and 498 * communication on this socket will be encrypted. 499 * <p>Use {@link BluetoothServerSocket#accept} to retrieve incoming 500 * connections to listening {@link BluetoothServerSocket}. 501 * <p>Valid RFCOMM channels are in range 1 to 30. 502 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 503 * @param channel RFCOMM channel to listen on 504 * @return a listening RFCOMM BluetoothServerSocket 505 * @throws IOException on error, for example Bluetooth not available, or 506 * insufficient permissions, or channel in use. 507 */ 508 public BluetoothServerSocket listenUsingRfcommOn(int channel) throws IOException { 509 BluetoothServerSocket socket = new BluetoothServerSocket( 510 BluetoothSocket.TYPE_RFCOMM, true, true, channel); 511 try { 512 socket.mSocket.bindListen(); 513 } catch (IOException e) { 514 try { 515 socket.close(); 516 } catch (IOException e2) { } 517 throw e; 518 } 519 return socket; 520 } 521 522 /** 523 * Construct an unencrypted, unauthenticated, RFCOMM server socket. 524 * Call #accept to retrieve connections to this socket. 525 * @return An RFCOMM BluetoothServerSocket 526 * @throws IOException On error, for example Bluetooth not available, or 527 * insufficient permissions. 528 * @hide 529 */ 530 public BluetoothServerSocket listenUsingInsecureRfcommOn(int port) throws IOException { 531 BluetoothServerSocket socket = new BluetoothServerSocket( 532 BluetoothSocket.TYPE_RFCOMM, false, false, port); 533 try { 534 socket.mSocket.bindListen(); 535 } catch (IOException e) { 536 try { 537 socket.close(); 538 } catch (IOException e2) { } 539 throw e; 540 } 541 return socket; 542 } 543 544 /** 545 * Construct a SCO server socket. 546 * Call #accept to retrieve connections to this socket. 547 * @return A SCO BluetoothServerSocket 548 * @throws IOException On error, for example Bluetooth not available, or 549 * insufficient permissions. 550 * @hide 551 */ 552 public static BluetoothServerSocket listenUsingScoOn() throws IOException { 553 BluetoothServerSocket socket = new BluetoothServerSocket( 554 BluetoothSocket.TYPE_SCO, false, false, -1); 555 try { 556 socket.mSocket.bindListen(); 557 } catch (IOException e) { 558 try { 559 socket.close(); 560 } catch (IOException e2) { } 561 throw e; 562 } 563 return socket; 564 } 565 566 private Set<BluetoothDevice> toDeviceSet(String[] addresses) { 567 Set<BluetoothDevice> devices = new HashSet<BluetoothDevice>(addresses.length); 568 for (int i = 0; i < addresses.length; i++) { 569 devices.add(getRemoteDevice(addresses[i])); 570 } 571 return Collections.unmodifiableSet(devices); 572 } 573 574 /** 575 * Validate a Bluetooth address, such as "00:43:A8:23:10:F0" 576 * <p>Alphabetic characters must be uppercase to be valid. 577 * 578 * @param address Bluetooth address as string 579 * @return true if the address is valid, false otherwise 580 */ 581 public static boolean checkBluetoothAddress(String address) { 582 if (address == null || address.length() != ADDRESS_LENGTH) { 583 return false; 584 } 585 for (int i = 0; i < ADDRESS_LENGTH; i++) { 586 char c = address.charAt(i); 587 switch (i % 3) { 588 case 0: 589 case 1: 590 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')) { 591 // hex character, OK 592 break; 593 } 594 return false; 595 case 2: 596 if (c == ':') { 597 break; // OK 598 } 599 return false; 600 } 601 } 602 return true; 603 } 604} 605