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.os.Handler; 20 21 import java.io.Closeable; 22 import java.io.IOException; 23 24 /** 25 * A listening Bluetooth socket. 26 * 27 * <p>The interface for Bluetooth Sockets is similar to that of TCP sockets: 28 * {@link java.net.Socket} and {@link java.net.ServerSocket}. On the server 29 * side, use a {@link BluetoothServerSocket} to create a listening server 30 * socket. When a connection is accepted by the {@link BluetoothServerSocket}, 31 * it will return a new {@link BluetoothSocket} to manage the connection. 32 * On the client side, use a single {@link BluetoothSocket} to both initiate 33 * an outgoing connection and to manage the connection. 34 * 35 * <p>The most common type of Bluetooth socket is RFCOMM, which is the type 36 * supported by the Android APIs. RFCOMM is a connection-oriented, streaming 37 * transport over Bluetooth. It is also known as the Serial Port Profile (SPP). 38 * 39 * <p>To create a listening {@link BluetoothServerSocket} that's ready for 40 * incoming connections, use 41 * {@link BluetoothAdapter#listenUsingRfcommWithServiceRecord 42 * BluetoothAdapter.listenUsingRfcommWithServiceRecord()}. Then call 43 * {@link #accept()} to listen for incoming connection requests. This call 44 * will block until a connection is established, at which point, it will return 45 * a {@link BluetoothSocket} to manage the connection. Once the {@link 46 * BluetoothSocket} is acquired, it's a good idea to call {@link #close()} on 47 * the {@link BluetoothServerSocket} when it's no longer needed for accepting 48 * connections. Closing the {@link BluetoothServerSocket} will <em>not</em> 49 * close the returned {@link BluetoothSocket}. 50 * 51 * <p>{@link BluetoothServerSocket} is thread 52 * safe. In particular, {@link #close} will always immediately abort ongoing 53 * operations and close the server socket. 54 * 55 * <p class="note"><strong>Note:</strong> 56 * Requires the {@link android.Manifest.permission#BLUETOOTH} permission. 57 * 58 * <div class="special reference"> 59 * <h3>Developer Guides</h3> 60 * <p>For more information about using Bluetooth, read the 61 * <a href="{@docRoot}guide/topics/wireless/bluetooth.html">Bluetooth</a> developer guide.</p> 62 * </div> 63 * 64 * {@see BluetoothSocket} 65 */ 66 public final class BluetoothServerSocket implements Closeable { 67 68 /*package*/ final BluetoothSocket mSocket; 69 private Handler mHandler; 70 private int mMessage; 71 private final int mChannel; 72 73 /** 74 * Construct a socket for incoming connections. 75 * @param type type of socket 76 * @param auth require the remote device to be authenticated 77 * @param encrypt require the connection to be encrypted 78 * @param port remote port 79 * @throws IOException On error, for example Bluetooth not available, or 80 * insufficient privileges 81 */ BluetoothServerSocket(int type, boolean auth, boolean encrypt, int port)82 /*package*/ BluetoothServerSocket(int type, boolean auth, boolean encrypt, int port) 83 throws IOException { 84 mChannel = port; 85 mSocket = new BluetoothSocket(type, -1, auth, encrypt, null, port, null); 86 } 87 88 /** 89 * Block until a connection is established. 90 * <p>Returns a connected {@link BluetoothSocket} on successful connection. 91 * <p>Once this call returns, it can be called again to accept subsequent 92 * incoming connections. 93 * <p>{@link #close} can be used to abort this call from another thread. 94 * @return a connected {@link BluetoothSocket} 95 * @throws IOException on error, for example this call was aborted, or 96 * timeout 97 */ accept()98 public BluetoothSocket accept() throws IOException { 99 return accept(-1); 100 } 101 102 /** 103 * Block until a connection is established, with timeout. 104 * <p>Returns a connected {@link BluetoothSocket} on successful connection. 105 * <p>Once this call returns, it can be called again to accept subsequent 106 * incoming connections. 107 * <p>{@link #close} can be used to abort this call from another thread. 108 * @return a connected {@link BluetoothSocket} 109 * @throws IOException on error, for example this call was aborted, or 110 * timeout 111 */ accept(int timeout)112 public BluetoothSocket accept(int timeout) throws IOException { 113 return mSocket.accept(timeout); 114 } 115 116 /** 117 * Immediately close this socket, and release all associated resources. 118 * <p>Causes blocked calls on this socket in other threads to immediately 119 * throw an IOException. 120 * <p>Closing the {@link BluetoothServerSocket} will <em>not</em> 121 * close any {@link BluetoothSocket} received from {@link #accept()}. 122 */ close()123 public void close() throws IOException { 124 synchronized (this) { 125 if (mHandler != null) { 126 mHandler.obtainMessage(mMessage).sendToTarget(); 127 } 128 } 129 mSocket.close(); 130 } 131 setCloseHandler(Handler handler, int message)132 /*package*/ synchronized void setCloseHandler(Handler handler, int message) { 133 mHandler = handler; 134 mMessage = message; 135 } 136 137 /** 138 * Returns the channel on which this socket is bound. 139 * @hide 140 */ getChannel()141 public int getChannel() { 142 return mChannel; 143 } 144 } 145