Java tutorial
/* * 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.notalenthack.blaster; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.Context; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.util.Log; import org.json.JSONException; import org.json.JSONObject; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.nio.ByteBuffer; import java.util.UUID; /** * 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 BluetoothSerialService { // Debugging private static final String TAG = "BluetoothReadService"; private static final boolean D = false; private static final UUID SerialPortServiceClass_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); // Member fields private final BluetoothAdapter mAdapter; private final Handler mHandler; private ConnectThread mConnectThread; private ConnectedThread mConnectedThread; private int mState; private BluetoothDevice mDevice = null; private boolean mAllowInsecureConnections; private Context mContext; // 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 BluetoothSerialService(Context context, Handler handler) { mAdapter = BluetoothAdapter.getDefaultAdapter(); mState = STATE_NONE; mHandler = handler; mContext = context; mAllowInsecureConnections = false; } /** * 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(Constants.MESSAGE_STATE_CHANGE_CMD, 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; } setState(STATE_NONE); } /** * 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); // Already connecting or connected... if (mDevice != null && mDevice.getAddress().equals(device.getAddress()) && getState() == STATE_CONNECTED) { // reset state to Connected so we get a message in the UI to // bring up our UI for set IP address setState(STATE_CONNECTED); return; } mDevice = 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; } // 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(Constants.MESSAGE_DEVICE_NAME_CMD); Bundle bundle = new Bundle(); bundle.putString(Constants.KEY_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; } 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_NONE); stop(); // stop all threads // Send a failure message back to the Activity sendMessageToast(mContext.getString(R.string.toast_unable_to_connect)); } /** * Indicate that the connection was lost and notify the UI Activity. */ private void connectionLost() { setState(STATE_NONE); stop(); // stop all threads // Send a failure message back to the Activity sendMessageToast(mContext.getString(R.string.toast_connection_lost)); } private void sendMessageToast(String msgStr) { // Send a failure message back to the Activity Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST_CMD); Bundle bundle = new Bundle(); bundle.putString(Constants.KEY_TOAST, msgStr); msg.setData(bundle); mHandler.sendMessage(msg); } private void sendMessageBackToUI(String str) { // Send a failure message back to the Activity Message msg = mHandler.obtainMessage(Constants.MESSAGE_DEVICE_SERIAL_CMD); Bundle bundle = new Bundle(); bundle.putString(Constants.KEY_JSON_STR, str); msg.setData(bundle); mHandler.sendMessage(msg); } /** * This thread runs while attempting to make an outgoing connection * with a device. It runs straight through; the connection either * succeeds or fails. */ private class ConnectThread extends Thread { private final BluetoothSocket mmSocket; private final BluetoothDevice mmDevice; public ConnectThread(BluetoothDevice device) { mmDevice = device; BluetoothSocket tmp = null; // Get a BluetoothSocket for a connection with the // given BluetoothDevice try { if (mAllowInsecureConnections) { tmp = device.createInsecureRfcommSocketToServiceRecord(SerialPortServiceClass_UUID); } else { tmp = device.createRfcommSocketToServiceRecord(SerialPortServiceClass_UUID); } } catch (Exception e) { Log.e(TAG, "create() failed", e); } mmSocket = tmp; } public void run() { Log.i(TAG, "BEGIN mConnectThread"); setName("ConnectThread"); // Always cancel discovery because it will slow down a connection mAdapter.cancelDiscovery(); // Make a connection to the BluetoothSocket try { // This is a blocking call and will only return on a // successful connection or an exception mmSocket.connect(); } catch (IOException e) { connectionFailed(); Log.e(TAG, "BtSocket Connect error " + e.getMessage(), e); // Close the socket try { mmSocket.close(); } catch (IOException e2) { Log.e(TAG, "unable to close() socket during connection failure", e2); } // Start the service over to restart listening mode //BluetoothSerialService.this.start(); return; } // Reset the ConnectThread because we're done synchronized (BluetoothSerialService.this) { mConnectThread = null; } // Start the connected thread connected(mmSocket, mmDevice); } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of connect socket failed", e); } } } /** * This thread runs during a connection with a remote device. * It handles all incoming and outgoing transmissions. */ private class ConnectedThread extends Thread { private final BluetoothSocket mmSocket; private final InputStream mmInStream; private final OutputStream mmOutStream; public ConnectedThread(BluetoothSocket socket) { Log.d(TAG, "create ConnectedThread"); mmSocket = socket; InputStream tmpIn = null; OutputStream tmpOut = null; // Get the BluetoothSocket input and output streams try { tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { Log.e(TAG, "temp sockets not created", e); } mmInStream = tmpIn; mmOutStream = tmpOut; } public void run() { Log.i(TAG, "BEGIN mConnectedThread"); byte[] buffer = new byte[1024]; int bytes; // Keep listening to the InputStream while connected while (true) { try { // Read from the InputStream bytes = mmInStream.read(buffer); byte[] in = ByteBuffer.allocate(bytes).put(buffer, 0, bytes).array(); debugInputData(in); String s = new String(in); // Share the sent message back to the UI Activity mHandler.obtainMessage(Constants.MESSAGE_READ_CMD, s.length(), -1, s).sendToTarget(); sendMessageBackToUI(s); } catch (IOException e) { Log.e(TAG, "disconnected", e); connectionLost(); break; } } } /* debug the data coming over from the device */ private void debugInputData(byte[] input) { if (D) { String inputStr = new String(input); Log.d(TAG, "read data: " + inputStr); sendMessageToast(inputStr); } } /** * Write to the connected OutStream. * @param buffer The bytes to write */ public void write(byte[] buffer) { try { mmOutStream.write(buffer); mmOutStream.flush(); // Share the sent message back to the UI Activity mHandler.obtainMessage(Constants.MESSAGE_WRITE_CMD, buffer.length, -1, buffer).sendToTarget(); } catch (IOException e) { Log.e(TAG, "Exception during write", e); sendMessageToast("Exception during write" + e); } } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of connect socket failed", e); sendMessageToast("close() of connect socket failed" + e); } } } public void setAllowInsecureConnections(boolean allowInsecureConnections) { mAllowInsecureConnections = allowInsecureConnections; } public boolean getAllowInsecureConnections() { return mAllowInsecureConnections; } /* * Format a JSON to send over the wire */ public void sendCommand(int cmd, String cmdStr, String type) { JSONObject jsonObject = new JSONObject(); try { jsonObject.put(Constants.KEY_COMMAND_TYPE, cmd); jsonObject.put(Constants.KEY_COMMAND, cmdStr); jsonObject.put(Constants.KEY_CAPTURE_OUTPUT, type); sendJSON(jsonObject); } catch (JSONException ex) { Log.e(TAG, "Bad JSON " + ex.getMessage()); sendMessageToast("Bad JSON " + ex.getMessage()); return; } } /* * Format a JSON to send over the wire */ public void sendCommand(int cmd, String cmdStr) { JSONObject jsonObject = new JSONObject(); try { jsonObject.put(Constants.KEY_COMMAND_TYPE, cmd); jsonObject.put(Constants.KEY_COMMAND, cmdStr); sendJSON(jsonObject); } catch (JSONException ex) { Log.e(TAG, "Bad JSON " + ex.getMessage()); sendMessageToast("Bad JSON " + ex.getMessage()); return; } } /* * Format a JSON to send over the wire */ public void sendCommand(int cmd, String cmdStr, int identifier) { JSONObject jsonObject = new JSONObject(); try { jsonObject.put(Constants.KEY_COMMAND_TYPE, cmd); jsonObject.put(Constants.KEY_COMMAND, cmdStr); jsonObject.put(Constants.KEY_IDENTIFIER, identifier); sendJSON(jsonObject); } catch (JSONException ex) { Log.e(TAG, "Bad JSON " + ex.getMessage()); sendMessageToast("Bad JSON " + ex.getMessage()); return; } } /* * Format a JSON to send over the wire */ public void sendStatusCommand(String cmdStr, int identifier, boolean quick) { JSONObject jsonObject = new JSONObject(); try { jsonObject.put(Constants.KEY_COMMAND_TYPE, Constants.SERIAL_CMD_STATUS); jsonObject.put(Constants.KEY_COMMAND, cmdStr); jsonObject.put(Constants.KEY_IDENTIFIER, identifier); jsonObject.put(Constants.KEY_QUICK_STATUS, quick ? 1 : 0); sendJSON(jsonObject); } catch (JSONException ex) { Log.e(TAG, "Bad JSON " + ex.getMessage()); sendMessageToast("Bad JSON " + ex.getMessage()); return; } } /* * Format a JSON to send over the wire */ public void sendCommand(int cmd) { JSONObject jsonObject = new JSONObject(); try { jsonObject.put(Constants.KEY_COMMAND_TYPE, cmd); sendJSON(jsonObject); } catch (JSONException ex) { Log.e(TAG, "Bad JSON " + ex.getMessage()); sendMessageToast("Bad JSON " + ex.getMessage()); return; } } // send the JSON over BT private void sendJSON(JSONObject jsonObject) { int len = jsonObject.toString().length(); byte[] out = ByteBuffer.allocate(len).put(jsonObject.toString().getBytes()).array(); // cmdStr if (D) { String str = new String(out); Log.d(TAG, "Send JSON: " + str); } write(out); } public void send(byte[] out) { out = Utils.handleEndOfLineChars(out); if (out.length > 0) { write(out); } } }