android bluetoothchat 蓝牙聊天通讯

/* * Copyright (C) 2009 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 com.example.android.BluetoothChat; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.UUID; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothServerSocket; import android.bluetooth.BluetoothSocket; import android.content.Context; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.util.Log; /** * This class does all the work for setting up and managing Bluetooth * connections with other devices. It has a thread that listens for * incoming connections, a thread for connecting with a device, and a * thread for performing data transmissions when connected. */ public class BluetoothChatService { // Debugging private static final String TAG = "BluetoothChatService"; private static final boolean D = true; // Name for the SDP record when creating server socket private static final String NAME = "BluetoothChat"; // Unique UUID for this application private static final UUID MY_UUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66"); // Member fields private final BluetoothAdapter mAdapter; private final Handler mHandler; private AcceptThread mAcceptThread; private ConnectThread mConnectThread; private ConnectedThread mConnectedThread; private int mState; // Constants that indicate the current connection state public static final int STATE_NONE = 0; // we're doing nothing public static final int STATE_LISTEN = 1; // now listening for incoming connections public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection public static final int STATE_CONNECTED = 3; // now connected to a remote device /** * Constructor. Prepares a new BluetoothChat session. * @param context The UI Activity Context * @param handler A Handler to send messages back to the UI Activity */ public BluetoothChatService(Context context, Handler handler) { mAdapter = BluetoothAdapter.getDefaultAdapter(); mState = STATE_NONE; mHandler = handler; } /** * Set the current state of the chat connection * @param state An integer defining the current connection state */ private synchronized void setState(int state) { if (D) Log.d(TAG, "setState() " + mState + " -> " + state); mState = state; // Give the new state to the Handler so the UI Activity can update mHandler.obtainMessage(BluetoothChat.MESSAGE_STATE_CHANGE, state, -1).sendToTarget(); } /** * Return the current connection state. */ public synchronized int getState() { return mState; } /** * Start the chat service. Specifically start AcceptThread to begin a * session in listening (server) mode. Called by the Activity onResume() */ public synchronized void start() { if (D) Log.d(TAG, "start"); // Cancel any thread attempting to make a connection if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} // Cancel any thread currently running a connection if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} // Start the thread to listen on a BluetoothServerSocket if (mAcceptThread == null) { mAcceptThread = new AcceptThread(); mAcceptThread.start(); } setState(STATE_LISTEN); } /** * Start the ConnectThread to initiate a connection to a remote device. * @param device The BluetoothDevice to connect */ public synchronized void connect(BluetoothDevice device) { if (D) Log.d(TAG, "connect to: " + device); // Cancel any thread attempting to make a connection if (mState == STATE_CONNECTING) { if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} } // Cancel any thread currently running a connection if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} // Start the thread to connect with the given device mConnectThread = new ConnectThread(device); mConnectThread.start(); setState(STATE_CONNECTING); } /** * Start the ConnectedThread to begin managing a Bluetooth connection * @param socket The BluetoothSocket on which the connection was made * @param device The BluetoothDevice that has been connected */ public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) { if (D) Log.d(TAG, "connected"); // Cancel the thread that completed the connection if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} // Cancel any thread currently running a connection if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} // Cancel the accept thread because we only want to connect to one device if (mAcceptThread != null) {mAcceptThread.cancel(); mAcceptThread = null;} // Start the thread to manage the connection and perform transmissions mConnectedThread = new ConnectedThread(socket); mConnectedThread.start(); // Send the name of the connected device back to the UI Activity Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_DEVICE_NAME); Bundle bundle = new Bundle(); bundle.putString(BluetoothChat.DEVICE_NAME, device.getName()); msg.setData(bundle); mHandler.sendMessage(msg); setState(STATE_CONNECTED); } /** * Stop all threads */ public synchronized void stop() { if (D) Log.d(TAG, "stop"); if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} if (mAcceptThread != null) {mAcceptThread.cancel(); mAcceptThread = null;} setState(STATE_NONE); } /** * Write to the ConnectedThread in an unsynchronized manner * @param out The bytes to write * @see ConnectedThread#write(byte[]) */ public void write(byte[] out) { // Create temporary object ConnectedThread r; // Synchronize a copy of the ConnectedThread synchronized (this) { if (mState != STATE_CONNECTED) return; r = mConnectedThread; } // Perform the write unsynchronized r.write(out); } /** * Indicate that the connection attempt failed and notify the UI Activity. */ private void connectionFailed() { setState(STATE_LISTEN); // Send a failure message back to the Activity Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_TOAST); Bundle bundle = new Bundle(); bundle.putString(BluetoothChat.TOAST, "Unable to connect device"); msg.setData(bundle); mHandler.sendMessage(msg); } /** * Indicate that the connection was lost and notify the UI Activity. */ private void connectionLost() { setState(STATE_LISTEN); // Send a failure message back to the Activity Message msg = mHandler.obtainMess