Develop Reference

How to connect a specific Bluetooth device and how to communicate with that device (Bluetooth chat)

I'm new in Bluetooth
I want to connect an already paired Bluetooth device and communicate with that device.
For this I use the following code.But it's not properly working
The code Finds the device but can't connect with that device.How to correct my code.
MainActivity.java
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.TextView;
import android.widget.EditText;
import android.widget.Button;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;
public class MainActivity extends Activity
{
TextView myLabel;
EditText myTextbox;
BluetoothAdapter mBluetoothAdapter;
BluetoothSocket mmSocket;
BluetoothDevice mmDevice;
OutputStream mmOutputStream;
InputStream mmInputStream;
Thread workerThread;
byte[] readBuffer;
int readBufferPosition;
int counter;
volatile boolean stopWorker;
private static final UUID MY_UUID = UUID.fromString("0000110E-0000-1000-8000-00805F9B34FB");
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button openButton = (Button)findViewById(R.id.open);
Button sendButton = (Button)findViewById(R.id.send);
Button closeButton = (Button)findViewById(R.id.close);
myLabel = (TextView)findViewById(R.id.label);
myTextbox = (EditText)findViewById(R.id.entry);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(mBluetoothAdapter == null)
{
myLabel.setText("No bluetooth adapter available");
}
if(!mBluetoothAdapter.isEnabled())
{
Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBluetooth, 0);
}
//Open Button
openButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
try
{
findBT();
openBT();
}
catch (IOException ex) { }
}
});
//Send Button
sendButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
try
{
sendData();
}
catch (IOException ex) { }
}
});
//Close button
closeButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
try
{
closeBT();
}
catch (IOException ex) { }
}
});
}
void findBT()
{
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if(pairedDevices.size() > 0)
{
for(BluetoothDevice device : pairedDevices)
{
if(device.getName().equals("BTdevice"))//name of the BT Device I want to connet
{
mmDevice = device;
myLabel.setText("Bluetooth Device Found");
break;
}
}
}
}
void openBT() throws IOException
{
mmSocket = mmDevice.createInsecureRfcommSocketToServiceRecord(MY_UUID);
mmSocket.connect();
mmOutputStream = mmSocket.getOutputStream();
mmInputStream = mmSocket.getInputStream();
beginListenForData();
myLabel.setText("Bluetooth Opened");
}
void beginListenForData()
{
final Handler handler = new Handler();
final byte delimiter = 10; //This is the ASCII code for a newline character
stopWorker = false;
readBufferPosition = 0;
readBuffer = new byte[1024];
workerThread = new Thread(new Runnable()
{
public void run()
{
while(!Thread.currentThread().isInterrupted() && !stopWorker)
{
try
{
int bytesAvailable = mmInputStream.available();
if(bytesAvailable > 0)
{
byte[] packetBytes = new byte[bytesAvailable];
mmInputStream.read(packetBytes);
for(int i=0;i<bytesAvailable;i++)
{
byte b = packetBytes[i];
if(b == delimiter)
{
byte[] encodedBytes = new byte[readBufferPosition];
System.arraycopy(readBuffer, 0, encodedBytes, 0, encodedBytes.length);
final String data = new String(encodedBytes, "US-ASCII");
readBufferPosition = 0;
handler.post(new Runnable()
{
public void run()
{
myLabel.setText(data);
}
});
}
else
{
readBuffer[readBufferPosition++] = b;
}
}
}
}
catch (IOException ex)
{
stopWorker = true;
}
}
}
});
workerThread.start();
}
void sendData() throws IOException
{
String msg = myTextbox.getText().toString();
msg += "\n";
mmOutputStream.write(msg.getBytes());
myLabel.setText("Data Sent");
}
void closeBT() throws IOException
{
stopWorker = true;
mmOutputStream.close();
mmInputStream.close();
mmSocket.close();
myLabel.setText("Bluetooth Closed");
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:ignore="TextFields,HardcodedText" >
<TextView
android:id="#+id/label"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Type here:" />
<EditText
android:id="#+id/entry"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#id/label"
android:background="#android:drawable/editbox_background" />
<Button
android:id="#+id/open"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/entry"
android:layout_alignParentRight="true"
android:layout_marginLeft="10dip"
android:layout_marginTop="48dp"
android:layout_marginRight="24dp"
android:text="Open" />
<Button
android:id="#+id/send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="#id/open"
android:layout_marginTop="7dp"
android:layout_marginRight="27dp"
android:layout_toLeftOf="#id/open"
android:text="Send" />
<Button
android:id="#+id/close"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="#id/send"
android:layout_alignParentStart="true"
android:layout_marginStart="18dp"
android:layout_marginTop="2dp"
android:text="Close"
android:layout_alignParentLeft="true"
android:layout_marginLeft="18dp" />
</RelativeLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.tosil.myapplication">
<uses-permission android:name="android.permission.BLUETOOTH"></uses-permission>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
And also I would like to Know about which Bluetooth profile is used in this code and where it is mentioned.

Android: App stop when trying to get paired bluetooth device

When trying to get the list of the paired device, unexpected error occur that make my app stops. It is new for me to solve all these complex issues.
Here is my MainActivity.java:
package com.example.admin.bluetooth_demo;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.io.IOException;
import java.util.ArrayList;
import java.util.UUID;
public class MainActivity extends AppCompatActivity {
private ListView lv;
private ArrayList<String> mDeviceList = new ArrayList<String>();
private BluetoothAdapter BA;
Button openbtn,closebtn,searchbtn,senbtn;
ArrayList<BluetoothDevice>mmPairedDevicesList;
BluetoothDevice mmDevice;
BluetoothSocket mmSocket;
EditText entry;
String msg;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv = (ListView)findViewById(R.id.list_devices);
openbtn = (Button)findViewById(R.id.button_open);
closebtn = (Button)findViewById(R.id.button_close);
searchbtn = (Button)findViewById(R.id.button_search);
senbtn = (Button)findViewById(R.id.button4);
entry = (EditText)findViewById(R.id.editText_entry);
msg = entry.getText().toString();
BA = BluetoothAdapter.getDefaultAdapter();
openbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(BA == null){
Toast.makeText(MainActivity.this,"No connection!!",Toast.LENGTH_LONG).show();
}else{
if(!BA.isEnabled()){
Intent turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnOn, 0);
Toast.makeText(getApplicationContext(), "Turned on",Toast.LENGTH_LONG).show();
}else{
Toast.makeText(getApplicationContext(), "Already on", Toast.LENGTH_LONG).show();
}
}
}
});
closebtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
BA.disable();
Toast.makeText(getApplicationContext(), "Turned off" ,Toast.LENGTH_LONG).show();
}
});
searchbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
BA.startDiscovery();
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver,filter);
}
});
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
ConnectThread mConnectThread = new ConnectThread(mmPairedDevicesList.get(position));
mConnectThread.start();
}
});
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
mDeviceList.add(device.getName() + "\n" + device.getAddress());
mmPairedDevicesList.add(device);
Log.i("BT", device.getName() + "\n" + device.getAddress());
ArrayAdapter adp = new ArrayAdapter(context,android.R.layout.simple_list_item_1,mDeviceList);
lv.setAdapter(adp);
adp.notifyDataSetChanged();
}
}
};
public class ConnectThread extends Thread{
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
public ConnectThread(BluetoothDevice device){
BluetoothSocket tmp = null;
mmDevice = device;
try{
tmp = device.createRfcommSocketToServiceRecord(uuid);
} catch (IOException e) {
e.printStackTrace();
}
mmSocket = tmp;
}
public void run(){
BA.cancelDiscovery();
try{
mmSocket.connect();
} catch (IOException e) {
try{
mmSocket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
return;
}
final ConnectedThread mConnectedThread = new ConnectedThread(mmSocket);
mConnectedThread.start();
senbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
msg += "\n";
mConnectedThread.write(msg.getBytes());
Toast.makeText(MainActivity.this,"Data sent!!!",Toast.LENGTH_LONG).show();
}
});
}
public void cancel(){
try{
mmSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Here is ConnectedThread.java:
package com.example.admin.bluetooth_demo;
import android.bluetooth.BluetoothSocket;
import android.os.Handler;
import android.os.Message;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class ConnectedThread extends Thread {
private BluetoothSocket mmBluetoothsocket;
private InputStream mInputStream;
private OutputStream mOutputStream;
public ConnectedThread(BluetoothSocket socket){
mmBluetoothsocket = socket;
InputStream tmpIN = null;
OutputStream tmpOUT = null;
try{
tmpIN = socket.getInputStream();
tmpOUT = socket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
mInputStream = tmpIN;
mOutputStream = tmpOUT;
}
public void run(){
byte[] buffer = new byte[1024];
int begin = 0;
int bytes = 0;
Handler mHandler = new Handler(){
#Override
public void handleMessage(Message msg){
byte [] writeBuff = (byte[]) msg.obj;
int begin = (int) msg.arg1;
int end = (int) msg.arg2;
switch(msg.what){
case 1:
String writeMessage = new String (writeBuff);
writeMessage = writeMessage.substring(begin,end);
break;
}
}
};
while(true){
try{
bytes += mInputStream.read(buffer, bytes, buffer.length-bytes);
for (int i = begin; i < bytes; i++){
if(buffer[i] == "#".getBytes()[0]){
mHandler.obtainMessage(1,begin,i,buffer).sendToTarget();
begin = i + 1;
if(i == bytes-1){
bytes = 0;
begin = 0;
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void write(byte[] bytes){
try{
mOutputStream.write(bytes);
} catch (IOException e) {
e.printStackTrace();
}
}
public void cancel(){
try{
mmBluetoothsocket.close();
mOutputStream.close();
mInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Here is Main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.admin.bluetooth_demo.MainActivity">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:text="Type here:"
android:ems="10"
android:layout_above="#+id/button_open"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:id="#+id/editText_entry"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/list_devices"
android:layout_above="#+id/editText_entry"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<Button
android:text="Open"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/button_open"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<Button
android:text="Close"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/button_close"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#+id/button_open"
android:layout_toEndOf="#+id/button_open" />
<Button
android:text="Send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/button4"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#+id/button_close"
android:layout_toEndOf="#+id/button_close" />
<Button
android:text="Search"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/button_search"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
</RelativeLayout>

Calling a method from another class in broadcast receiver

I'm working on a project which consists of two classes. The first, MainActivity.java, deals with sending a single char over a bluetooth connection. The second, SmsReceiver.java, is a broadcast reciver for detecting incoming sms messages. When SmsReceiver.java detects an incoming message it should call the method turnLedOn, which resides in the bluetooth class.
I've tested both of them and they work. Then I tried connecting them by calling MainActivity.turnLedOn(context); in the onReceive method of the broadcast receiver, but it didn't work.
Does anybody know why and what should be done to remedy this? Below is the code of the whole project.
Thank you in advance.
MainActivity.java
package com.example.bluetooth;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
//You first have to connect with your android phone to the arduino bt module.
BluetoothAdapter mBluetoothAdapter = null;
ConnectThread mConnectThread = null;
BluetoothDevice mDevice = null;
public static ConnectedThread mConnectedThread = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button button = (Button) findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mConnectedThread.write("1".getBytes());
}
});
final Button button2 = (Button) findViewById(R.id.button2);
button2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mConnectedThread.write("0".getBytes());
}
});
BluetoothDevice mDevice = null;
//Check if phone supports bluetooth
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
// Device does not support Bluetooth
}
Toast.makeText(this, "BT supported", Toast.LENGTH_SHORT).show();
Log.e("BLUETOOTH", "BT supported");
// Check if bluetooth is enabled. If not, enable it.
if (!mBluetoothAdapter.isEnabled()) {
Toast.makeText(this, "BT disabled", Toast.LENGTH_SHORT).show();
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
}
Toast.makeText(this, "BT enabled", Toast.LENGTH_SHORT).show();
Log.e("BLUETOOTH", "BT enabled");
// Chech which device we connected with, at the beginning
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
Toast.makeText(this, "Paired with a BT device", Toast.LENGTH_SHORT).show();
Log.e("BLUETOOTH", "paired with a BT device");
for (BluetoothDevice device : pairedDevices) {
Toast.makeText(this, device.getName() + " " + device.getAddress(), Toast.LENGTH_SHORT).show();
mDevice = device;
}
}
// Source 7 - Creating the connection thread
mConnectThread = new ConnectThread(mDevice);
mConnectThread.start();
}
public static void turnLedOn(Context context){
mConnectedThread.write("1".getBytes());
}
public static void turnLedOff(Context context){
mConnectedThread.write("0".getBytes());
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
//Thread which creates a connection between arduino and phone
private class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
private final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
public ConnectThread(BluetoothDevice device) {
BluetoothSocket tmp = null;
mmDevice = device;
try {
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) { }
mmSocket = tmp;
}
public void run() {
mBluetoothAdapter.cancelDiscovery();
try {
mmSocket.connect();
} catch (IOException connectException) {
try {
mmSocket.close();
} catch (IOException closeException) { }
return;
}
//Source 10 - create the data transfer thread
//Manage connection
mConnectedThread = new ConnectedThread(mmSocket);
mConnectedThread.start();
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
// end of connection thread
//Thread for sending and receiving messages
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[1024];
int begin = 0;
int bytes = 0;
while (true) {
try {
bytes += mmInStream.read(buffer, bytes, buffer.length
- bytes);
for (int i = begin; i < bytes; i++) {
if (buffer[i] == "#".getBytes()[0]) {
mHandler.obtainMessage(1, begin, i, buffer)
.sendToTarget();
begin = i + 1;
if (i == bytes - 1) {
bytes = 0;
begin = 0;
}
}
}
} catch (IOException e) {
break;
}
}
}
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) {
}
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
}
//End of thread for sending and receiving
//Source 9 - handler for sending
Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
byte[] writeBuf = (byte[]) msg.obj;
int begin = (int) msg.arg1;
int end = (int) msg.arg2;
switch (msg.what) {
case 1:
String writeMessage = new String(writeBuf);
writeMessage = writeMessage.substring(begin, end);
break;
}
}
};
}
SmsReceiver.java
package com.example.bluetooth;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.widget.Toast;
public class SmsReceiver extends BroadcastReceiver
{
#Override
public void onReceive(Context context, Intent intent)
{
//---get the SMS message passed in---
Bundle bundle = intent.getExtras();
SmsMessage[] msgs = null;
String messageReceived = "";
if (bundle != null)
{
//---retrieve the SMS message received---
Object[] pdus = (Object[]) bundle.get("pdus");
msgs = new SmsMessage[pdus.length];
for (int i=0; i<msgs.length; i++)
{
msgs[i] = SmsMessage.createFromPdu((byte[])pdus[i]);
messageReceived += msgs[i].getMessageBody().toString();
messageReceived += "\n";
}
//---display the new SMS message---
Toast.makeText(context, messageReceived, Toast.LENGTH_SHORT).show();
MainActivity.turnLedOn(context);
// Get the Sender Phone Number
String senderPhoneNumber=msgs[0].getOriginatingAddress ();
}
}
}
MainActivity layout
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
<Button
android:id="#+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/textView1"
android:layout_below="#+id/textView1"
android:layout_marginTop="34dp"
android:text="On" />
<Button
android:id="#+id/button2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/button1"
android:layout_below="#+id/button1"
android:layout_marginTop="68dp"
android:text="Off" />
</RelativeLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.bluetooth"
android:versionCode="1"
android:versionName="1.0" >
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<receiver android:name=".SmsReceiver">
<intent-filter>
<action android:name=
"android.provider.Telephony.SMS_RECEIVED" />
</intent-filter>
</receiver>
<activity
android:name="com.example.bluetooth.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.RECEIVE_SMS"></uses-permission>
</manifest>
Edit: Registered the broadcast receiver in the manifest as #donison24x7 suggested.
Edit2: Sorry about this. Also added the RECEIVE_SMS permission in the manifest. It works now.

You havn't registered the Broadcast receiver 'SmsReceiver.java' in manifest.
Register it like this.....
<receiver
android:name=".SmsReceiver" >
<intent-filter>
<action android:name="your.Action.name" />
</intent-filter>
</receiver>

One possible solution is to use LocalBroadcastManager to communicate between your receiver class and your activity class:
Fire up an Intent in your receiver class in onReceive() with:
Intent i = new Intent("NameYourIntentHere");
LocalBroadcastManager.getInstance(context).sendBroadcast(i);
Get the LocalBroadcast intent in your Activity class:
private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Do your stuff here
}
};
And register your LocalBroadcast receiver in your activity class so it gets notified:
#Override
protected void onPause() {
super.onPause();
LocalBroadcastManager.getInstance(this).unregisterReceiver(mBroadcastReceiver);
}
#Override
protected void onResume() {
super.onResume();
LocalBroadcastManager.getInstance(this).registerReceiver(mBroadcastReceiver,
new IntentFilter("NameYourIntentHere"));
}

How to connect a mobile and a printer via bluetooth in android?

Can anyone tell me how to connect a mobile and a printer via bluetooth to print a text file in android?
That is,if i click the print button from the android application,the printer has to print that corresponding file.As per my knowledge i have searched for it in Google, but i couldn't find any good samples to do it.Has anyone have at-least one sample android program to do this, it will be better to clear my chaos.
Suggestions please.
Thanks for your precious time!..

Bluetooth Printer Android Example
Create a new android project BlueToothPrinterApp in your editor.
Step 1:
Create main activity like below
com.example.BlueToothPrinterApp / BlueToothPrinterApp.java
package com.example.BlueToothPrinterApp;
import android.app.Activity;
import android.os.Bundle;
import java.io.IOException;
import java.io.OutputStream;
import android.bluetooth.BluetoothSocket;
import android.content.ContentValues;
import android.content.Intent;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class BlueToothPrinterApp extends Activity {
/** Called when the activity is first created. */
EditText message;
Button printbtn;
byte FONT_TYPE;
private static BluetoothSocket btsocket;
private static OutputStream btoutputstream;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
message = (EditText) findViewById(R.id.message);
printbtn = (Button) findViewById(R.id.printButton);
printbtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
connect();
}
});
}
protected void connect() {
if (btsocket == null) {
Intent BTIntent = new Intent(getApplicationContext(), BTDeviceList.class);
this.startActivityForResult(BTIntent, BTDeviceList.REQUEST_CONNECT_BT);
} else {
OutputStream opstream = null;
try {
opstream = btsocket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
btoutputstream = opstream;
print_bt();
}
}
private void print_bt() {
try {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
btoutputstream = btsocket.getOutputStream();
byte[] printformat = {
0x1B,
0× 21,
FONT_TYPE
};
btoutputstream.write(printformat);
String msg = message.getText().toString();
btoutputstream.write(msg.getBytes());
btoutputstream.write(0x0D);
btoutputstream.write(0x0D);
btoutputstream.write(0x0D);
btoutputstream.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void onDestroy() {
super.onDestroy();
try {
if (btsocket != null) {
btoutputstream.close();
btsocket.close();
btsocket = null;
}
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
try {
btsocket = BTDeviceList.getSocket();
if (btsocket != null) {
print_bt();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
Step 2:
com.example.BlueToothPrinterApp / BTDeviceList.java
package com.example.BlueToothPrinterApp;
import java.io.IOException;
import java.util.Set;
import java.util.UUID;
import android.app.ListActivity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class BTDeviceList extends ListActivity {
static public final int REQUEST_CONNECT_BT = 0× 2300;
static private final int REQUEST_ENABLE_BT = 0× 1000;
static private BluetoothAdapter mBluetoothAdapter = null;
static private ArrayAdapter < String > mArrayAdapter = null;
static private ArrayAdapter < BluetoothDevice > btDevices = null;
private static final UUID SPP_UUID = UUID
.fromString(“8 ce255c0 - 200 a - 11e0 - ac64 - 0800200 c9a66″);
// UUID.fromString(“00001101-0000-1000-8000-00805F9B34FB”);
static private BluetoothSocket mbtSocket = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle(“Bluetooth Devices”);
try {
if (initDevicesList() != 0) {
this.finish();
return;
}
} catch (Exception ex) {
this.finish();
return;
}
IntentFilter btIntentFilter = new IntentFilter(
BluetoothDevice.ACTION_FOUND);
registerReceiver(mBTReceiver, btIntentFilter);
}
public static BluetoothSocket getSocket() {
return mbtSocket;
}
private void flushData() {
try {
if (mbtSocket != null) {
mbtSocket.close();
mbtSocket = null;
}
if (mBluetoothAdapter != null) {
mBluetoothAdapter.cancelDiscovery();
}
if (btDevices != null) {
btDevices.clear();
btDevices = null;
}
if (mArrayAdapter != null) {
mArrayAdapter.clear();
mArrayAdapter.notifyDataSetChanged();
mArrayAdapter.notifyDataSetInvalidated();
mArrayAdapter = null;
}
finalize();
} catch (Exception ex) {} catch (Throwable e) {}
}
private int initDevicesList() {
flushData();
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
Toast.makeText(getApplicationContext(), “Bluetooth not supported!!”, Toast.LENGTH_LONG).show();
return -1;
}
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
mArrayAdapter = new ArrayAdapter < String > (getApplicationContext(),
android.R.layout.simple_list_item_1);
setListAdapter(mArrayAdapter);
Intent enableBtIntent = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
try {
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} catch (Exception ex) {
return -2;
}
Toast.makeText(getApplicationContext(), “Getting all available Bluetooth Devices”, Toast.LENGTH_SHORT)
.show();
return 0;
}
#Override
protected void onActivityResult(int reqCode, int resultCode, Intent intent) {
super.onActivityResult(reqCode, resultCode, intent);
switch (reqCode) {
case REQUEST_ENABLE_BT:
if (resultCode == RESULT_OK) {
Set < BluetoothDevice > btDeviceList = mBluetoothAdapter
.getBondedDevices();
try {
if (btDeviceList.size() > 0) {
for (BluetoothDevice device: btDeviceList) {
if (btDeviceList.contains(device) == false) {
btDevices.add(device);
mArrayAdapter.add(device.getName() + “\n” +
device.getAddress());
mArrayAdapter.notifyDataSetInvalidated();
}
}
}
} catch (Exception ex) {}
}
break;
}
mBluetoothAdapter.startDiscovery();
}
private final BroadcastReceiver mBTReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
try {
if (btDevices == null) {
btDevices = new ArrayAdapter < BluetoothDevice > (
getApplicationContext(), android.R.id.text1);
}
if (btDevices.getPosition(device) < 0) {
btDevices.add(device);
mArrayAdapter.add(device.getName() + “\n” +
device.getAddress() + “\n”);
mArrayAdapter.notifyDataSetInvalidated();
}
} catch (Exception ex) {
// ex.fillInStackTrace();
}
}
}
};
#Override
protected void onListItemClick(ListView l, View v, final int position,
long id) {
super.onListItemClick(l, v, position, id);
if (mBluetoothAdapter == null) {
return;
}
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
Toast.makeText(
getApplicationContext(), “Connecting to” + btDevices.getItem(position).getName() + “, ”
+btDevices.getItem(position).getAddress(),
Toast.LENGTH_SHORT).show();
Thread connectThread = new Thread(new Runnable() {
#Override
public void run() {
try {
boolean gotuuid = btDevices.getItem(position)
.fetchUuidsWithSdp();
UUID uuid = btDevices.getItem(position).getUuids()[0]
.getUuid();
mbtSocket = btDevices.getItem(position)
.createRfcommSocketToServiceRecord(uuid);
mbtSocket.connect();
} catch (IOException ex) {
runOnUiThread(socketErrorRunnable);
try {
mbtSocket.close();
} catch (IOException e) {
// e.printStackTrace();
}
mbtSocket = null;
return;
} finally {
runOnUiThread(new Runnable() {
#Override
public void run() {
finish();
}
});
}
}
});
connectThread.start();
}
private Runnable socketErrorRunnable = new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(), “Cannot establish connection”, Toast.LENGTH_SHORT).show();
mBluetoothAdapter.startDiscovery();
}
};
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, Menu.FIRST, Menu.NONE, “Refresh Scanning”);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
switch (item.getItemId()) {
case Menu.FIRST:
initDevicesList();
break;
}
return true;
}
}
Step 3:
Edit your main.xml file and paste below code.
res/layout/main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingLeft="16dp"
android:paddingRight="16dp">
<TextView
android:id="#+id/msgtextlbl"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Enter Your Message : "/>
<EditText
android:id="#+id/message"
android:layout_width="fill_parent"
android:layout_height="100dp"
android:layout_below="#+id/msgtextlbl"
android:text=""/>
<Button
android:id="#+id/printButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/message"
android:layout_centerHorizontal="true"
android:layout_marginTop="5dip"
android:text="Print"/>
</RelativeLayout>
Step 4:
Now edit your AndroidManifest.xml
Add bluetooth permission and admin permission.
AndroidManifest.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<manifest
xmlns:android=”http://schemas.android.com/apk/res/android
package=”com.example.BlueToothPrinterApp”
android:versionCode=”1″
android:versionName=”1.0″>
<uses-sdk android:minSdkVersion=”14″ />
<uses-permission android:name=”android.permission.BLUETOOTH”></uses-permission>
<uses-permission android:name=”android.permission.BLUETOOTH_ADMIN”></uses-permission>
<application
android:label=”#string/app_name”
android:icon=”#drawable/ic_launcher”>
<activity
android:name=”BlueToothPrinterApp”
android:label=”#string/app_name”>
<intent-filter>
<action android:name=”android.intent.action.MAIN” />
<category android:name=”android.intent.category.LAUNCHER” />
</intent-filter>
</activity>
<activity android:name=”BTDeviceList”></activity>
</application>
</manifest>
Compile and run this application. Enter message and press print button.
You will see list of bluetooth devices. Select bluettoth printer.
Check print on your bluetooth printer.
here is the CODE Reference...

You can use this awesome lib, you can connect to any printer and print easily,
https://github.com/mazenrashed/Printooth
you can download it by:
implementation 'com.github.mazenrashed:Printooth:${LAST_VERSION}'
and use it like:
var printables = ArrayList<Printable>()
var printable = Printable.PrintableBuilder()
.setText("Hello World")
printables.add(printable)
BluetoothPrinter.printer().print(printables)

Android how to call a method of MainActivity in SmsReceiver Class

I'm very new to Android Programming, It would be really great if someone can help me in this.My project contains two JAVA files.
MainActivity.java extends Activity
SMSReceiver.java extends Broadcastreceiver
The SMSreceiver.java has the code which displays any incoming SMS in toast. Can you please tell me how to call a function in MainActivity whenever a particular SMS is received. For eg: when I receive sms called as starttemp it should call a function starttemp.
I have searched a lot and found that intents are a way to do this and we cannot call these methods directly. Please can anyone help me in this? And it would be really great if someone can send me working code.
This would be my MainACtivity.Java
package com.wissen.sms;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;
import android.widget.EditText;
import android.widget.Button;
import android.widget.ToggleButton;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;
#SuppressLint({ "NewApi", "NewApi", "NewApi", "NewApi", "NewApi", "NewApi", "NewApi", "NewApi", "NewApi", "NewApi" }) public class MainActivity extends Activity
{
TextView myLabel;
EditText myTextbox;
ToggleButton switch1;
BluetoothAdapter mBluetoothAdapter;
BluetoothSocket mmSocket;
BluetoothDevice mmDevice;
OutputStream mmOutputStream;
InputStream mmInputStream;
Thread workerThread;
byte[] readBuffer;
int readBufferPosition;
int counter;
String status;
volatile boolean stopWorker;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button openButton = (Button)findViewById(R.id.open);
Button sendButton = (Button)findViewById(R.id.send);
Button closeButton = (Button)findViewById(R.id.close);
myLabel = (TextView)findViewById(R.id.label);
myTextbox = (EditText)findViewById(R.id.entry);
//switch1
switch1 = (ToggleButton) findViewById(R.id.switch1);
switch1.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
if(switch1.isChecked()){
try
{
String msg = "01ON";
msg += "\n\r";
mmOutputStream.write(msg.getBytes());
myLabel.setText("Data Sent");
}
catch (IOException ex) { }
}else{
try
{
String msg = "01OF";
msg += "\n\r";
mmOutputStream.write(msg.getBytes());
myLabel.setText("Data Sent");
}
catch (IOException ex) { }
}
}
});
//Open Button
openButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
try
{
findBT();
openBT();
}
catch (IOException ex) { }
}
});
//Send Button
sendButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
try
{
sendData();
}
catch (IOException ex) { }
}
});
//Close button
closeButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
try
{
closeBT();
}
catch (IOException ex) { }
}
});
}
void findBT()
{
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(mBluetoothAdapter == null)
{
myLabel.setText("No bluetooth adapter available");
}
if(!mBluetoothAdapter.isEnabled())
{
Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBluetooth, 0);
}
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if(pairedDevices.size() > 0)
{
for(BluetoothDevice device : pairedDevices)
{
if(device.getName().equals("HomeAutomation"))
{
mmDevice = device;
break;
}
}
}
myLabel.setText("Bluetooth Device Found");
}
void openBT() throws IOException
{
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"); //Standard SerialPortService ID
mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
mmSocket.connect();
mmOutputStream = mmSocket.getOutputStream();
mmInputStream = mmSocket.getInputStream();
beginListenForData();
myLabel.setText("Bluetooth Opened");
}
void beginListenForData()
{
final Handler handler = new Handler();
final byte delimiter = 10; //This is the ASCII code for a newline character
stopWorker = false;
readBufferPosition = 0;
readBuffer = new byte[1024];
workerThread = new Thread(new Runnable()
{
public void run()
{
while(!Thread.currentThread().isInterrupted() && !stopWorker)
{
try
{
int bytesAvailable = mmInputStream.available();
if(bytesAvailable > 0)
{
byte[] packetBytes = new byte[bytesAvailable];
mmInputStream.read(packetBytes);
for(int i=0;i<bytesAvailable;i++)
{
byte b = packetBytes[i];
if(b == delimiter)
{
byte[] encodedBytes = new byte[readBufferPosition];
System.arraycopy(readBuffer, 0, encodedBytes, 0, encodedBytes.length);
final String data = new String(encodedBytes, "US-ASCII");
readBufferPosition = 0;
handler.post(new Runnable()
{
public void run()
{
status=data;
myLabel.setText(data);
}
});
}
else
{
readBuffer[readBufferPosition++] = b;
}
}
}
}
catch (IOException ex)
{
stopWorker = true;
}
}
}
});
workerThread.start();
}
void sendData() throws IOException
{
String msg = myTextbox.getText().toString();
msg += "\n\r";
mmOutputStream.write(msg.getBytes());
myLabel.setText("Data Sent");
}
void closeBT() throws IOException
{
stopWorker = true;
mmOutputStream.close();
mmInputStream.close();
mmSocket.close();
myLabel.setText("Bluetooth Closed");
}
}
This would be My SMSReceiver.Java
package com.wissen.sms.receiver;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.gsm.SmsMessage;
import android.widget.Toast;
public class SMSReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Bundle bundle = intent.getExtras();
Object messages[] = (Object[]) bundle.get("pdus");
SmsMessage smsMessage[] = new SmsMessage[messages.length];
for (int n = 0; n < messages.length; n++) {
smsMessage[n] = SmsMessage.createFromPdu((byte[]) messages[n]);
}
Toast toast = Toast.makeText(context, "Received SMS: " + smsMessage[0].getMessageBody(), Toast.LENGTH_LONG);
toast.show();
}
}
Now i want to call a method of MainActivity.java whenever a new message is received
void somemethod()
{
try
{
String msg = "01ON";
msg += "\n\r";
mmOutputStream.write(msg.getBytes());
myLabel.setText("Data Sent");
}
catch (IOException ex) { }
}
}

One best way for use MainActivity method from Broadcast receiver class is
Define your method as a static and than you can use that method using below code
Activityname.methodname()
I tried this and its worked fine for me.
for example
public class SMSBroadcastReceiver extends BroadcastReceiver {
private static final String SMS_RECEIVED = "android.provider.Telephony.SMS_RECEIVED";
private static final String TAG = "SMSBroadcastReceiver";
#Override
public void onReceive(Context context, Intent intent) {
Log.i(TAG, "Intent recieved: " + intent.getAction());
if (intent.getAction() == SMS_RECEIVED) {
Bundle bundle = intent.getExtras();
if (bundle != null) {
Object[] pdus = (Object[])bundle.get("pdus");
abc.methodtocall();
}
}
}
}
and your Activity code like this
public class abc extends Activity{
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public static void methodtocall(){
//Your code here...
}
}