BluetoothChatService.java

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/*
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 * Copyright (C) 2014 The Android Open Source Project
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 *
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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * you may not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 *      http://www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 */
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package com.example.android.bluetoothchat;
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import android.bluetooth.BluetoothAdapter;
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import android.bluetooth.BluetoothDevice;
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import android.bluetooth.BluetoothServerSocket;
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import android.bluetooth.BluetoothSocket;
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import android.content.Context;
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import android.os.Bundle;
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import android.os.Handler;
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import android.os.Message;
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import com.example.android.common.logger.Log;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.OutputStream;
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import java.util.UUID;
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/**
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 * This class does all the work for setting up and managing Bluetooth
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 * connections with other devices. It has a thread that listens for
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 * incoming connections, a thread for connecting with a device, and a
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 * thread for performing data transmissions when connected.
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 */
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public class BluetoothChatService {
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    // Debugging
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    private static final String TAG = "BluetoothChatService";
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    // Name for the SDP record when creating server socket
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    private static final String NAME_SECURE = "BluetoothChatSecure";
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    private static final String NAME_INSECURE = "BluetoothChatInsecure";
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    // Unique UUID for this application
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    private static final UUID MY_UUID_SECURE =
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            UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
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    private static final UUID MY_UUID_INSECURE =
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            UUID.fromString("8ce255c0-200a-11e0-ac64-0800200c9a66");
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    // Member fields
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    private final BluetoothAdapter mAdapter;
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    private final Handler mHandler;
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    private AcceptThread mSecureAcceptThread;
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    private AcceptThread mInsecureAcceptThread;
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    private ConnectThread mConnectThread;
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    private ConnectedThread mConnectedThread;
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    private int mState;
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    private int mNewState;
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    // Constants that indicate the current connection state
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    public static final int STATE_NONE = 0;       // we're doing nothing
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    public static final int STATE_LISTEN = 1;     // now listening for incoming connections
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    public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
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    public static final int STATE_CONNECTED = 3;  // now connected to a remote device
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    /**
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     * Constructor. Prepares a new BluetoothChat session.
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     *
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     * @param context The UI Activity Context
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     * @param handler A Handler to send messages back to the UI Activity
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     */
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    public BluetoothChatService(Context context, Handler handler) {
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        mAdapter = BluetoothAdapter.getDefaultAdapter();
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        mState = STATE_NONE;
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        mNewState = mState;
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        mHandler = handler;
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    }
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    /**
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     * Update UI title according to the current state of the chat connection
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     */
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    private synchronized void updateUserInterfaceTitle() {
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        mState = getState();
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        Log.d(TAG, "updateUserInterfaceTitle() " + mNewState + " -> " + mState);
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        mNewState = mState;
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        // Give the new state to the Handler so the UI Activity can update
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        mHandler.obtainMessage(Constants.MESSAGE_STATE_CHANGE, mNewState, -1).sendToTarget();
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    }
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    /**
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     * Return the current connection state.
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     */
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    public synchronized int getState() {
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        return mState;
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    }
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    /**
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     * Start the chat service. Specifically start AcceptThread to begin a
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     * session in listening (server) mode. Called by the Activity onResume()
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     */
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    public synchronized void start() {
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        Log.d(TAG, "start");
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        // Cancel any thread attempting to make a connection
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        if (mConnectThread != null) {
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            mConnectThread.cancel();
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            mConnectThread = null;
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        }
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        // Cancel any thread currently running a connection
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        if (mConnectedThread != null) {
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            mConnectedThread.cancel();
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            mConnectedThread = null;
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        }
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        // Start the thread to listen on a BluetoothServerSocket
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        if (mSecureAcceptThread == null) {
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            mSecureAcceptThread = new AcceptThread(true);
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            mSecureAcceptThread.start();
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        }
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        if (mInsecureAcceptThread == null) {
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            mInsecureAcceptThread = new AcceptThread(false);
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            mInsecureAcceptThread.start();
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        }
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        // Update UI title
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        updateUserInterfaceTitle();
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    }
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    /**
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     * Start the ConnectThread to initiate a connection to a remote device.
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     *
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     * @param device The BluetoothDevice to connect
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     * @param secure Socket Security type - Secure (true) , Insecure (false)
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     */
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    public synchronized void connect(BluetoothDevice device, boolean secure) {
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        Log.d(TAG, "connect to: " + device);
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        // Cancel any thread attempting to make a connection
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        if (mState == STATE_CONNECTING) {
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            if (mConnectThread != null) {
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                mConnectThread.cancel();
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                mConnectThread = null;
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            }
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        }
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        // Cancel any thread currently running a connection
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        if (mConnectedThread != null) {
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            mConnectedThread.cancel();
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            mConnectedThread = null;
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        }
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        // Start the thread to connect with the given device
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        mConnectThread = new ConnectThread(device, secure);
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        mConnectThread.start();
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        // Update UI title
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        updateUserInterfaceTitle();
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    }
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    /**
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     * Start the ConnectedThread to begin managing a Bluetooth connection
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     *
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     * @param socket The BluetoothSocket on which the connection was made
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     * @param device The BluetoothDevice that has been connected
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     */
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    public synchronized void connected(BluetoothSocket socket, BluetoothDevice
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            device, final String socketType) {
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        Log.d(TAG, "connected, Socket Type:" + socketType);
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        // Cancel the thread that completed the connection
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        if (mConnectThread != null) {
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            mConnectThread.cancel();
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            mConnectThread = null;
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        }
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        // Cancel any thread currently running a connection
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        if (mConnectedThread != null) {
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            mConnectedThread.cancel();
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            mConnectedThread = null;
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        }
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        // Cancel the accept thread because we only want to connect to one device
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        if (mSecureAcceptThread != null) {
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            mSecureAcceptThread.cancel();
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            mSecureAcceptThread = null;
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        }
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        if (mInsecureAcceptThread != null) {
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            mInsecureAcceptThread.cancel();
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            mInsecureAcceptThread = null;
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        }
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        // Start the thread to manage the connection and perform transmissions
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        mConnectedThread = new ConnectedThread(socket, socketType);
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        mConnectedThread.start();
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        // Send the name of the connected device back to the UI Activity
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        Message msg = mHandler.obtainMessage(Constants.MESSAGE_DEVICE_NAME);
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        Bundle bundle = new Bundle();
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        bundle.putString(Constants.DEVICE_NAME, device.getName());
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        msg.setData(bundle);
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        mHandler.sendMessage(msg);
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        // Update UI title
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        updateUserInterfaceTitle();
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    }
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    /**
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     * Stop all threads
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     */
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    public synchronized void stop() {
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        Log.d(TAG, "stop");
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        if (mConnectThread != null) {
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            mConnectThread.cancel();
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            mConnectThread = null;
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        }
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        if (mConnectedThread != null) {
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            mConnectedThread.cancel();
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            mConnectedThread = null;
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        }
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        if (mSecureAcceptThread != null) {
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            mSecureAcceptThread.cancel();
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            mSecureAcceptThread = null;
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        }
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        if (mInsecureAcceptThread != null) {
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            mInsecureAcceptThread.cancel();
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            mInsecureAcceptThread = null;
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        }
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        mState = STATE_NONE;
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        // Update UI title
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        updateUserInterfaceTitle();
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    }
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    /**
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     * Write to the ConnectedThread in an unsynchronized manner
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     *
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     * @param out The bytes to write
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     * @see ConnectedThread#write(byte[])
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     */
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    public void write(byte[] out) {
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        // Create temporary object
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        ConnectedThread r;
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        // Synchronize a copy of the ConnectedThread
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        synchronized (this) {
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            if (mState != STATE_CONNECTED) return;
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            r = mConnectedThread;
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        }
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        // Perform the write unsynchronized
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        r.write(out);
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    }
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    /**
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     * Indicate that the connection attempt failed and notify the UI Activity.
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     */
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    private void connectionFailed() {
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        // Send a failure message back to the Activity
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        Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
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        Bundle bundle = new Bundle();
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        bundle.putString(Constants.TOAST, "Unable to connect device");
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        msg.setData(bundle);
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        mHandler.sendMessage(msg);
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        mState = STATE_NONE;
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        // Update UI title
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        updateUserInterfaceTitle();
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        // Start the service over to restart listening mode
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        BluetoothChatService.this.start();
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    }
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    /**
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     * Indicate that the connection was lost and notify the UI Activity.
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     */
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    private void connectionLost() {
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        // Send a failure message back to the Activity
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        Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
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        Bundle bundle = new Bundle();
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        bundle.putString(Constants.TOAST, "Device connection was lost");
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        msg.setData(bundle);
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        mHandler.sendMessage(msg);
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        mState = STATE_NONE;
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        // Update UI title
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        updateUserInterfaceTitle();
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        // Start the service over to restart listening mode
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        BluetoothChatService.this.start();
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    }
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    /**
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     * This thread runs while listening for incoming connections. It behaves
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     * like a server-side client. It runs until a connection is accepted
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     * (or until cancelled).
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     */
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    private class AcceptThread extends Thread {
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        // The local server socket
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        private final BluetoothServerSocket mmServerSocket;
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        private String mSocketType;
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        public AcceptThread(boolean secure) {
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            BluetoothServerSocket tmp = null;
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            mSocketType = secure ? "Secure" : "Insecure";
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            // Create a new listening server socket
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            try {
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                if (secure) {
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                    tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE,
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                            MY_UUID_SECURE);
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                } else {
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                    tmp = mAdapter.listenUsingInsecureRfcommWithServiceRecord(
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                            NAME_INSECURE, MY_UUID_INSECURE);
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                }
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            } catch (IOException e) {
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                Log.e(TAG, "Socket Type: " + mSocketType + "listen() failed", e);
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            }
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            mmServerSocket = tmp;
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            mState = STATE_LISTEN;
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        }
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        public void run() {
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            Log.d(TAG, "Socket Type: " + mSocketType +
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                    "BEGIN mAcceptThread" + this);
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            setName("AcceptThread" + mSocketType);
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            BluetoothSocket socket = null;
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            // Listen to the server socket if we're not connected
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            while (mState != STATE_CONNECTED) {
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                try {
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                    // This is a blocking call and will only return on a
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                    // successful connection or an exception
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                    socket = mmServerSocket.accept();
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                } catch (IOException e) {
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                    Log.e(TAG, "Socket Type: " + mSocketType + "accept() failed", e);
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                    break;
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                }
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                // If a connection was accepted
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                if (socket != null) {
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                    synchronized (BluetoothChatService.this) {
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                        switch (mState) {
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                            case STATE_LISTEN:
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                            case STATE_CONNECTING:
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                                // Situation normal. Start the connected thread.
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                                connected(socket, socket.getRemoteDevice(),
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                                        mSocketType);
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                                break;
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                            case STATE_NONE:
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                            case STATE_CONNECTED:
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                                // Either not ready or already connected. Terminate new socket.
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                                try {
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                                    socket.close();
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                                } catch (IOException e) {
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                                    Log.e(TAG, "Could not close unwanted socket", e);
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                                }
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                                break;
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                        }
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                    }
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                }
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            }
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            Log.i(TAG, "END mAcceptThread, socket Type: " + mSocketType);
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        }
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        public void cancel() {
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            Log.d(TAG, "Socket Type" + mSocketType + "cancel " + this);
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            try {
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                mmServerSocket.close();
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            } catch (IOException e) {
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                Log.e(TAG, "Socket Type" + mSocketType + "close() of server failed", e);
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            }
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        }
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    }
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    /**
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     * This thread runs while attempting to make an outgoing connection
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     * with a device. It runs straight through; the connection either
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     * succeeds or fails.
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     */
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    private class ConnectThread extends Thread {
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        private final BluetoothSocket mmSocket;
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        private final BluetoothDevice mmDevice;
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        private String mSocketType;
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        public ConnectThread(BluetoothDevice device, boolean secure) {
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            mmDevice = device;
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            BluetoothSocket tmp = null;
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            mSocketType = secure ? "Secure" : "Insecure";
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            // Get a BluetoothSocket for a connection with the
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            // given BluetoothDevice
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            try {
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                if (secure) {
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                    tmp = device.createRfcommSocketToServiceRecord(
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                            MY_UUID_SECURE);
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                } else {
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                    tmp = device.createInsecureRfcommSocketToServiceRecord(
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                            MY_UUID_INSECURE);
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                }
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            } catch (IOException e) {
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                Log.e(TAG, "Socket Type: " + mSocketType + "create() failed", e);
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            }
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            mmSocket = tmp;
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            mState = STATE_CONNECTING;
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        }
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        public void run() {
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            Log.i(TAG, "BEGIN mConnectThread SocketType:" + mSocketType);
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            setName("ConnectThread" + mSocketType);
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            // Always cancel discovery because it will slow down a connection
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            mAdapter.cancelDiscovery();
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            // Make a connection to the BluetoothSocket
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            try {
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                // This is a blocking call and will only return on a
425
                // successful connection or an exception
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                mmSocket.connect();
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            } catch (IOException e) {
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                // Close the socket
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                try {
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                    mmSocket.close();
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                } catch (IOException e2) {
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                    Log.e(TAG, "unable to close() " + mSocketType +
433
                            " socket during connection failure", e2);
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                }
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                connectionFailed();
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                return;
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            }
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            // Reset the ConnectThread because we're done
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            synchronized (BluetoothChatService.this) {
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                mConnectThread = null;
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            }
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            // Start the connected thread
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            connected(mmSocket, mmDevice, mSocketType);
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        }
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        public void cancel() {
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            try {
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                mmSocket.close();
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            } catch (IOException e) {
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                Log.e(TAG, "close() of connect " + mSocketType + " socket failed", e);
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            }
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        }
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    }
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    /**
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     * This thread runs during a connection with a remote device.
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     * It handles all incoming and outgoing transmissions.
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     */
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    private class ConnectedThread extends Thread {
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        private final BluetoothSocket mmSocket;
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        private final InputStream mmInStream;
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        private final OutputStream mmOutStream;
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        public ConnectedThread(BluetoothSocket socket, String socketType) {
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            Log.d(TAG, "create ConnectedThread: " + socketType);
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            mmSocket = socket;
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            InputStream tmpIn = null;
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            OutputStream tmpOut = null;
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            // Get the BluetoothSocket input and output streams
473
            try {
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                tmpIn = socket.getInputStream();
475
                tmpOut = socket.getOutputStream();
476
            } catch (IOException e) {
477
                Log.e(TAG, "temp sockets not created", e);
478
            }
479
 
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            mmInStream = tmpIn;
481
            mmOutStream = tmpOut;
482
            mState = STATE_CONNECTED;
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        }
484
 
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        public void run() {
486
            Log.i(TAG, "BEGIN mConnectedThread");
487
            byte[] buffer = new byte[1024];
488
            int bytes;
489
 
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            // Keep listening to the InputStream while connected
491
            while (mState == STATE_CONNECTED) {
492
                try {
493
                    // Read from the InputStream
494
                    bytes = mmInStream.read(buffer);
495
 
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                    // Send the obtained bytes to the UI Activity
497
                    mHandler.obtainMessage(Constants.MESSAGE_READ, bytes, -1, buffer)
498
                            .sendToTarget();
499
                } catch (IOException e) {
500
                    Log.e(TAG, "disconnected", e);
501
                    connectionLost();
502
                    break;
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                }
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            }
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        }
506
 
507
        /**
508
         * Write to the connected OutStream.
509
         *
510
         * @param buffer The bytes to write
511
         */
512
        public void write(byte[] buffer) {
513
            try {
514
                mmOutStream.write(buffer);
515
 
516
                // Share the sent message back to the UI Activity
517
                mHandler.obtainMessage(Constants.MESSAGE_WRITE, -1, -1, buffer)
518
                        .sendToTarget();
519
            } catch (IOException e) {
520
                Log.e(TAG, "Exception during write", e);
521
            }
522
        }
523
 
524
        public void cancel() {
525
            try {
526
                mmSocket.close();
527
            } catch (IOException e) {
528
                Log.e(TAG, "close() of connect socket failed", e);
529
            }
530
        }
531
    }
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}