The previous post show how to
List paired BlueTooth devices. Here I show how to make connection between Android devices with Bluetooth.
In order to make it simple, I separate its functionality in two app:
- AndroidBlueToothBeCOnnected:
It start a BluetoothServerSocket by calling bluetoothAdapter.listenUsingRfcommWithServiceRecord().
Then wait for connection with accept(). - AndroidBlueTooth:
It search for paired bluetooth devices, and request connect.
This example show making connection only, nothing else can do.
AndroidBlueToothBeCOnnected:MainActivity.java
package com.example.androidbluetoothbeconnected;
import java.io.IOException;
import java.util.UUID;
import android.support.v7.app.ActionBarActivity;
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.content.pm.PackageManager;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
private static final int REQUEST_ENABLE_BT = 1;
BluetoothAdapter bluetoothAdapter;
private UUID myUUID;
private String myName;
TextView textInfo, textStatus;
ThreadBeConnected myThreadBeConnected;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textInfo = (TextView)findViewById(R.id.info);
textStatus = (TextView)findViewById(R.id.status);
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)){
Toast.makeText(this,
"FEATURE_BLUETOOTH NOT support",
Toast.LENGTH_LONG).show();
finish();
return;
}
//generate UUID on web: http://www.famkruithof.net/uuid/uuidgen
//have to match the UUID on the another device of the BT connection
myUUID = UUID.fromString("ec79da00-853f-11e4-b4a9-0800200c9a66");
myName = myUUID.toString();
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter == null) {
Toast.makeText(this,
"Bluetooth is not supported on this hardware platform",
Toast.LENGTH_LONG).show();
finish();
return;
}
String stInfo = bluetoothAdapter.getName() + "\n" +
bluetoothAdapter.getAddress();
textInfo.setText(stInfo);
}
@Override
protected void onStart() {
super.onStart();
//Turn ON BlueTooth if it is OFF
if (!bluetoothAdapter.isEnabled()) {
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}
setup();
}
private void setup() {
textStatus.setText("setup()");
myThreadBeConnected = new ThreadBeConnected();
myThreadBeConnected.start();
}
@Override
protected void onDestroy() {
super.onDestroy();
if(myThreadBeConnected!=null){
myThreadBeConnected.cancel();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode==REQUEST_ENABLE_BT){
if(resultCode == Activity.RESULT_OK){
setup();
}else{
Toast.makeText(this,
"BlueTooth NOT enabled",
Toast.LENGTH_SHORT).show();
finish();
}
}
}
private class ThreadBeConnected extends Thread {
private BluetoothServerSocket bluetoothServerSocket = null;
public ThreadBeConnected() {
try {
bluetoothServerSocket =
bluetoothAdapter.listenUsingRfcommWithServiceRecord(myName, myUUID);
textStatus.setText("Waiting\n"
+ "bluetoothServerSocket :\n"
+ bluetoothServerSocket);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void run() {
BluetoothSocket bluetoothSocket = null;
if(bluetoothServerSocket!=null){
try {
bluetoothSocket = bluetoothServerSocket.accept();
BluetoothDevice remoteDevice = bluetoothSocket.getRemoteDevice();
final String strConnected = "Connected:\n" +
remoteDevice.getName() + "\n" +
remoteDevice.getAddress();
//connected
runOnUiThread(new Runnable(){
@Override
public void run() {
textStatus.setText(strConnected);
}});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
final String eMessage = e.getMessage();
runOnUiThread(new Runnable(){
@Override
public void run() {
textStatus.setText("something wrong: \n" + eMessage);
}});
}
}else{
runOnUiThread(new Runnable(){
@Override
public void run() {
textStatus.setText("bluetoothServerSocket == null");
}});
}
}
public void cancel() {
Toast.makeText(getApplicationContext(),
"close bluetoothServerSocket",
Toast.LENGTH_LONG).show();
try {
bluetoothServerSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
/res/layout/activity_main.xml
<LinearLayout 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"
android:orientation="vertical"
tools:context="com.example.androidbluetoothbeconnected.MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:autoLink="web"
android:text="http://android-er.blogspot.com/"
android:textStyle="bold" />
<TextView
android:id="@+id/info"
android:textStyle="bold|italic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/status"
android:textSize="28sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
Modify AndroidManifest.xml to add permission of "android.permission.BLUETOOTH".
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.androidbluetoothbeconnected"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.BLUETOOTH"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".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>
</manifest>
Download the files.
AndroidBlueTooth:MainActivity.java
package com.example.androidbluetooth;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;
import android.support.v7.app.ActionBarActivity;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity {
private static final int REQUEST_ENABLE_BT = 1;
BluetoothAdapter bluetoothAdapter;
ArrayList<BluetoothDevice> pairedDeviceArrayList;
TextView textInfo, textStatus;
ListView listViewPairedDevice;
ArrayAdapter<BluetoothDevice> pairedDeviceAdapter;
private UUID myUUID;
ThreadConnectBTdevice myThreadConnectBTdevice;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textInfo = (TextView)findViewById(R.id.info);
textStatus = (TextView)findViewById(R.id.status);
listViewPairedDevice = (ListView)findViewById(R.id.pairedlist);
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)){
Toast.makeText(this,
"FEATURE_BLUETOOTH NOT support",
Toast.LENGTH_LONG).show();
finish();
return;
}
//generate UUID on web: http://www.famkruithof.net/uuid/uuidgen
//have to match the UUID on the another device of the BT connection
myUUID = UUID.fromString("ec79da00-853f-11e4-b4a9-0800200c9a66");
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter == null) {
Toast.makeText(this,
"Bluetooth is not supported on this hardware platform",
Toast.LENGTH_LONG).show();
finish();
return;
}
String stInfo = bluetoothAdapter.getName() + "\n" +
bluetoothAdapter.getAddress();
textInfo.setText(stInfo);
}
@Override
protected void onStart() {
super.onStart();
//Turn ON BlueTooth if it is OFF
if (!bluetoothAdapter.isEnabled()) {
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}
setup();
}
private void setup() {
Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
pairedDeviceArrayList = new ArrayList<BluetoothDevice>();
for (BluetoothDevice device : pairedDevices) {
pairedDeviceArrayList.add(device);
}
pairedDeviceAdapter = new ArrayAdapter<BluetoothDevice>(this,
android.R.layout.simple_list_item_1, pairedDeviceArrayList);
listViewPairedDevice.setAdapter(pairedDeviceAdapter);
listViewPairedDevice.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
BluetoothDevice device =
(BluetoothDevice)parent.getItemAtPosition(position);
Toast.makeText(MainActivity.this,
"Name: " + device.getName() + "\n"
+ "Address: " + device.getAddress() + "\n"
+ "BondState: " + device.getBondState() + "\n"
+ "BluetoothClass: " + device.getBluetoothClass() + "\n"
+ "Class: " + device.getClass(),
Toast.LENGTH_LONG).show();
textStatus.setText("start ThreadConnectBTdevice");
myThreadConnectBTdevice = new ThreadConnectBTdevice(device);
myThreadConnectBTdevice.start();
}});
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if(myThreadConnectBTdevice!=null){
myThreadConnectBTdevice.cancel();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode==REQUEST_ENABLE_BT){
if(resultCode == Activity.RESULT_OK){
setup();
}else{
Toast.makeText(this,
"BlueTooth NOT enabled",
Toast.LENGTH_SHORT).show();
finish();
}
}
}
private class ThreadConnectBTdevice extends Thread {
private BluetoothSocket bluetoothSocket = null;
private final BluetoothDevice bluetoothDevice;
public ThreadConnectBTdevice(BluetoothDevice device) {
bluetoothDevice = device;
try {
bluetoothSocket = device.createRfcommSocketToServiceRecord(myUUID);
textStatus.setText("bluetoothSocket: \n" + bluetoothSocket);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void run() {
boolean success = false;
try {
bluetoothSocket.connect();
success = true;
} catch (IOException e) {
e.printStackTrace();
final String eMessage = e.getMessage();
runOnUiThread(new Runnable(){
@Override
public void run() {
textStatus.setText("something wrong bluetoothSocket.connect(): \n" + eMessage);
}});
try {
bluetoothSocket.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
if(success){
//connect successful
runOnUiThread(new Runnable(){
@Override
public void run() {
textStatus.setText("connect successful");
}});
}else{
//fail
}
}
public void cancel() {
Toast.makeText(getApplicationContext(),
"close bluetoothSocket",
Toast.LENGTH_LONG).show();
try {
bluetoothSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
/res/layout/activity_main.xml
<LinearLayout 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"
android:orientation="vertical"
tools:context="com.example.androidbluetooth.MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:autoLink="web"
android:text="http://android-er.blogspot.com/"
android:textStyle="bold" />
<TextView
android:id="@+id/info"
android:textStyle="bold|italic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/status"
android:textSize="28sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<ListView
android:id="@+id/pairedlist"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
AndroidManifest.xml with permission of "android.permission.BLUETOOTH"
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.androidbluetooth"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.BLUETOOTH"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".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>
</manifest>
Download the files.
Next:
-
Bluetooth communication between Android devices
