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 17 package android.bluetooth; 18 19 import android.annotation.SdkConstant; 20 import android.annotation.SdkConstant.SdkConstantType; 21 import android.os.Binder; 22 import android.os.Handler; 23 import android.os.IBinder; 24 import android.os.Message; 25 import android.os.ParcelUuid; 26 import android.os.RemoteException; 27 import android.os.ServiceManager; 28 import android.util.Log; 29 30 import java.io.IOException; 31 import java.util.Collections; 32 import java.util.HashSet; 33 import java.util.LinkedList; 34 import java.util.Random; 35 import java.util.Set; 36 import java.util.UUID; 37 38 /** 39 * Represents the local device Bluetooth adapter. The {@link BluetoothAdapter} 40 * lets you perform fundamental Bluetooth tasks, such as initiate 41 * device discovery, query a list of bonded (paired) devices, 42 * instantiate a {@link BluetoothDevice} using a known MAC address, and create 43 * a {@link BluetoothServerSocket} to listen for connection requests from other 44 * devices. 45 * 46 * <p>To get a {@link BluetoothAdapter} representing the local Bluetooth 47 * adapter, call the static {@link #getDefaultAdapter} method. 48 * Fundamentally, this is your starting point for all 49 * Bluetooth actions. Once you have the local adapter, you can get a set of 50 * {@link BluetoothDevice} objects representing all paired devices with 51 * {@link #getBondedDevices()}; start device discovery with 52 * {@link #startDiscovery()}; or create a {@link BluetoothServerSocket} to 53 * listen for incoming connection requests with 54 * {@link #listenUsingRfcommWithServiceRecord(String,UUID)}. 55 * 56 * <p class="note"><strong>Note:</strong> 57 * Most methods require the {@link android.Manifest.permission#BLUETOOTH} 58 * permission and some also require the 59 * {@link android.Manifest.permission#BLUETOOTH_ADMIN} permission. 60 * 61 * {@see BluetoothDevice} 62 * {@see BluetoothServerSocket} 63 */ 64 public final class BluetoothAdapter { 65 private static final String TAG = "BluetoothAdapter"; 66 private static final boolean DBG = false; 67 68 /** 69 * Sentinel error value for this class. Guaranteed to not equal any other 70 * integer constant in this class. Provided as a convenience for functions 71 * that require a sentinel error value, for example: 72 * <p><code>Intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 73 * BluetoothAdapter.ERROR)</code> 74 */ 75 public static final int ERROR = Integer.MIN_VALUE; 76 77 /** 78 * Broadcast Action: The state of the local Bluetooth adapter has been 79 * changed. 80 * <p>For example, Bluetooth has been turned on or off. 81 * <p>Always contains the extra fields {@link #EXTRA_STATE} and {@link 82 * #EXTRA_PREVIOUS_STATE} containing the new and old states 83 * respectively. 84 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 85 */ 86 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 87 public static final String ACTION_STATE_CHANGED = 88 "android.bluetooth.adapter.action.STATE_CHANGED"; 89 90 /** 91 * Used as an int extra field in {@link #ACTION_STATE_CHANGED} 92 * intents to request the current power state. Possible values are: 93 * {@link #STATE_OFF}, 94 * {@link #STATE_TURNING_ON}, 95 * {@link #STATE_ON}, 96 * {@link #STATE_TURNING_OFF}, 97 */ 98 public static final String EXTRA_STATE = 99 "android.bluetooth.adapter.extra.STATE"; 100 /** 101 * Used as an int extra field in {@link #ACTION_STATE_CHANGED} 102 * intents to request the previous power state. Possible values are: 103 * {@link #STATE_OFF}, 104 * {@link #STATE_TURNING_ON}, 105 * {@link #STATE_ON}, 106 * {@link #STATE_TURNING_OFF}, 107 */ 108 public static final String EXTRA_PREVIOUS_STATE = 109 "android.bluetooth.adapter.extra.PREVIOUS_STATE"; 110 111 /** 112 * Indicates the local Bluetooth adapter is off. 113 */ 114 public static final int STATE_OFF = 10; 115 /** 116 * Indicates the local Bluetooth adapter is turning on. However local 117 * clients should wait for {@link #STATE_ON} before attempting to 118 * use the adapter. 119 */ 120 public static final int STATE_TURNING_ON = 11; 121 /** 122 * Indicates the local Bluetooth adapter is on, and ready for use. 123 */ 124 public static final int STATE_ON = 12; 125 /** 126 * Indicates the local Bluetooth adapter is turning off. Local clients 127 * should immediately attempt graceful disconnection of any remote links. 128 */ 129 public static final int STATE_TURNING_OFF = 13; 130 131 /** 132 * Activity Action: Show a system activity that requests discoverable mode. 133 * This activity will also request the user to turn on Bluetooth if it 134 * is not currently enabled. 135 * <p>Discoverable mode is equivalent to {@link 136 * #SCAN_MODE_CONNECTABLE_DISCOVERABLE}. It allows remote devices to see 137 * this Bluetooth adapter when they perform a discovery. 138 * <p>For privacy, Android is not discoverable by default. 139 * <p>The sender of this Intent can optionally use extra field {@link 140 * #EXTRA_DISCOVERABLE_DURATION} to request the duration of 141 * discoverability. Currently the default duration is 120 seconds, and 142 * maximum duration is capped at 300 seconds for each request. 143 * <p>Notification of the result of this activity is posted using the 144 * {@link android.app.Activity#onActivityResult} callback. The 145 * <code>resultCode</code> 146 * will be the duration (in seconds) of discoverability or 147 * {@link android.app.Activity#RESULT_CANCELED} if the user rejected 148 * discoverability or an error has occurred. 149 * <p>Applications can also listen for {@link #ACTION_SCAN_MODE_CHANGED} 150 * for global notification whenever the scan mode changes. For example, an 151 * application can be notified when the device has ended discoverability. 152 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 153 */ 154 @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION) 155 public static final String ACTION_REQUEST_DISCOVERABLE = 156 "android.bluetooth.adapter.action.REQUEST_DISCOVERABLE"; 157 158 /** 159 * Used as an optional int extra field in {@link 160 * #ACTION_REQUEST_DISCOVERABLE} intents to request a specific duration 161 * for discoverability in seconds. The current default is 120 seconds, and 162 * requests over 300 seconds will be capped. These values could change. 163 */ 164 public static final String EXTRA_DISCOVERABLE_DURATION = 165 "android.bluetooth.adapter.extra.DISCOVERABLE_DURATION"; 166 167 /** 168 * Activity Action: Show a system activity that allows the user to turn on 169 * Bluetooth. 170 * <p>This system activity will return once Bluetooth has completed turning 171 * on, or the user has decided not to turn Bluetooth on. 172 * <p>Notification of the result of this activity is posted using the 173 * {@link android.app.Activity#onActivityResult} callback. The 174 * <code>resultCode</code> 175 * will be {@link android.app.Activity#RESULT_OK} if Bluetooth has been 176 * turned on or {@link android.app.Activity#RESULT_CANCELED} if the user 177 * has rejected the request or an error has occurred. 178 * <p>Applications can also listen for {@link #ACTION_STATE_CHANGED} 179 * for global notification whenever Bluetooth is turned on or off. 180 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 181 */ 182 @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION) 183 public static final String ACTION_REQUEST_ENABLE = 184 "android.bluetooth.adapter.action.REQUEST_ENABLE"; 185 186 /** 187 * Broadcast Action: Indicates the Bluetooth scan mode of the local Adapter 188 * has changed. 189 * <p>Always contains the extra fields {@link #EXTRA_SCAN_MODE} and {@link 190 * #EXTRA_PREVIOUS_SCAN_MODE} containing the new and old scan modes 191 * respectively. 192 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 193 */ 194 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 195 public static final String ACTION_SCAN_MODE_CHANGED = 196 "android.bluetooth.adapter.action.SCAN_MODE_CHANGED"; 197 198 /** 199 * Used as an int extra field in {@link #ACTION_SCAN_MODE_CHANGED} 200 * intents to request the current scan mode. Possible values are: 201 * {@link #SCAN_MODE_NONE}, 202 * {@link #SCAN_MODE_CONNECTABLE}, 203 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}, 204 */ 205 public static final String EXTRA_SCAN_MODE = "android.bluetooth.adapter.extra.SCAN_MODE"; 206 /** 207 * Used as an int extra field in {@link #ACTION_SCAN_MODE_CHANGED} 208 * intents to request the previous scan mode. Possible values are: 209 * {@link #SCAN_MODE_NONE}, 210 * {@link #SCAN_MODE_CONNECTABLE}, 211 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}, 212 */ 213 public static final String EXTRA_PREVIOUS_SCAN_MODE = 214 "android.bluetooth.adapter.extra.PREVIOUS_SCAN_MODE"; 215 216 /** 217 * Indicates that both inquiry scan and page scan are disabled on the local 218 * Bluetooth adapter. Therefore this device is neither discoverable 219 * nor connectable from remote Bluetooth devices. 220 */ 221 public static final int SCAN_MODE_NONE = 20; 222 /** 223 * Indicates that inquiry scan is disabled, but page scan is enabled on the 224 * local Bluetooth adapter. Therefore this device is not discoverable from 225 * remote Bluetooth devices, but is connectable from remote devices that 226 * have previously discovered this device. 227 */ 228 public static final int SCAN_MODE_CONNECTABLE = 21; 229 /** 230 * Indicates that both inquiry scan and page scan are enabled on the local 231 * Bluetooth adapter. Therefore this device is both discoverable and 232 * connectable from remote Bluetooth devices. 233 */ 234 public static final int SCAN_MODE_CONNECTABLE_DISCOVERABLE = 23; 235 236 237 /** 238 * Broadcast Action: The local Bluetooth adapter has started the remote 239 * device discovery process. 240 * <p>This usually involves an inquiry scan of about 12 seconds, followed 241 * by a page scan of each new device to retrieve its Bluetooth name. 242 * <p>Register for {@link BluetoothDevice#ACTION_FOUND} to be notified as 243 * remote Bluetooth devices are found. 244 * <p>Device discovery is a heavyweight procedure. New connections to 245 * remote Bluetooth devices should not be attempted while discovery is in 246 * progress, and existing connections will experience limited bandwidth 247 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 248 * discovery. 249 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 250 */ 251 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 252 public static final String ACTION_DISCOVERY_STARTED = 253 "android.bluetooth.adapter.action.DISCOVERY_STARTED"; 254 /** 255 * Broadcast Action: The local Bluetooth adapter has finished the device 256 * discovery process. 257 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 258 */ 259 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 260 public static final String ACTION_DISCOVERY_FINISHED = 261 "android.bluetooth.adapter.action.DISCOVERY_FINISHED"; 262 263 /** 264 * Broadcast Action: The local Bluetooth adapter has changed its friendly 265 * Bluetooth name. 266 * <p>This name is visible to remote Bluetooth devices. 267 * <p>Always contains the extra field {@link #EXTRA_LOCAL_NAME} containing 268 * the name. 269 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 270 */ 271 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 272 public static final String ACTION_LOCAL_NAME_CHANGED = 273 "android.bluetooth.adapter.action.LOCAL_NAME_CHANGED"; 274 /** 275 * Used as a String extra field in {@link #ACTION_LOCAL_NAME_CHANGED} 276 * intents to request the local Bluetooth name. 277 */ 278 public static final String EXTRA_LOCAL_NAME = "android.bluetooth.adapter.extra.LOCAL_NAME"; 279 280 /** @hide */ 281 public static final String BLUETOOTH_SERVICE = "bluetooth"; 282 283 private static final int ADDRESS_LENGTH = 17; 284 285 /** 286 * Lazyily initialized singleton. Guaranteed final after first object 287 * constructed. 288 */ 289 private static BluetoothAdapter sAdapter; 290 291 private final IBluetooth mService; 292 293 /** 294 * Get a handle to the default local Bluetooth adapter. 295 * <p>Currently Android only supports one Bluetooth adapter, but the API 296 * could be extended to support more. This will always return the default 297 * adapter. 298 * @return the default local adapter, or null if Bluetooth is not supported 299 * on this hardware platform 300 */ 301 public static synchronized BluetoothAdapter getDefaultAdapter() { 302 if (sAdapter == null) { 303 IBinder b = ServiceManager.getService(BluetoothAdapter.BLUETOOTH_SERVICE); 304 if (b != null) { 305 IBluetooth service = IBluetooth.Stub.asInterface(b); 306 sAdapter = new BluetoothAdapter(service); 307 } 308 } 309 return sAdapter; 310 } 311 312 /** 313 * Use {@link #getDefaultAdapter} to get the BluetoothAdapter instance. 314 * @hide 315 */ 316 public BluetoothAdapter(IBluetooth service) { 317 if (service == null) { 318 throw new IllegalArgumentException("service is null"); 319 } 320 mService = service; 321 } 322 323 /** 324 * Get a {@link BluetoothDevice} object for the given Bluetooth hardware 325 * address. 326 * <p>Valid Bluetooth hardware addresses must be upper case, in a format 327 * such as "00:11:22:33:AA:BB". The helper {@link #checkBluetoothAddress} is 328 * available to validate a Bluetooth address. 329 * <p>A {@link BluetoothDevice} will always be returned for a valid 330 * hardware address, even if this adapter has never seen that device. 331 * 332 * @param address valid Bluetooth MAC address 333 * @throws IllegalArgumentException if address is invalid 334 */ 335 public BluetoothDevice getRemoteDevice(String address) { 336 return new BluetoothDevice(address); 337 } 338 339 /** 340 * Return true if Bluetooth is currently enabled and ready for use. 341 * <p>Equivalent to: 342 * <code>getBluetoothState() == STATE_ON</code> 343 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 344 * 345 * @return true if the local adapter is turned on 346 */ 347 public boolean isEnabled() { 348 try { 349 return mService.isEnabled(); 350 } catch (RemoteException e) {Log.e(TAG, "", e);} 351 return false; 352 } 353 354 /** 355 * Get the current state of the local Bluetooth adapter. 356 * <p>Possible return values are 357 * {@link #STATE_OFF}, 358 * {@link #STATE_TURNING_ON}, 359 * {@link #STATE_ON}, 360 * {@link #STATE_TURNING_OFF}. 361 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 362 * 363 * @return current state of Bluetooth adapter 364 */ 365 public int getState() { 366 try { 367 return mService.getBluetoothState(); 368 } catch (RemoteException e) {Log.e(TAG, "", e);} 369 return STATE_OFF; 370 } 371 372 /** 373 * Turn on the local Bluetooth adapter—do not use without explicit 374 * user action to turn on Bluetooth. 375 * <p>This powers on the underlying Bluetooth hardware, and starts all 376 * Bluetooth system services. 377 * <p class="caution"><strong>Bluetooth should never be enabled without 378 * direct user consent</strong>. If you want to turn on Bluetooth in order 379 * to create a wireless connection, you should use the {@link 380 * #ACTION_REQUEST_ENABLE} Intent, which will raise a dialog that requests 381 * user permission to turn on Bluetooth. The {@link #enable()} method is 382 * provided only for applications that include a user interface for changing 383 * system settings, such as a "power manager" app.</p> 384 * <p>This is an asynchronous call: it will return immediately, and 385 * clients should listen for {@link #ACTION_STATE_CHANGED} 386 * to be notified of subsequent adapter state changes. If this call returns 387 * true, then the adapter state will immediately transition from {@link 388 * #STATE_OFF} to {@link #STATE_TURNING_ON}, and some time 389 * later transition to either {@link #STATE_OFF} or {@link 390 * #STATE_ON}. If this call returns false then there was an 391 * immediate problem that will prevent the adapter from being turned on - 392 * such as Airplane mode, or the adapter is already turned on. 393 * <p>Requires the {@link android.Manifest.permission#BLUETOOTH_ADMIN} 394 * permission 395 * 396 * @return true to indicate adapter startup has begun, or false on 397 * immediate error 398 */ 399 public boolean enable() { 400 try { 401 return mService.enable(); 402 } catch (RemoteException e) {Log.e(TAG, "", e);} 403 return false; 404 } 405 406 /** 407 * Turn off the local Bluetooth adapter—do not use without explicit 408 * user action to turn off Bluetooth. 409 * <p>This gracefully shuts down all Bluetooth connections, stops Bluetooth 410 * system services, and powers down the underlying Bluetooth hardware. 411 * <p class="caution"><strong>Bluetooth should never be disbled without 412 * direct user consent</strong>. The {@link #disable()} method is 413 * provided only for applications that include a user interface for changing 414 * system settings, such as a "power manager" app.</p> 415 * <p>This is an asynchronous call: it will return immediately, and 416 * clients should listen for {@link #ACTION_STATE_CHANGED} 417 * to be notified of subsequent adapter state changes. If this call returns 418 * true, then the adapter state will immediately transition from {@link 419 * #STATE_ON} to {@link #STATE_TURNING_OFF}, and some time 420 * later transition to either {@link #STATE_OFF} or {@link 421 * #STATE_ON}. If this call returns false then there was an 422 * immediate problem that will prevent the adapter from being turned off - 423 * such as the adapter already being turned off. 424 * <p>Requires the {@link android.Manifest.permission#BLUETOOTH_ADMIN} 425 * permission 426 * 427 * @return true to indicate adapter shutdown has begun, or false on 428 * immediate error 429 */ 430 public boolean disable() { 431 try { 432 return mService.disable(true); 433 } catch (RemoteException e) {Log.e(TAG, "", e);} 434 return false; 435 } 436 437 /** 438 * Returns the hardware address of the local Bluetooth adapter. 439 * <p>For example, "00:11:22:AA:BB:CC". 440 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 441 * 442 * @return Bluetooth hardware address as string 443 */ 444 public String getAddress() { 445 try { 446 return mService.getAddress(); 447 } catch (RemoteException e) {Log.e(TAG, "", e);} 448 return null; 449 } 450 451 /** 452 * Get the friendly Bluetooth name of the local Bluetooth adapter. 453 * <p>This name is visible to remote Bluetooth devices. 454 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 455 * 456 * @return the Bluetooth name, or null on error 457 */ 458 public String getName() { 459 try { 460 return mService.getName(); 461 } catch (RemoteException e) {Log.e(TAG, "", e);} 462 return null; 463 } 464 465 /** 466 * Set the friendly Bluetooth name of the local Bluetoth adapter. 467 * <p>This name is visible to remote Bluetooth devices. 468 * <p>Valid Bluetooth names are a maximum of 248 UTF-8 characters, however 469 * many remote devices can only display the first 40 characters, and some 470 * may be limited to just 20. 471 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 472 * 473 * @param name a valid Bluetooth name 474 * @return true if the name was set, false otherwise 475 */ 476 public boolean setName(String name) { 477 try { 478 return mService.setName(name); 479 } catch (RemoteException e) {Log.e(TAG, "", e);} 480 return false; 481 } 482 483 /** 484 * Get the current Bluetooth scan mode of the local Bluetooth adaper. 485 * <p>The Bluetooth scan mode determines if the local adapter is 486 * connectable and/or discoverable from remote Bluetooth devices. 487 * <p>Possible values are: 488 * {@link #SCAN_MODE_NONE}, 489 * {@link #SCAN_MODE_CONNECTABLE}, 490 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}. 491 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 492 * 493 * @return scan mode 494 */ 495 public int getScanMode() { 496 try { 497 return mService.getScanMode(); 498 } catch (RemoteException e) {Log.e(TAG, "", e);} 499 return SCAN_MODE_NONE; 500 } 501 502 /** 503 * Set the Bluetooth scan mode of the local Bluetooth adapter. 504 * <p>The Bluetooth scan mode determines if the local adapter is 505 * connectable and/or discoverable from remote Bluetooth devices. 506 * <p>For privacy reasons, discoverable mode is automatically turned off 507 * after <code>duration</code> seconds. For example, 120 seconds should be 508 * enough for a remote device to initiate and complete its discovery 509 * process. 510 * <p>Valid scan mode values are: 511 * {@link #SCAN_MODE_NONE}, 512 * {@link #SCAN_MODE_CONNECTABLE}, 513 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}. 514 * <p>Requires {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} 515 * <p>Applications cannot set the scan mode. They should use 516 * <code>startActivityForResult( 517 * BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE}) 518 * </code>instead. 519 * 520 * @param mode valid scan mode 521 * @param duration time in seconds to apply scan mode, only used for 522 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE} 523 * @return true if the scan mode was set, false otherwise 524 * @hide 525 */ 526 public boolean setScanMode(int mode, int duration) { 527 try { 528 return mService.setScanMode(mode, duration); 529 } catch (RemoteException e) {Log.e(TAG, "", e);} 530 return false; 531 } 532 533 /** @hide */ 534 public boolean setScanMode(int mode) { 535 return setScanMode(mode, 120); 536 } 537 538 /** @hide */ 539 public int getDiscoverableTimeout() { 540 try { 541 return mService.getDiscoverableTimeout(); 542 } catch (RemoteException e) {Log.e(TAG, "", e);} 543 return -1; 544 } 545 546 /** @hide */ 547 public void setDiscoverableTimeout(int timeout) { 548 try { 549 mService.setDiscoverableTimeout(timeout); 550 } catch (RemoteException e) {Log.e(TAG, "", e);} 551 } 552 553 /** 554 * Start the remote device discovery process. 555 * <p>The discovery process usually involves an inquiry scan of about 12 556 * seconds, followed by a page scan of each new device to retrieve its 557 * Bluetooth name. 558 * <p>This is an asynchronous call, it will return immediately. Register 559 * for {@link #ACTION_DISCOVERY_STARTED} and {@link 560 * #ACTION_DISCOVERY_FINISHED} intents to determine exactly when the 561 * discovery starts and completes. Register for {@link 562 * BluetoothDevice#ACTION_FOUND} to be notified as remote Bluetooth devices 563 * are found. 564 * <p>Device discovery is a heavyweight procedure. New connections to 565 * remote Bluetooth devices should not be attempted while discovery is in 566 * progress, and existing connections will experience limited bandwidth 567 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 568 * discovery. Discovery is not managed by the Activity, 569 * but is run as a system service, so an application should always call 570 * {@link BluetoothAdapter#cancelDiscovery()} even if it 571 * did not directly request a discovery, just to be sure. 572 * <p>Device discovery will only find remote devices that are currently 573 * <i>discoverable</i> (inquiry scan enabled). Many Bluetooth devices are 574 * not discoverable by default, and need to be entered into a special mode. 575 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}. 576 * 577 * @return true on success, false on error 578 */ 579 public boolean startDiscovery() { 580 try { 581 return mService.startDiscovery(); 582 } catch (RemoteException e) {Log.e(TAG, "", e);} 583 return false; 584 } 585 586 /** 587 * Cancel the current device discovery process. 588 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}. 589 * <p>Because discovery is a heavyweight precedure for the Bluetooth 590 * adapter, this method should always be called before attempting to connect 591 * to a remote device with {@link 592 * android.bluetooth.BluetoothSocket#connect()}. Discovery is not managed by 593 * the Activity, but is run as a system service, so an application should 594 * always call cancel discovery even if it did not directly request a 595 * discovery, just to be sure. 596 * 597 * @return true on success, false on error 598 */ 599 public boolean cancelDiscovery() { 600 try { 601 mService.cancelDiscovery(); 602 } catch (RemoteException e) {Log.e(TAG, "", e);} 603 return false; 604 } 605 606 /** 607 * Return true if the local Bluetooth adapter is currently in the device 608 * discovery process. 609 * <p>Device discovery is a heavyweight procedure. New connections to 610 * remote Bluetooth devices should not be attempted while discovery is in 611 * progress, and existing connections will experience limited bandwidth 612 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 613 * discovery. 614 * <p>Applications can also register for {@link #ACTION_DISCOVERY_STARTED} 615 * or {@link #ACTION_DISCOVERY_FINISHED} to be notified when discovery 616 * starts or completes. 617 * <p>Requires {@link android.Manifest.permission#BLUETOOTH}. 618 * 619 * @return true if discovering 620 */ 621 public boolean isDiscovering() { 622 try { 623 return mService.isDiscovering(); 624 } catch (RemoteException e) {Log.e(TAG, "", e);} 625 return false; 626 } 627 628 /** 629 * Return the set of {@link BluetoothDevice} objects that are bonded 630 * (paired) to the local adapter. 631 * <p>Requires {@link android.Manifest.permission#BLUETOOTH}. 632 * 633 * @return unmodifiable set of {@link BluetoothDevice}, or null on error 634 */ 635 public Set<BluetoothDevice> getBondedDevices() { 636 try { 637 return toDeviceSet(mService.listBonds()); 638 } catch (RemoteException e) {Log.e(TAG, "", e);} 639 return null; 640 } 641 642 /** 643 * Picks RFCOMM channels until none are left. 644 * Avoids reserved channels. 645 */ 646 private static class RfcommChannelPicker { 647 private static final int[] RESERVED_RFCOMM_CHANNELS = new int[] { 648 10, // HFAG 649 11, // HSAG 650 12, // OPUSH 651 19, // PBAP 652 }; 653 private static LinkedList<Integer> sChannels; // master list of non-reserved channels 654 private static Random sRandom; 655 656 private final LinkedList<Integer> mChannels; // local list of channels left to try 657 658 private final UUID mUuid; 659 660 public RfcommChannelPicker(UUID uuid) { 661 synchronized (RfcommChannelPicker.class) { 662 if (sChannels == null) { 663 // lazy initialization of non-reserved rfcomm channels 664 sChannels = new LinkedList<Integer>(); 665 for (int i = 1; i <= BluetoothSocket.MAX_RFCOMM_CHANNEL; i++) { 666 sChannels.addLast(new Integer(i)); 667 } 668 for (int reserved : RESERVED_RFCOMM_CHANNELS) { 669 sChannels.remove(new Integer(reserved)); 670 } 671 sRandom = new Random(); 672 } 673 mChannels = (LinkedList<Integer>)sChannels.clone(); 674 } 675 mUuid = uuid; 676 } 677 /* Returns next random channel, or -1 if we're out */ 678 public int nextChannel() { 679 if (mChannels.size() == 0) { 680 return -1; 681 } 682 return mChannels.remove(sRandom.nextInt(mChannels.size())); 683 } 684 } 685 686 /** 687 * Create a listening, secure RFCOMM Bluetooth socket. 688 * <p>A remote device connecting to this socket will be authenticated and 689 * communication on this socket will be encrypted. 690 * <p>Use {@link BluetoothServerSocket#accept} to retrieve incoming 691 * connections from a listening {@link BluetoothServerSocket}. 692 * <p>Valid RFCOMM channels are in range 1 to 30. 693 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 694 * @param channel RFCOMM channel to listen on 695 * @return a listening RFCOMM BluetoothServerSocket 696 * @throws IOException on error, for example Bluetooth not available, or 697 * insufficient permissions, or channel in use. 698 * @hide 699 */ 700 public BluetoothServerSocket listenUsingRfcommOn(int channel) throws IOException { 701 BluetoothServerSocket socket = new BluetoothServerSocket( 702 BluetoothSocket.TYPE_RFCOMM, true, true, channel); 703 int errno = socket.mSocket.bindListen(); 704 if (errno != 0) { 705 try { 706 socket.close(); 707 } catch (IOException e) {} 708 socket.mSocket.throwErrnoNative(errno); 709 } 710 return socket; 711 } 712 713 /** 714 * Create a listening, secure RFCOMM Bluetooth socket with Service Record. 715 * <p>A remote device connecting to this socket will be authenticated and 716 * communication on this socket will be encrypted. 717 * <p>Use {@link BluetoothServerSocket#accept} to retrieve incoming 718 * connections from a listening {@link BluetoothServerSocket}. 719 * <p>The system will assign an unused RFCOMM channel to listen on. 720 * <p>The system will also register a Service Discovery 721 * Protocol (SDP) record with the local SDP server containing the specified 722 * UUID, service name, and auto-assigned channel. Remote Bluetooth devices 723 * can use the same UUID to query our SDP server and discover which channel 724 * to connect to. This SDP record will be removed when this socket is 725 * closed, or if this application closes unexpectedly. 726 * <p>Use {@link BluetoothDevice#createRfcommSocketToServiceRecord} to 727 * connect to this socket from another device using the same {@link UUID}. 728 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 729 * @param name service name for SDP record 730 * @param uuid uuid for SDP record 731 * @return a listening RFCOMM BluetoothServerSocket 732 * @throws IOException on error, for example Bluetooth not available, or 733 * insufficient permissions, or channel in use. 734 */ 735 public BluetoothServerSocket listenUsingRfcommWithServiceRecord(String name, UUID uuid) 736 throws IOException { 737 RfcommChannelPicker picker = new RfcommChannelPicker(uuid); 738 739 BluetoothServerSocket socket; 740 int channel; 741 int errno; 742 while (true) { 743 channel = picker.nextChannel(); 744 745 if (channel == -1) { 746 throw new IOException("No available channels"); 747 } 748 749 socket = new BluetoothServerSocket( 750 BluetoothSocket.TYPE_RFCOMM, true, true, channel); 751 errno = socket.mSocket.bindListen(); 752 if (errno == 0) { 753 if (DBG) Log.d(TAG, "listening on RFCOMM channel " + channel); 754 break; // success 755 } else if (errno == BluetoothSocket.EADDRINUSE) { 756 if (DBG) Log.d(TAG, "RFCOMM channel " + channel + " in use"); 757 try { 758 socket.close(); 759 } catch (IOException e) {} 760 continue; // try another channel 761 } else { 762 try { 763 socket.close(); 764 } catch (IOException e) {} 765 socket.mSocket.throwErrnoNative(errno); // Exception as a result of bindListen() 766 } 767 } 768 769 int handle = -1; 770 try { 771 handle = mService.addRfcommServiceRecord(name, new ParcelUuid(uuid), channel, 772 new Binder()); 773 } catch (RemoteException e) {Log.e(TAG, "", e);} 774 if (handle == -1) { 775 try { 776 socket.close(); 777 } catch (IOException e) {} 778 throw new IOException("Not able to register SDP record for " + name); 779 } 780 socket.setCloseHandler(mHandler, handle); 781 return socket; 782 } 783 784 /** 785 * Construct an unencrypted, unauthenticated, RFCOMM server socket. 786 * Call #accept to retrieve connections to this socket. 787 * @return An RFCOMM BluetoothServerSocket 788 * @throws IOException On error, for example Bluetooth not available, or 789 * insufficient permissions. 790 * @hide 791 */ 792 public BluetoothServerSocket listenUsingInsecureRfcommOn(int port) throws IOException { 793 BluetoothServerSocket socket = new BluetoothServerSocket( 794 BluetoothSocket.TYPE_RFCOMM, false, false, port); 795 int errno = socket.mSocket.bindListen(); 796 if (errno != 0) { 797 try { 798 socket.close(); 799 } catch (IOException e) {} 800 socket.mSocket.throwErrnoNative(errno); 801 } 802 return socket; 803 } 804 805 /** 806 * Construct a SCO server socket. 807 * Call #accept to retrieve connections to this socket. 808 * @return A SCO BluetoothServerSocket 809 * @throws IOException On error, for example Bluetooth not available, or 810 * insufficient permissions. 811 * @hide 812 */ 813 public static BluetoothServerSocket listenUsingScoOn() throws IOException { 814 BluetoothServerSocket socket = new BluetoothServerSocket( 815 BluetoothSocket.TYPE_SCO, false, false, -1); 816 int errno = socket.mSocket.bindListen(); 817 if (errno != 0) { 818 try { 819 socket.close(); 820 } catch (IOException e) {} 821 socket.mSocket.throwErrnoNative(errno); 822 } 823 return socket; 824 } 825 826 private Set<BluetoothDevice> toDeviceSet(String[] addresses) { 827 Set<BluetoothDevice> devices = new HashSet<BluetoothDevice>(addresses.length); 828 for (int i = 0; i < addresses.length; i++) { 829 devices.add(getRemoteDevice(addresses[i])); 830 } 831 return Collections.unmodifiableSet(devices); 832 } 833 834 private Handler mHandler = new Handler() { 835 public void handleMessage(Message msg) { 836 /* handle socket closing */ 837 int handle = msg.what; 838 try { 839 if (DBG) Log.d(TAG, "Removing service record " + Integer.toHexString(handle)); 840 mService.removeServiceRecord(handle); 841 } catch (RemoteException e) {Log.e(TAG, "", e);} 842 } 843 }; 844 845 /** 846 * Validate a Bluetooth address, such as "00:43:A8:23:10:F0" 847 * <p>Alphabetic characters must be uppercase to be valid. 848 * 849 * @param address Bluetooth address as string 850 * @return true if the address is valid, false otherwise 851 */ 852 public static boolean checkBluetoothAddress(String address) { 853 if (address == null || address.length() != ADDRESS_LENGTH) { 854 return false; 855 } 856 for (int i = 0; i < ADDRESS_LENGTH; i++) { 857 char c = address.charAt(i); 858 switch (i % 3) { 859 case 0: 860 case 1: 861 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')) { 862 // hex character, OK 863 break; 864 } 865 return false; 866 case 2: 867 if (c == ':') { 868 break; // OK 869 } 870 return false; 871 } 872 } 873 return true; 874 } 875 } 876
