Java tutorial
/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.bluetooth; import android.annotation.TestApi; import android.annotation.UnsupportedAppUsage; import android.os.Build; import android.os.Parcel; import android.os.Parcelable; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.util.Arrays; /** * Represents a Bluetooth class, which describes general characteristics * and capabilities of a device. For example, a Bluetooth class will * specify the general device type such as a phone, a computer, or * headset, and whether it's capable of services such as audio or telephony. * * <p>Every Bluetooth class is composed of zero or more service classes, and * exactly one device class. The device class is further broken down into major * and minor device class components. * * <p>{@link BluetoothClass} is useful as a hint to roughly describe a device * (for example to show an icon in the UI), but does not reliably describe which * Bluetooth profiles or services are actually supported by a device. Accurate * service discovery is done through SDP requests, which are automatically * performed when creating an RFCOMM socket with {@link * BluetoothDevice#createRfcommSocketToServiceRecord} and {@link * BluetoothAdapter#listenUsingRfcommWithServiceRecord}</p> * * <p>Use {@link BluetoothDevice#getBluetoothClass} to retrieve the class for * a remote device. * * <!-- * The Bluetooth class is a 32 bit field. The format of these bits is defined at * http://www.bluetooth.org/Technical/AssignedNumbers/baseband.htm * (login required). This class contains that 32 bit field, and provides * constants and methods to determine which Service Class(es) and Device Class * are encoded in that field. * --> */ public final class BluetoothClass implements Parcelable { /** * Legacy error value. Applications should use null instead. * * @hide */ public static final int ERROR = 0xFF000000; private final int mClass; /** @hide */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) public BluetoothClass(int classInt) { mClass = classInt; } @Override public boolean equals(Object o) { if (o instanceof BluetoothClass) { return mClass == ((BluetoothClass) o).mClass; } return false; } @Override public int hashCode() { return mClass; } @Override public String toString() { return Integer.toHexString(mClass); } @Override public int describeContents() { return 0; } public static final Parcelable.Creator<BluetoothClass> CREATOR = new Parcelable.Creator<BluetoothClass>() { public BluetoothClass createFromParcel(Parcel in) { return new BluetoothClass(in.readInt()); } public BluetoothClass[] newArray(int size) { return new BluetoothClass[size]; } }; @Override public void writeToParcel(Parcel out, int flags) { out.writeInt(mClass); } /** * Defines all service class constants. * <p>Each {@link BluetoothClass} encodes zero or more service classes. */ public static final class Service { private static final int BITMASK = 0xFFE000; public static final int LIMITED_DISCOVERABILITY = 0x002000; public static final int POSITIONING = 0x010000; public static final int NETWORKING = 0x020000; public static final int RENDER = 0x040000; public static final int CAPTURE = 0x080000; public static final int OBJECT_TRANSFER = 0x100000; public static final int AUDIO = 0x200000; public static final int TELEPHONY = 0x400000; public static final int INFORMATION = 0x800000; } /** * Return true if the specified service class is supported by this * {@link BluetoothClass}. * <p>Valid service classes are the public constants in * {@link BluetoothClass.Service}. For example, {@link * BluetoothClass.Service#AUDIO}. * * @param service valid service class * @return true if the service class is supported */ public boolean hasService(int service) { return ((mClass & Service.BITMASK & service) != 0); } /** * Defines all device class constants. * <p>Each {@link BluetoothClass} encodes exactly one device class, with * major and minor components. * <p>The constants in {@link * BluetoothClass.Device} represent a combination of major and minor * device components (the complete device class). The constants in {@link * BluetoothClass.Device.Major} represent only major device classes. * <p>See {@link BluetoothClass.Service} for service class constants. */ public static class Device { private static final int BITMASK = 0x1FFC; /** * Defines all major device class constants. * <p>See {@link BluetoothClass.Device} for minor classes. */ public static class Major { private static final int BITMASK = 0x1F00; public static final int MISC = 0x0000; public static final int COMPUTER = 0x0100; public static final int PHONE = 0x0200; public static final int NETWORKING = 0x0300; public static final int AUDIO_VIDEO = 0x0400; public static final int PERIPHERAL = 0x0500; public static final int IMAGING = 0x0600; public static final int WEARABLE = 0x0700; public static final int TOY = 0x0800; public static final int HEALTH = 0x0900; public static final int UNCATEGORIZED = 0x1F00; } // Devices in the COMPUTER major class public static final int COMPUTER_UNCATEGORIZED = 0x0100; public static final int COMPUTER_DESKTOP = 0x0104; public static final int COMPUTER_SERVER = 0x0108; public static final int COMPUTER_LAPTOP = 0x010C; public static final int COMPUTER_HANDHELD_PC_PDA = 0x0110; public static final int COMPUTER_PALM_SIZE_PC_PDA = 0x0114; public static final int COMPUTER_WEARABLE = 0x0118; // Devices in the PHONE major class public static final int PHONE_UNCATEGORIZED = 0x0200; public static final int PHONE_CELLULAR = 0x0204; public static final int PHONE_CORDLESS = 0x0208; public static final int PHONE_SMART = 0x020C; public static final int PHONE_MODEM_OR_GATEWAY = 0x0210; public static final int PHONE_ISDN = 0x0214; // Minor classes for the AUDIO_VIDEO major class public static final int AUDIO_VIDEO_UNCATEGORIZED = 0x0400; public static final int AUDIO_VIDEO_WEARABLE_HEADSET = 0x0404; public static final int AUDIO_VIDEO_HANDSFREE = 0x0408; //public static final int AUDIO_VIDEO_RESERVED = 0x040C; public static final int AUDIO_VIDEO_MICROPHONE = 0x0410; public static final int AUDIO_VIDEO_LOUDSPEAKER = 0x0414; public static final int AUDIO_VIDEO_HEADPHONES = 0x0418; public static final int AUDIO_VIDEO_PORTABLE_AUDIO = 0x041C; public static final int AUDIO_VIDEO_CAR_AUDIO = 0x0420; public static final int AUDIO_VIDEO_SET_TOP_BOX = 0x0424; public static final int AUDIO_VIDEO_HIFI_AUDIO = 0x0428; public static final int AUDIO_VIDEO_VCR = 0x042C; public static final int AUDIO_VIDEO_VIDEO_CAMERA = 0x0430; public static final int AUDIO_VIDEO_CAMCORDER = 0x0434; public static final int AUDIO_VIDEO_VIDEO_MONITOR = 0x0438; public static final int AUDIO_VIDEO_VIDEO_DISPLAY_AND_LOUDSPEAKER = 0x043C; public static final int AUDIO_VIDEO_VIDEO_CONFERENCING = 0x0440; //public static final int AUDIO_VIDEO_RESERVED = 0x0444; public static final int AUDIO_VIDEO_VIDEO_GAMING_TOY = 0x0448; // Devices in the WEARABLE major class public static final int WEARABLE_UNCATEGORIZED = 0x0700; public static final int WEARABLE_WRIST_WATCH = 0x0704; public static final int WEARABLE_PAGER = 0x0708; public static final int WEARABLE_JACKET = 0x070C; public static final int WEARABLE_HELMET = 0x0710; public static final int WEARABLE_GLASSES = 0x0714; // Devices in the TOY major class public static final int TOY_UNCATEGORIZED = 0x0800; public static final int TOY_ROBOT = 0x0804; public static final int TOY_VEHICLE = 0x0808; public static final int TOY_DOLL_ACTION_FIGURE = 0x080C; public static final int TOY_CONTROLLER = 0x0810; public static final int TOY_GAME = 0x0814; // Devices in the HEALTH major class public static final int HEALTH_UNCATEGORIZED = 0x0900; public static final int HEALTH_BLOOD_PRESSURE = 0x0904; public static final int HEALTH_THERMOMETER = 0x0908; public static final int HEALTH_WEIGHING = 0x090C; public static final int HEALTH_GLUCOSE = 0x0910; public static final int HEALTH_PULSE_OXIMETER = 0x0914; public static final int HEALTH_PULSE_RATE = 0x0918; public static final int HEALTH_DATA_DISPLAY = 0x091C; // Devices in PERIPHERAL major class /** * @hide */ public static final int PERIPHERAL_NON_KEYBOARD_NON_POINTING = 0x0500; /** * @hide */ public static final int PERIPHERAL_KEYBOARD = 0x0540; /** * @hide */ public static final int PERIPHERAL_POINTING = 0x0580; /** * @hide */ public static final int PERIPHERAL_KEYBOARD_POINTING = 0x05C0; } /** * Return the major device class component of this {@link BluetoothClass}. * <p>Values returned from this function can be compared with the * public constants in {@link BluetoothClass.Device.Major} to determine * which major class is encoded in this Bluetooth class. * * @return major device class component */ public int getMajorDeviceClass() { return (mClass & Device.Major.BITMASK); } /** * Return the (major and minor) device class component of this * {@link BluetoothClass}. * <p>Values returned from this function can be compared with the * public constants in {@link BluetoothClass.Device} to determine which * device class is encoded in this Bluetooth class. * * @return device class component */ public int getDeviceClass() { return (mClass & Device.BITMASK); } /** * Return the Bluetooth Class of Device (CoD) value including the * {@link BluetoothClass.Service}, {@link BluetoothClass.Device.Major} and * minor device fields. * * <p>This value is an integer representation of Bluetooth CoD as in * Bluetooth specification. * * @see <a href="Bluetooth CoD">https://www.bluetooth.com/specifications/assigned-numbers/baseband</a> * * @hide */ @TestApi public int getClassOfDevice() { return mClass; } /** * Return the Bluetooth Class of Device (CoD) value including the * {@link BluetoothClass.Service}, {@link BluetoothClass.Device.Major} and * minor device fields. * * <p>This value is a byte array representation of Bluetooth CoD as in * Bluetooth specification. * * <p>Bluetooth COD information is 3 bytes, but stored as an int. Hence the * MSB is useless and needs to be thrown away. The lower 3 bytes are * converted into a byte array MSB to LSB. Hence, using BIG_ENDIAN. * * @see <a href="Bluetooth CoD">https://www.bluetooth.com/specifications/assigned-numbers/baseband</a> * * @hide */ public byte[] getClassOfDeviceBytes() { byte[] bytes = ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN).putInt(mClass).array(); // Discard the top byte return Arrays.copyOfRange(bytes, 1, bytes.length); } /** @hide */ @UnsupportedAppUsage public static final int PROFILE_HEADSET = 0; /** @hide */ @UnsupportedAppUsage public static final int PROFILE_A2DP = 1; /** @hide */ public static final int PROFILE_OPP = 2; /** @hide */ public static final int PROFILE_HID = 3; /** @hide */ public static final int PROFILE_PANU = 4; /** @hide */ public static final int PROFILE_NAP = 5; /** @hide */ public static final int PROFILE_A2DP_SINK = 6; /** * Check class bits for possible bluetooth profile support. * This is a simple heuristic that tries to guess if a device with the * given class bits might support specified profile. It is not accurate for all * devices. It tries to err on the side of false positives. * * @param profile The profile to be checked * @return True if this device might support specified profile. * @hide */ @UnsupportedAppUsage public boolean doesClassMatch(int profile) { if (profile == PROFILE_A2DP) { if (hasService(Service.RENDER)) { return true; } // By the A2DP spec, sinks must indicate the RENDER service. // However we found some that do not (Chordette). So lets also // match on some other class bits. switch (getDeviceClass()) { case Device.AUDIO_VIDEO_HIFI_AUDIO: case Device.AUDIO_VIDEO_HEADPHONES: case Device.AUDIO_VIDEO_LOUDSPEAKER: case Device.AUDIO_VIDEO_CAR_AUDIO: return true; default: return false; } } else if (profile == PROFILE_A2DP_SINK) { if (hasService(Service.CAPTURE)) { return true; } // By the A2DP spec, srcs must indicate the CAPTURE service. // However if some device that do not, we try to // match on some other class bits. switch (getDeviceClass()) { case Device.AUDIO_VIDEO_HIFI_AUDIO: case Device.AUDIO_VIDEO_SET_TOP_BOX: case Device.AUDIO_VIDEO_VCR: return true; default: return false; } } else if (profile == PROFILE_HEADSET) { // The render service class is required by the spec for HFP, so is a // pretty good signal if (hasService(Service.RENDER)) { return true; } // Just in case they forgot the render service class switch (getDeviceClass()) { case Device.AUDIO_VIDEO_HANDSFREE: case Device.AUDIO_VIDEO_WEARABLE_HEADSET: case Device.AUDIO_VIDEO_CAR_AUDIO: return true; default: return false; } } else if (profile == PROFILE_OPP) { if (hasService(Service.OBJECT_TRANSFER)) { return true; } switch (getDeviceClass()) { case Device.COMPUTER_UNCATEGORIZED: case Device.COMPUTER_DESKTOP: case Device.COMPUTER_SERVER: case Device.COMPUTER_LAPTOP: case Device.COMPUTER_HANDHELD_PC_PDA: case Device.COMPUTER_PALM_SIZE_PC_PDA: case Device.COMPUTER_WEARABLE: case Device.PHONE_UNCATEGORIZED: case Device.PHONE_CELLULAR: case Device.PHONE_CORDLESS: case Device.PHONE_SMART: case Device.PHONE_MODEM_OR_GATEWAY: case Device.PHONE_ISDN: return true; default: return false; } } else if (profile == PROFILE_HID) { return (getDeviceClass() & Device.Major.PERIPHERAL) == Device.Major.PERIPHERAL; } else if (profile == PROFILE_PANU || profile == PROFILE_NAP) { // No good way to distinguish between the two, based on class bits. if (hasService(Service.NETWORKING)) { return true; } return (getDeviceClass() & Device.Major.NETWORKING) == Device.Major.NETWORKING; } else { return false; } } }