BluetoothAdapter.java revision 9fab0aef19a4633d2e4670564e5d7ae9e52fe11f
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.Binder; 22import android.os.Handler; 23import android.os.IBinder; 24import android.os.Message; 25import android.os.ParcelUuid; 26import android.os.RemoteException; 27import android.os.ServiceManager; 28import android.util.Log; 29 30import java.io.IOException; 31import java.util.Collections; 32import java.util.HashSet; 33import java.util.LinkedList; 34import java.util.Random; 35import java.util.Set; 36import 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 */ 64public 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 * <p>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 by default discoverable. 139 * <p>The sender 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 a negative 147 * value if the user rejected discoverability. 148 * <p>Applications can also listen for {@link #ACTION_SCAN_MODE_CHANGED} 149 * for global notification whenever the scan mode changes. 150 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 151 */ 152 @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION) 153 public static final String ACTION_REQUEST_DISCOVERABLE = 154 "android.bluetooth.adapter.action.REQUEST_DISCOVERABLE"; 155 156 /** 157 * Used as an optional int extra field in {@link 158 * #ACTION_REQUEST_DISCOVERABLE} intents to request a specific duration 159 * for discoverability in seconds. The current default is 120 seconds, and 160 * requests over 300 seconds will be capped. These values could change. 161 */ 162 public static final String EXTRA_DISCOVERABLE_DURATION = 163 "android.bluetooth.adapter.extra.DISCOVERABLE_DURATION"; 164 165 /** 166 * Activity Action: Show a system activity that allows the user to turn on 167 * Bluetooth. 168 * <p>This system activity will return once Bluetooth has completed turning 169 * on, or the user has decided not to turn Bluetooth on. 170 * <p>Notification of the result of this activity is posted using the 171 * {@link android.app.Activity#onActivityResult} callback. The 172 * <code>resultCode</code> 173 * will be negative if the user did not turn on Bluetooth, and non-negative 174 * if Bluetooth has been turned on. 175 * <p>Applications can also listen for {@link #ACTION_STATE_CHANGED} 176 * for global notification whenever Bluetooth is turned on or off. 177 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 178 */ 179 @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION) 180 public static final String ACTION_REQUEST_ENABLE = 181 "android.bluetooth.adapter.action.REQUEST_ENABLE"; 182 183 /** 184 * Broadcast Action: Indicates the Bluetooth scan mode of the local Adapter 185 * has changed. 186 * <p>Always contains the extra fields {@link #EXTRA_SCAN_MODE} and {@link 187 * #EXTRA_PREVIOUS_SCAN_MODE} containing the new and old scan modes 188 * respectively. 189 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 190 */ 191 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 192 public static final String ACTION_SCAN_MODE_CHANGED = 193 "android.bluetooth.adapter.action.SCAN_MODE_CHANGED"; 194 195 /** 196 * Used as an int extra field in {@link #ACTION_SCAN_MODE_CHANGED} 197 * intents to request the current scan mode. Possible values are: 198 * {@link #SCAN_MODE_NONE}, 199 * {@link #SCAN_MODE_CONNECTABLE}, 200 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}, 201 */ 202 public static final String EXTRA_SCAN_MODE = "android.bluetooth.adapter.extra.SCAN_MODE"; 203 /** 204 * Used as an int extra field in {@link #ACTION_SCAN_MODE_CHANGED} 205 * intents to request the previous scan mode. Possible values are: 206 * {@link #SCAN_MODE_NONE}, 207 * {@link #SCAN_MODE_CONNECTABLE}, 208 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}, 209 */ 210 public static final String EXTRA_PREVIOUS_SCAN_MODE = 211 "android.bluetooth.adapter.extra.PREVIOUS_SCAN_MODE"; 212 213 /** 214 * Indicates that both inquiry scan and page scan are disabled on the local 215 * Bluetooth adapter. Therefore this device is neither discoverable 216 * nor connectable from remote Bluetooth devices. 217 */ 218 public static final int SCAN_MODE_NONE = 20; 219 /** 220 * Indicates that inquiry scan is disabled, but page scan is enabled on the 221 * local Bluetooth adapter. Therefore this device is not discoverable from 222 * remote Bluetooth devices, but is connectable from remote devices that 223 * have previously discovered this device. 224 */ 225 public static final int SCAN_MODE_CONNECTABLE = 21; 226 /** 227 * Indicates that both inquiry scan and page scan are enabled on the local 228 * Bluetooth adapter. Therefore this device is both discoverable and 229 * connectable from remote Bluetooth devices. 230 */ 231 public static final int SCAN_MODE_CONNECTABLE_DISCOVERABLE = 23; 232 233 234 /** 235 * Broadcast Action: The local Bluetooth adapter has started the remote 236 * device discovery process. 237 * <p>This usually involves an inquiry scan of about 12 seconds, followed 238 * by a page scan of each new device to retrieve its Bluetooth name. 239 * <p>Register for {@link BluetoothDevice#ACTION_FOUND} to be notified as 240 * remote Bluetooth devices are found. 241 * <p>Device discovery is a heavyweight procedure. New connections to 242 * remote Bluetooth devices should not be attempted while discovery is in 243 * progress, and existing connections will experience limited bandwidth 244 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 245 * discovery. 246 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 247 */ 248 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 249 public static final String ACTION_DISCOVERY_STARTED = 250 "android.bluetooth.adapter.action.DISCOVERY_STARTED"; 251 /** 252 * Broadcast Action: The local Bluetooth adapter has finished the device 253 * discovery process. 254 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 255 */ 256 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 257 public static final String ACTION_DISCOVERY_FINISHED = 258 "android.bluetooth.adapter.action.DISCOVERY_FINISHED"; 259 260 /** 261 * Broadcast Action: The local Bluetooth adapter has changed its friendly 262 * Bluetooth name. 263 * <p>This name is visible to remote Bluetooth devices. 264 * <p>Always contains the extra field {@link #EXTRA_LOCAL_NAME} containing 265 * the name. 266 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} to receive. 267 */ 268 @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) 269 public static final String ACTION_LOCAL_NAME_CHANGED = 270 "android.bluetooth.adapter.action.LOCAL_NAME_CHANGED"; 271 /** 272 * Used as a String extra field in {@link #ACTION_LOCAL_NAME_CHANGED} 273 * intents to request the local Bluetooth name. 274 */ 275 public static final String EXTRA_LOCAL_NAME = "android.bluetooth.adapter.extra.LOCAL_NAME"; 276 277 /** @hide */ 278 public static final String BLUETOOTH_SERVICE = "bluetooth"; 279 280 private static final int ADDRESS_LENGTH = 17; 281 282 /** 283 * Lazyily initialized singleton. Guaranteed final after first object 284 * constructed. 285 */ 286 private static BluetoothAdapter sAdapter; 287 288 private final IBluetooth mService; 289 290 /** 291 * Get a handle to the default local Bluetooth adapter. 292 * <p>Currently Android only supports one Bluetooth adapter, but the API 293 * could be extended to support more. This will always return the default 294 * adapter. 295 * @return the default local adapter, or null if Bluetooth is not supported 296 * on this hardware platform 297 */ 298 public static synchronized BluetoothAdapter getDefaultAdapter() { 299 if (sAdapter == null) { 300 IBinder b = ServiceManager.getService(BluetoothAdapter.BLUETOOTH_SERVICE); 301 if (b != null) { 302 IBluetooth service = IBluetooth.Stub.asInterface(b); 303 sAdapter = new BluetoothAdapter(service); 304 } 305 } 306 return sAdapter; 307 } 308 309 /** 310 * Use {@link #getDefaultAdapter} to get the BluetoothAdapter instance. 311 * @hide 312 */ 313 public BluetoothAdapter(IBluetooth service) { 314 if (service == null) { 315 throw new IllegalArgumentException("service is null"); 316 } 317 mService = service; 318 } 319 320 /** 321 * Get a {@link BluetoothDevice} object for the given Bluetooth hardware 322 * address. 323 * <p>Valid Bluetooth hardware addresses must be upper case, in a format 324 * such as "00:11:22:33:AA:BB". The helper {@link #checkBluetoothAddress} is 325 * available to validate a Bluetooth address. 326 * <p>A {@link BluetoothDevice} will always be returned for a valid 327 * hardware address, even if this adapter has never seen that device. 328 * 329 * @param address valid Bluetooth MAC address 330 * @throws IllegalArgumentException if address is invalid 331 */ 332 public BluetoothDevice getRemoteDevice(String address) { 333 return new BluetoothDevice(address); 334 } 335 336 /** 337 * Return true if Bluetooth is currently enabled and ready for use. 338 * <p>Equivalent to: 339 * <code>getBluetoothState() == STATE_ON</code> 340 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 341 * 342 * @return true if the local adapter is turned on 343 */ 344 public boolean isEnabled() { 345 try { 346 return mService.isEnabled(); 347 } catch (RemoteException e) {Log.e(TAG, "", e);} 348 return false; 349 } 350 351 /** 352 * Get the current state of the local Bluetooth adapter. 353 * <p>Possible return values are 354 * {@link #STATE_OFF}, 355 * {@link #STATE_TURNING_ON}, 356 * {@link #STATE_ON}, 357 * {@link #STATE_TURNING_OFF}. 358 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 359 * 360 * @return current state of Bluetooth adapter 361 */ 362 public int getState() { 363 try { 364 return mService.getBluetoothState(); 365 } catch (RemoteException e) {Log.e(TAG, "", e);} 366 return STATE_OFF; 367 } 368 369 /** 370 * Turn on the local Bluetooth adapter. 371 * <p>This powers on the underlying Bluetooth hardware, and starts all 372 * Bluetooth system services. 373 * <p>This is an asynchronous call: it will return immediately, and 374 * clients should listen for {@link #ACTION_STATE_CHANGED} 375 * to be notified of subsequent adapter state changes. If this call returns 376 * true, then the adapter state will immediately transition from {@link 377 * #STATE_OFF} to {@link #STATE_TURNING_ON}, and some time 378 * later transition to either {@link #STATE_OFF} or {@link 379 * #STATE_ON}. If this call returns false then there was an 380 * immediate problem that will prevent the adapter from being turned on - 381 * such as Airplane mode, or the adapter is already turned on. 382 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 383 * 384 * @return true to indicate adapter startup has begun, or false on 385 * immediate error 386 */ 387 public boolean enable() { 388 try { 389 return mService.enable(); 390 } catch (RemoteException e) {Log.e(TAG, "", e);} 391 return false; 392 } 393 394 /** 395 * Turn off the local Bluetooth adapter. 396 * <p>This gracefully shuts down all Bluetooth connections, stops Bluetooth 397 * system services, and powers down the underlying Bluetooth hardware. 398 * <p>This is an asynchronous call: it will return immediately, and 399 * clients should listen for {@link #ACTION_STATE_CHANGED} 400 * to be notified of subsequent adapter state changes. If this call returns 401 * true, then the adapter state will immediately transition from {@link 402 * #STATE_ON} to {@link #STATE_TURNING_OFF}, and some time 403 * later transition to either {@link #STATE_OFF} or {@link 404 * #STATE_ON}. If this call returns false then there was an 405 * immediate problem that will prevent the adapter from being turned off - 406 * such as the adapter already being turned off. 407 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 408 * 409 * @return true to indicate adapter shutdown has begun, or false on 410 * immediate error 411 */ 412 public boolean disable() { 413 try { 414 return mService.disable(true); 415 } catch (RemoteException e) {Log.e(TAG, "", e);} 416 return false; 417 } 418 419 /** 420 * Returns the hardware address of the local Bluetooth adapter. 421 * <p>For example, "00:11:22:AA:BB:CC". 422 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 423 * 424 * @return Bluetooth hardware address as string 425 */ 426 public String getAddress() { 427 try { 428 return mService.getAddress(); 429 } catch (RemoteException e) {Log.e(TAG, "", e);} 430 return null; 431 } 432 433 /** 434 * Get the friendly Bluetooth name of the local Bluetooth adapter. 435 * <p>This name is visible to remote Bluetooth devices. 436 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 437 * 438 * @return the Bluetooth name, or null on error 439 */ 440 public String getName() { 441 try { 442 return mService.getName(); 443 } catch (RemoteException e) {Log.e(TAG, "", e);} 444 return null; 445 } 446 447 /** 448 * Set the friendly Bluetooth name of the local Bluetoth adapter. 449 * <p>This name is visible to remote Bluetooth devices. 450 * <p>Valid Bluetooth names are a maximum of 248 UTF-8 characters, however 451 * many remote devices can only display the first 40 characters, and some 452 * may be limited to just 20. 453 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 454 * 455 * @param name a valid Bluetooth name 456 * @return true if the name was set, false otherwise 457 */ 458 public boolean setName(String name) { 459 try { 460 return mService.setName(name); 461 } catch (RemoteException e) {Log.e(TAG, "", e);} 462 return false; 463 } 464 465 /** 466 * Get the current Bluetooth scan mode of the local Bluetooth adaper. 467 * <p>The Bluetooth scan mode determines if the local adapter is 468 * connectable and/or discoverable from remote Bluetooth devices. 469 * <p>Possible values are: 470 * {@link #SCAN_MODE_NONE}, 471 * {@link #SCAN_MODE_CONNECTABLE}, 472 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}. 473 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 474 * 475 * @return scan mode 476 */ 477 public int getScanMode() { 478 try { 479 return mService.getScanMode(); 480 } catch (RemoteException e) {Log.e(TAG, "", e);} 481 return SCAN_MODE_NONE; 482 } 483 484 /** 485 * Set the Bluetooth scan mode of the local Bluetooth adapter. 486 * <p>The Bluetooth scan mode determines if the local adapter is 487 * connectable and/or discoverable from remote Bluetooth devices. 488 * <p>For privacy reasons, discoverable mode is automatically turned off 489 * after <code>duration</code> seconds. For example, 120 seconds should be 490 * enough for a remote device to initiate and complete its discovery 491 * process. 492 * <p>Valid scan mode values are: 493 * {@link #SCAN_MODE_NONE}, 494 * {@link #SCAN_MODE_CONNECTABLE}, 495 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE}. 496 * <p>Requires {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} 497 * <p>Applications cannot set the scan mode. They should use 498 * <code>startActivityForResult( 499 * BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE}) 500 * </code>instead. 501 * 502 * @param mode valid scan mode 503 * @param duration time in seconds to apply scan mode, only used for 504 * {@link #SCAN_MODE_CONNECTABLE_DISCOVERABLE} 505 * @return true if the scan mode was set, false otherwise 506 * @hide 507 */ 508 public boolean setScanMode(int mode, int duration) { 509 try { 510 return mService.setScanMode(mode, duration); 511 } catch (RemoteException e) {Log.e(TAG, "", e);} 512 return false; 513 } 514 515 /** @hide */ 516 public boolean setScanMode(int mode) { 517 return setScanMode(mode, 120); 518 } 519 520 /** @hide */ 521 public int getDiscoverableTimeout() { 522 try { 523 return mService.getDiscoverableTimeout(); 524 } catch (RemoteException e) {Log.e(TAG, "", e);} 525 return -1; 526 } 527 528 /** @hide */ 529 public void setDiscoverableTimeout(int timeout) { 530 try { 531 mService.setDiscoverableTimeout(timeout); 532 } catch (RemoteException e) {Log.e(TAG, "", e);} 533 } 534 535 /** 536 * Start the remote device discovery process. 537 * <p>The discovery process usually involves an inquiry scan of about 12 538 * seconds, followed by a page scan of each new device to retrieve its 539 * Bluetooth name. 540 * <p>This is an asynchronous call, it will return immediately. Register 541 * for {@link #ACTION_DISCOVERY_STARTED} and {@link 542 * #ACTION_DISCOVERY_FINISHED} intents to determine exactly when the 543 * discovery starts and completes. Register for {@link 544 * BluetoothDevice#ACTION_FOUND} to be notified as remote Bluetooth devices 545 * are found. 546 * <p>Device discovery is a heavyweight procedure. New connections to 547 * remote Bluetooth devices should not be attempted while discovery is in 548 * progress, and existing connections will experience limited bandwidth 549 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 550 * discovery. 551 * <p>Device discovery will only find remote devices that are currently 552 * <i>discoverable</i> (inquiry scan enabled). Many Bluetooth devices are 553 * not discoverable by default, and need to be entered into a special mode. 554 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}. 555 * 556 * @return true on success, false on error 557 */ 558 public boolean startDiscovery() { 559 try { 560 return mService.startDiscovery(); 561 } catch (RemoteException e) {Log.e(TAG, "", e);} 562 return false; 563 } 564 565 /** 566 * Cancel the current device discovery process. 567 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}. 568 * 569 * @return true on success, false on error 570 */ 571 public boolean cancelDiscovery() { 572 try { 573 mService.cancelDiscovery(); 574 } catch (RemoteException e) {Log.e(TAG, "", e);} 575 return false; 576 } 577 578 /** 579 * Return true if the local Bluetooth adapter is currently in the device 580 * discovery process. 581 * <p>Device discovery is a heavyweight procedure. New connections to 582 * remote Bluetooth devices should not be attempted while discovery is in 583 * progress, and existing connections will experience limited bandwidth 584 * and high latency. Use {@link #cancelDiscovery()} to cancel an ongoing 585 * discovery. 586 * <p>Applications can also register for {@link #ACTION_DISCOVERY_STARTED} 587 * or {@link #ACTION_DISCOVERY_FINISHED} to be notified when discovery 588 * starts or completes. 589 * <p>Requires {@link android.Manifest.permission#BLUETOOTH}. 590 * 591 * @return true if discovering 592 */ 593 public boolean isDiscovering() { 594 try { 595 return mService.isDiscovering(); 596 } catch (RemoteException e) {Log.e(TAG, "", e);} 597 return false; 598 } 599 600 /** 601 * Return the set of {@link BluetoothDevice} objects that are bonded 602 * (paired) to the local adapter. 603 * <p>Requires {@link android.Manifest.permission#BLUETOOTH}. 604 * 605 * @return unmodifiable set of {@link BluetoothDevice}, or null on error 606 */ 607 public Set<BluetoothDevice> getBondedDevices() { 608 try { 609 return toDeviceSet(mService.listBonds()); 610 } catch (RemoteException e) {Log.e(TAG, "", e);} 611 return null; 612 } 613 614 /** 615 * Picks RFCOMM channels until none are left. 616 * Avoids reserved channels. 617 * Ideally we would pick random channels, but in the current implementation 618 * we start with the channel that is the hash of the UUID, and try every 619 * available channel from there. This means that in most cases a given 620 * uuid will use the same channel. This is a workaround for a Bluez SDP 621 * bug where we are not updating the cache when the channel changes for a 622 * uuid. 623 * TODO: Fix the Bluez SDP caching bug, and go back to random channel 624 * selection 625 */ 626 private static class RfcommChannelPicker { 627 private static final int[] RESERVED_RFCOMM_CHANNELS = new int[] { 628 10, // HFAG 629 11, // HSAG 630 12, // OPUSH 631 19, // PBAP 632 }; 633 private static LinkedList<Integer> sChannels; // master list of non-reserved channels 634 private static Random sRandom; 635 636 private final LinkedList<Integer> mChannels; // local list of channels left to try 637 638 private final UUID mUuid; 639 640 public RfcommChannelPicker(UUID uuid) { 641 synchronized (RfcommChannelPicker.class) { 642 if (sChannels == null) { 643 // lazy initialization of non-reserved rfcomm channels 644 sChannels = new LinkedList<Integer>(); 645 for (int i = 1; i <= BluetoothSocket.MAX_RFCOMM_CHANNEL; i++) { 646 sChannels.addLast(new Integer(i)); 647 } 648 for (int reserved : RESERVED_RFCOMM_CHANNELS) { 649 sChannels.remove(new Integer(reserved)); 650 } 651 sRandom = new Random(); 652 } 653 mChannels = (LinkedList<Integer>)sChannels.clone(); 654 } 655 mUuid = uuid; 656 } 657 /* Returns next channel, or -1 if we're out */ 658 public int nextChannel() { 659 int channel = mUuid.hashCode(); // always pick the same channel to try first 660 Integer channelInt; 661 while (mChannels.size() > 0) { 662 channelInt = new Integer(channel); 663 if (mChannels.remove(channelInt)) { 664 return channel; 665 } 666 channel = (channel % BluetoothSocket.MAX_RFCOMM_CHANNEL) + 1; 667 } 668 669 return -1; 670 } 671 } 672 673 /** 674 * Create a listening, secure RFCOMM Bluetooth socket. 675 * <p>A remote device connecting to this socket will be authenticated and 676 * communication on this socket will be encrypted. 677 * <p>Use {@link BluetoothServerSocket#accept} to retrieve incoming 678 * connections from a listening {@link BluetoothServerSocket}. 679 * <p>Valid RFCOMM channels are in range 1 to 30. 680 * <p>Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} 681 * @param channel RFCOMM channel to listen on 682 * @return a listening RFCOMM BluetoothServerSocket 683 * @throws IOException on error, for example Bluetooth not available, or 684 * insufficient permissions, or channel in use. 685 * @hide 686 */ 687 public BluetoothServerSocket listenUsingRfcommOn(int channel) throws IOException { 688 BluetoothServerSocket socket = new BluetoothServerSocket( 689 BluetoothSocket.TYPE_RFCOMM, true, true, channel); 690 int errno = socket.mSocket.bindListen(); 691 if (errno != 0) { 692 try { 693 socket.close(); 694 } catch (IOException e) {} 695 socket.mSocket.throwErrnoNative(errno); 696 } 697 return socket; 698 } 699 700 /** 701 * Create a listening, secure RFCOMM Bluetooth socket with Service Record. 702 * <p>A remote device connecting to this socket will be authenticated and 703 * communication on this socket will be encrypted. 704 * <p>Use {@link BluetoothServerSocket#accept} to retrieve incoming 705 * connections from a listening {@link BluetoothServerSocket}. 706 * <p>The system will assign an unused RFCOMM channel to listen on. 707 * <p>The system will also register a Service Discovery 708 * Protocol (SDP) record with the local SDP server containing the specified 709 * UUID, service name, and auto-assigned channel. Remote Bluetooth devices 710 * can use the same UUID to query our SDP server and discover which channel 711 * to connect to. This SDP record will be removed when this socket is 712 * closed, or if this application closes unexpectedly. 713 * <p>Use {@link BluetoothDevice#createRfcommSocketToServiceRecord} to 714 * connect to this socket from another device using the same {@link UUID}. 715 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} 716 * @param name service name for SDP record 717 * @param uuid uuid for SDP record 718 * @return a listening RFCOMM BluetoothServerSocket 719 * @throws IOException on error, for example Bluetooth not available, or 720 * insufficient permissions, or channel in use. 721 */ 722 public BluetoothServerSocket listenUsingRfcommWithServiceRecord(String name, UUID uuid) 723 throws IOException { 724 RfcommChannelPicker picker = new RfcommChannelPicker(uuid); 725 726 BluetoothServerSocket socket; 727 int channel; 728 int errno; 729 while (true) { 730 channel = picker.nextChannel(); 731 732 if (channel == -1) { 733 throw new IOException("No available channels"); 734 } 735 736 socket = new BluetoothServerSocket( 737 BluetoothSocket.TYPE_RFCOMM, true, true, channel); 738 errno = socket.mSocket.bindListen(); 739 if (errno == 0) { 740 if (DBG) Log.d(TAG, "listening on RFCOMM channel " + channel); 741 break; // success 742 } else if (errno == BluetoothSocket.EADDRINUSE) { 743 if (DBG) Log.d(TAG, "RFCOMM channel " + channel + " in use"); 744 try { 745 socket.close(); 746 } catch (IOException e) {} 747 continue; // try another channel 748 } else { 749 try { 750 socket.close(); 751 } catch (IOException e) {} 752 socket.mSocket.throwErrnoNative(errno); // Exception as a result of bindListen() 753 } 754 } 755 756 int handle = -1; 757 try { 758 handle = mService.addRfcommServiceRecord(name, new ParcelUuid(uuid), channel, 759 new Binder()); 760 } catch (RemoteException e) {Log.e(TAG, "", e);} 761 if (handle == -1) { 762 try { 763 socket.close(); 764 } catch (IOException e) {} 765 throw new IOException("Not able to register SDP record for " + name); 766 } 767 socket.setCloseHandler(mHandler, handle); 768 return socket; 769 } 770 771 /** 772 * Construct an unencrypted, unauthenticated, RFCOMM server socket. 773 * Call #accept to retrieve connections to this socket. 774 * @return An RFCOMM BluetoothServerSocket 775 * @throws IOException On error, for example Bluetooth not available, or 776 * insufficient permissions. 777 * @hide 778 */ 779 public BluetoothServerSocket listenUsingInsecureRfcommOn(int port) throws IOException { 780 BluetoothServerSocket socket = new BluetoothServerSocket( 781 BluetoothSocket.TYPE_RFCOMM, false, false, port); 782 int errno = socket.mSocket.bindListen(); 783 if (errno != 0) { 784 try { 785 socket.close(); 786 } catch (IOException e) {} 787 socket.mSocket.throwErrnoNative(errno); 788 } 789 return socket; 790 } 791 792 /** 793 * Construct a SCO server socket. 794 * Call #accept to retrieve connections to this socket. 795 * @return A SCO BluetoothServerSocket 796 * @throws IOException On error, for example Bluetooth not available, or 797 * insufficient permissions. 798 * @hide 799 */ 800 public static BluetoothServerSocket listenUsingScoOn() throws IOException { 801 BluetoothServerSocket socket = new BluetoothServerSocket( 802 BluetoothSocket.TYPE_SCO, false, false, -1); 803 int errno = socket.mSocket.bindListen(); 804 if (errno != 0) { 805 try { 806 socket.close(); 807 } catch (IOException e) {} 808 socket.mSocket.throwErrnoNative(errno); 809 } 810 return socket; 811 } 812 813 private Set<BluetoothDevice> toDeviceSet(String[] addresses) { 814 Set<BluetoothDevice> devices = new HashSet<BluetoothDevice>(addresses.length); 815 for (int i = 0; i < addresses.length; i++) { 816 devices.add(getRemoteDevice(addresses[i])); 817 } 818 return Collections.unmodifiableSet(devices); 819 } 820 821 private Handler mHandler = new Handler() { 822 public void handleMessage(Message msg) { 823 /* handle socket closing */ 824 int handle = msg.what; 825 try { 826 if (DBG) Log.d(TAG, "Removing service record " + Integer.toHexString(handle)); 827 mService.removeServiceRecord(handle); 828 } catch (RemoteException e) {Log.e(TAG, "", e);} 829 } 830 }; 831 832 /** 833 * Validate a Bluetooth address, such as "00:43:A8:23:10:F0" 834 * <p>Alphabetic characters must be uppercase to be valid. 835 * 836 * @param address Bluetooth address as string 837 * @return true if the address is valid, false otherwise 838 */ 839 public static boolean checkBluetoothAddress(String address) { 840 if (address == null || address.length() != ADDRESS_LENGTH) { 841 return false; 842 } 843 for (int i = 0; i < ADDRESS_LENGTH; i++) { 844 char c = address.charAt(i); 845 switch (i % 3) { 846 case 0: 847 case 1: 848 if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')) { 849 // hex character, OK 850 break; 851 } 852 return false; 853 case 2: 854 if (c == ':') { 855 break; // OK 856 } 857 return false; 858 } 859 } 860 return true; 861 } 862} 863