[안드로이드 스튜디오 - 자바] 블루투스 연결_001

 
import android.bluetooth.BluetoothSocket;
import android.os.SystemClock;
 
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
 
public 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;
 
        // Get the input and output streams, using temp objects because
        // member streams are final
        try {
            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();
        } catch (IOException e) {
        }
 
        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }
 
    @Override
    public void run() {
        byte[] buffer = new byte[1024];  // buffer store for the stream
        int bytes; // bytes returned from read()
        // Keep listening to the InputStream until an exception occurs
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.available();
                if (bytes != 0) {
                    buffer = new byte[1024];
                    SystemClock.sleep(100); //pause and wait for rest of data. Adjust this depending on your sending speed.
                    bytes = mmInStream.available(); // how many bytes are ready to be read?
                    bytes = mmInStream.read(buffer, 0, bytes); // record how many bytes we actually read
                }
            } catch (IOException e) {
                e.printStackTrace();
 
                break;
            }
        }
    }
 
    /* Call this from the main activity to send data to the remote device */
    public void write(String input) {
        byte[] bytes = input.getBytes();           //converts entered String into bytes
        try {
            mmOutStream.write(bytes);
        } catch (IOException e) {
        }
    }
 
    /* Call this from the main activity to shutdown the connection */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) {
        }
    }
}

 

package com.example.mybluetooth001_002;
 
import android.Manifest;
import android.annotation.SuppressLint;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.SystemClock;
 
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
 
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.UUID;
 
public class MainActivity extends AppCompatActivity {
    TextView mTvBluetoothStatus;
    TextView mTvReceiveData;
    TextView mTvSendData;
    TextView mTvReceiveDataView;
    Button mBtnConnect;
    Button mBtnSendData;
 
    private BluetoothAdapter mBluetoothAdapter;
    Set<BluetoothDevice> mPairedDevices;
    List<String> mListPairedDevices;
 
    Handler mBluetoothHandler;
    ConnectedBluetoothThread mThreadConnectedBluetooth;
    BluetoothDevice mBluetoothDevice;
    BluetoothSocket mBluetoothSocket;
 
 
    final static int BT_MESSAGE_READ = 2;
    final static int BT_CONNECTING_STATUS = 3;
    final static UUID BT_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
 
 
    ConnectedThread connectedThread;
 
    //tag를 사용하기 위한 선언
    private static final String TAG = "MainActivity";
    private int readBufferPosition; // 버퍼 내 문자 저장 위치
 
    private BluetoothGatt mBluetoothGatt;
 
 
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
 
 
        //블루투스가 되는지 설정
        if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
            Toast.makeText(this, "블루투스 미지원 기기입니다.", Toast.LENGTH_SHORT).show();
            finish();
        }
 
        //권한 설정
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            requestPermissions(
                    new String[]{
                            Manifest.permission.BLUETOOTH,
                            Manifest.permission.BLUETOOTH_SCAN,
                            Manifest.permission.BLUETOOTH_ADVERTISE,
                            Manifest.permission.BLUETOOTH_CONNECT,
                            Manifest.permission.ACCESS_FINE_LOCATION,
                            Manifest.permission.ACCESS_COARSE_LOCATION
                    },
                    1);
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            requestPermissions(
                    new String[]{
                            Manifest.permission.BLUETOOTH
 
                    },
                    1);
        }
 
        mTvBluetoothStatus = (TextView)findViewById(R.id.tvBluetoothStatus);
        mTvReceiveData = (TextView)findViewById(R.id.tvReceiveData);
        mTvReceiveDataView = (TextView)findViewById(R.id.tvReceiveDataView);
        mTvSendData =  (EditText) findViewById(R.id.tvSendData);
        mBtnConnect = (Button)findViewById(R.id.btnConnect);
        mBtnSendData = (Button)findViewById(R.id.btnSendData);
 
        // 블루투스 기능을 지원하는지 알아오는 메서드
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        //mBluetoothLeScanner = mBluetoothAdapter.getBluetoothLeScanner();
        //mBluetoothLeAdvertiser = mBluetoothAdapter.getBluetoothLeAdvertiser();
        // Initializes Bluetooth adapter.
        final BluetoothManager bluetoothManager =
                (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
        mBluetoothAdapter = bluetoothManager.getAdapter();
 
 
        // 버튼 눌렀을 때 동작하는 기능들
        mBtnConnect.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View view) {
                listPairedDevices();
            }
        });
        mBtnSendData.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(mThreadConnectedBluetooth != null) {
                    mThreadConnectedBluetooth.write(mTvSendData.getText().toString());
                    mTvSendData.setText("");
                }
            }
        });
 
        // 블루투스 핸들러로 연결 뒤, 수신된 데이터를 읽어와 ReceiveData텍스트 뷰에 표시해주는 부분
        mBluetoothHandler = new Handler(Looper.getMainLooper()){
            public void handleMessage(android.os.Message msg){
                if(msg.what == BT_MESSAGE_READ){
                    String readMessage = null;
                    try {
                        readMessage = new String((byte[]) msg.obj, "UTF-8");
                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    }
                    mTvReceiveData.setText(readMessage);
                }
            }
        };
    }
 
    void listPairedDevices() {
 
        // 블루투스 활성화 상태 확인
        try{
            if (mBluetoothAdapter.isEnabled()) {
                // 이미 Paired된 Device목록을 얻어옴
                mPairedDevices = mBluetoothAdapter.getBondedDevices();
 
                //페어링 된 장치가 존재한다면 새로운 알림창을 생성
                if (mPairedDevices.size() > 0) {
                    AlertDialog.Builder builder = new AlertDialog.Builder(this);
                    builder.setTitle("장치 선택");
 
                    mListPairedDevices = new ArrayList<String>();
                    for (BluetoothDevice device : mPairedDevices) {
                        mListPairedDevices.add(device.getName());
                        //mListPairedDevices.add(device.getName() + "\n" + device.getAddress());
                    }
                    final CharSequence[] items = mListPairedDevices.toArray(new CharSequence[mListPairedDevices.size()]);
                    mListPairedDevices.toArray(new CharSequence[mListPairedDevices.size()]);
 
                    //장치를 누르면 connectSelectedDevice로 전달
                    builder.setItems(items, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int item) {
                            for (BluetoothDevice device : mPairedDevices) {
                                if (device.getName().equals(items[item].toString())) {
                                    connectSelectedDevice(String.valueOf(device));
                                    break;
                                }
                            }
                        }
                    });
                    // 알림창을 뛰어줌
                    AlertDialog alert = builder.create();
                    alert.show();
                } else {
                    Toast.makeText(getApplicationContext(), "페어링된 장치가 없습니다.", Toast.LENGTH_LONG).show();
                }
            }
            else {
                Toast.makeText(getApplicationContext(), "블루투스가 비활성화 되어 있습니다.", Toast.LENGTH_SHORT).show();
            }
 
        }catch (SecurityException e)
        {
            e.printStackTrace();
        }
 
    }
 
    // listPairedDevices를 통하여 전달받은 매개변수 값은 장치 이름
    @SuppressWarnings({"MissingPermission"})
    private void connectSelectedDevice(String address) {
        BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
        mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
    }
 
    private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
        @SuppressLint("MissingPermission")
        @Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
            super.onConnectionStateChange(gatt, status, newState);
            if (newState == BluetoothProfile.STATE_CONNECTED) {
                gatt.discoverServices();
            } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
                mBluetoothGatt.close();
                mBluetoothGatt = null;
            }
        }
 
        @Override
        public void onServicesDiscovered(BluetoothGatt gatt, int status) {
            super.onServicesDiscovered(gatt, status);
            // do something with the services
        }
    };
 
 
    @SuppressLint("MissingPermission")
    private BluetoothSocket createBluetoothLEConnection(BluetoothDevice device) {
        BluetoothSocket socket = null;
        try {
            socket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return socket;
    }
 
    @SuppressLint("MissingPermission")
    private BluetoothGatt connectGatt(BluetoothDevice device) {
        return device.connectGatt(this, false, mGattCallback);
    }
 
    @SuppressWarnings({"MissingPermission"})
    private class ConnectedBluetoothThread extends Thread {
 
        private final BluetoothSocket mmSocket;
        private InputStream mmInStream;
        private OutputStream mmOutStream;
 
        //쓰레드 초기화
        public void run() {
            readBufferPosition = 0;
            byte[] buffer = new byte[1024];
            int bytes;
 
            //데이터를 지속적으로 확인하는...
            while (true) {//계속 확인하는 중인데 어떻게 안보내진다
                try {
                    //inputStream 계속 읽기(값을 받는다)
                    //bytes = mmInStream.available();
                    bytes = mmInStream.read(buffer);
                    String incomingMessage = new String(buffer, 0, bytes);
                    Log.d(TAG, "Input Stream : " + incomingMessage);
 
                    if (bytes >= 0) {
                        SystemClock.sleep(100);
                        bytes = mmInStream.available();
                        bytes = mmInStream.read(buffer, 0, bytes);
                        mBluetoothHandler.obtainMessage(BT_MESSAGE_READ, bytes, -1, buffer).sendToTarget();
 
                    }
                } catch (IOException e) {
                    try {
                        mmSocket.connect();
                    } catch (IOException ex) {
                        Log.e(TAG, "Unable to connect to socket", ex);
                        break;
                    }
                }
            }
        }
 
        public ConnectedBluetoothThread(BluetoothSocket socket) {
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;
 
            // 소켓을 통한 전송을 처리
            // BluetoothSocket의 inputstream 과 outputstream을 얻는다.
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
                Toast.makeText(getApplicationContext(), "소켓 연결 중 오류가 발생했습니다.", Toast.LENGTH_LONG).show();
            }
            mmInStream = tmpIn;
            mmOutStream = tmpOut;
 
        }
 
        //데이터 전송을 위한 스레드 메서드
        public void write(String str) {
            byte[] bytes = str.getBytes();
 
            try {
                //값을 쓰는 부분(값을 보낸다.)
                mmOutStream.write(bytes);
            } catch (IOException e) {
                //e: "java.io.IOException: socket closed"
                Toast.makeText(getApplicationContext(), "데이터 전송 중 오류가 발생했습니다.", Toast.LENGTH_LONG).show();
 
                // 소켓을 다시 생성하고 연결한다.
                try {
                    mBluetoothSocket = mBluetoothDevice.createRfcommSocketToServiceRecord(BT_UUID);
                    mBluetoothSocket.connect();
                    mmOutStream = mBluetoothSocket.getOutputStream();
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
        }
 
        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                Toast.makeText(getApplicationContext(), "소켓 해제 중 오류가 발생했습니다.", Toast.LENGTH_LONG).show();
            }
        }
    }
 
 
 
 
}

 

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
 
 
 
    <Button
        android:id="@+id/btnConnect"
        android:layout_width="wrap_content"
        android:layout_height="0dp"

        android:layout_marginStart="30dp"
        android:layout_marginLeft="30dp"
        android:layout_marginTop="30dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:text="연결하기"
        app:layout_constraintTop_toBottomOf="@+id/tvBluetoothStatus" />
 
    <TextView
        android:id="@+id/tvBluetoothStatus"
        android:layout_width="170dp"
        android:layout_height="20dp"
        android:layout_marginStart="8dp"
        android:text="status"
        app:layout_constraintBottom_toBottomOf="@+id/btnConnect"
        app:layout_constraintStart_toEndOf="@+id/btnConnect"
        app:layout_constraintTop_toTopOf="@+id/btnConnect" />
 
 
 
    <TextView
        android:id="@+id/tvReceiveData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="Receive"
        app:layout_constraintStart_toStartOf="@+id/btnSendData"
        app:layout_constraintTop_toBottomOf="@+id/btnSendData" />
 
 
    <TextView
        android:id="@+id/tvReceiveDataView"
        android:layout_width="307dp"
        android:layout_height="427dp"
        android:layout_marginBottom="128dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="@+id/tvReceiveData" />
 
    <Button
        android:id="@+id/btnSendData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="전송"
        app:layout_constraintStart_toStartOf="@+id/btnConnect"
        app:layout_constraintTop_toBottomOf="@+id/btnConnect" />
 
    <EditText
        android:id="@+id/tvSendData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:ems="10"
        android:inputType="textPersonName"
        android:text="Send Data"
        app:layout_constraintStart_toEndOf="@+id/btnSendData"
        app:layout_constraintTop_toTopOf="@+id/btnSendData" />
 
</androidx.constraintlayout.widget.ConstraintLayout>

 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
 
    <!-- 블루투스 사용하기 위해 정의 -->
    <uses-permission
        android:name="android.permission.BLUETOOTH"
        android:maxSdkVersion="30" />
    <!-- 장치를 찾거나 블루투스 설정을 관리 -->
    <uses-permission
        android:name="android.permission.BLUETOOTH_ADMIN"
        android:maxSdkVersion="30" />
 
    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
    <uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
 
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
 
    <!-- 저전력 블루투스(지원하지 않는 기기에도 앱 제공 -->
    <uses-feature android:name="android.hardware.bluetooth_le" android:required="false"/>
 
 
    <uses-feature
        android:name="android.hardware.bluetooth"
        android:required="true" />
 
    <uses-feature
        android:name="android.hardware.bluetooth_le"
        android:required="false" />
 
    <uses-feature
        android:name="android.hardware.location.gps"
        android:required="true" />
 
    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyBluetooth001_002"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
 
            <meta-data
                android:name="android.app.lib_name"
                android:value="" />
        </activity>
    </application>
 
</manifest>

아직 완성된 건 아니고 일단 연결을 하는건데

 

핸드폰의 블루투스를 키고 - 대상 기기를 연결한 후 어플내에서 다시 연결을 해줘야한다.

 

권한은 있는데로 다 넣어줬다 혹시 몰라서..