Android Bluetooth connection to send and receive data (excluding BLE)

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This code has been verified by the project and is completely OK

Directly go to the Code step:

Private descrithadapter adapter;

1. // obtain the Bluetooth adapter

Adapter = descrithadapter. getdefaadapter adapter ();

// Enable Bluetooth
If (! Adapter. isEnabled ()){
// The pop-up dialog box prompts you to select whether to enable Bluetooth
Intent intent = new Intent (effecthadapter. ACTION_REQUEST_ENABLE );
StartActivityForResult (intent, 0 );
// Or enable it without prompting
// BAdapter. enable ();
}

2. Get Bluetooth MacAddress

// Search for and obtain the paired Bluetooth
NameAddress = getmediareddevice (adapter); // Add a definition for the variable

// Obtain the name list and address list
If (nameAddress. size ()> 0 ){
BlueNames = nameAddress. get (0 );
BlueAddress = nameAddress. get (1 );
}

// Obtain the method. Here, I store the name and address in the set separately. To facilitate display in the ListView and other purposes, you can return the address as needed or only.

Private ArrayList <String> getmediareddevice (descrithadapter adapter ){
ArrayList <String> nameAndAddress = new ArrayList <String> ();
// Optional reddevicenames = new ArrayList <String> ();
Optional reddeviceaddress = new ArrayList <String> ();
Set <shortthdevice> repeated reddevices = adapter. getBondedDevices ();
If (repeated reddevices. size ()> 0 ){
// Parse them one by one
For (incluthdevice devices: inclureddevices ){
// Put it into the set
PairedDeviceNames. add (devices. getName () + "\ n"
+ Devices. getAddress ());
PairedDeviceAddress. add (devices. getAddress ());
}
// Save information
NameAndAddress. add (pairedDeviceNames );
NameAndAddress. add (pairedDeviceAddress );
}
Return nameAndAddress;
}

3. Connect to the bluetooth device through Address

// Connect the device
Device = adapter. getRemoteDevice (address );
Connect (device );

Public synchronized void connect (effecthdevice device ){

ConnectThread = new ConnectThread (device, this, adapter, handler, handlerUpdate );
ConnectThread. start ();
}

4. connect to a Bluetooth thread

Public class ConnectThread extends Thread {

// The variable is omitted here

Public ConnectThread (effecthdevice device, effecthadapter mAdapterr ){
This. mAdapter = mAdapter;
Int sdk = Build. VERSION. SDK_INT;
If (sdk> = 10 ){
Try {
MySocket = device
. CreateInsecureRfcommSocketToServiceRecord (MY_UUID );
} Catch (IOException e ){
E. printStackTrace ();
}
} Else {
Try {
MySocket = device. createRfcommSocketToServiceRecord (MY_UUID );
} Catch (IOException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}
}

}

Public void run (){
//
MAdapter. cancelDiscovery ();
Try {
MySocket. connect ();
// Start receiving data sent from a remote device
ConnectBluetooth = new ReceiveDatas (mySocket, receiveHandler );
ConnectBluetooth. start ();
// Output stream
MmOutStream = mySocket. getOutputStream ();
} Catch (IOException e ){
// TODO Auto-generated catch block

Try {
MySocket. close ();
} Catch (IOException ee ){
// TODO Auto-generated catch block
Ee. printStackTrace ();
}

}

}

// Write data
/* Call this from the main Activity to send data to the remote device */
Public void sendMessage (String msg ){
Byte [] buffer = new byte [16];
Try {
If (mmOutStream = null ){
Log. I ("info", "the output stream is empty ");
Return;
}
// Write data
Buffer = msg. getBytes ();
MmOutStream. write (buffer );
} Catch (IOException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Finally {
Try {
If (mmOutStream! = Null ){
MmOutStream. flush ();
}
} Catch (IOException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}
}
}

}

5. Read data

Public class ReceiveDatas extends Thread {
// The variable is skipped.

// Constructor
Public ReceiveDatas (javasthsocket socket ){

This. mmSocket = socket;
InputStream tempIn = null;

// Obtain the input stream
Try {
TempIn = socket. getInputStream ();
} Catch (IOException e ){
// TODO Auto-generated catch block
}
MmInStream = tempIn;
}

@ Override
Public void run (){
Byte [] buffer = new byte [1024]; // buffered data stream
Int bytes; // return the data read.
// Listen to the input stream
While (true ){
Try {
Bytes = mmInStream. read (buffer );
// Process data here ......

} Else {
Log. I ("info", "exception ");
}
} Catch (IOException e ){
Try {
If (mmInStream! = Null ){
MmInStream. close ();
}
Log. I ("info", "exception ");
Break;
} Catch (IOException e1 ){
// TODO Auto-generated catch block
E1.printStackTrace ();
}
}
Try {
Thread. sleep (50); // Delay
} Catch (InterruptedException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
}
}
}