Android Studio Incompatible Types

Question

I follow this tutorial to light on a LED with a phone. But I have an error in this code :

package com.irobotechart.controlbt;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
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.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.Set;

public class DevicesBT extends AppCompatActivity {

    //1)
    // Depuración de LOGCAT
    private static final String TAG = "DevicesBT"; //<-<- PARTE A MODIFICAR >->->
    // Declaracion de ListView
    ListView IdLista;
    // String que se enviara a la actividad principal, mainactivity
    public static String EXTRA_DEVICE_ADDRESS = "device_address";

    // Declaracion de campos
    private BluetoothAdapter mBtAdapter;
    private ArrayAdapter mPairedDevicesArrayAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_devices_bt);
    }

    @Override
    public void onResume()
    {
        super.onResume();
        //---------------------------------
        VerificarEstadoBT();

        // Inicializa la array que contendra la lista de los dispositivos bluetooth vinculados
        mPairedDevicesArrayAdapter = new ArrayAdapter(this, R.layout.name_devices);//<-<- PARTE A MODIFICAR >->->
        // Presenta los disposisitivos vinculados en el ListView
        IdLista = (ListView) findViewById(R.id.IdList);
        IdLista.setAdapter(mPairedDevicesArrayAdapter);
        IdLista.setOnItemClickListener(mDeviceClickListener);
        // Obtiene el adaptador local Bluetooth adapter
        mBtAdapter = BluetoothAdapter.getDefaultAdapter();
        // Obtiene un conjunto de dispositivos actualmente emparejados y agregua a 'pairedDevices'
        Set pairedDevices = mBtAdapter.getBondedDevices();
        // Adiciona un dispositivos previo emparejado al array
        if (pairedDevices.size() > 0)
        {
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            }
        }
    }

    // Configura un (on-click) para la lista
    private AdapterView.OnItemClickListener mDeviceClickListener = new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView av, View v, int arg2, long arg3) {

            // Obtener la dirección MAC del dispositivo, que son los últimos 17 caracteres en la vista
            String info = ((TextView) v).getText().toString();
            String address = info.substring(info.length() - 17);

            // Realiza un intent para iniciar la siguiente actividad
            // mientras toma un EXTRA_DEVICE_ADDRESS que es la dirección MAC.
            Intent i = new Intent(DevicesBT.this, UserInterface.class);//<-<- PARTE A MODIFICAR >->->
            i.putExtra(EXTRA_DEVICE_ADDRESS, address);
            startActivity(i);
        }
    };

    private void VerificarEstadoBT() {
        // Comprueba que el dispositivo tiene Bluetooth y que está encendido.
        mBtAdapter= BluetoothAdapter.getDefaultAdapter();
        if(mBtAdapter==null) {
            Toast.makeText(getBaseContext(), "El dispositivo no soporta Bluetooth", Toast.LENGTH_SHORT).show();
        } else {
            if (mBtAdapter.isEnabled()) {
                Log.d(TAG, "...Bluetooth Activado...");
            } else {
                //Solicita al usuario que active Bluetooth
                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                startActivityForResult(enableBtIntent, 1);

            }
        }
    }
}

The error is : Incompatible types : Found :'android.bluetooth.BluetoothDevice', require: 'java.lang.Object'

I don't know how I can solve this problem.

Thank you in advance for your help

I hope to be clear, I'm sorry if there are mistakes

Answer 1

You have used a Raw-type Set instead of generic mean, while using collections you can define the type of data and if you don't define then the type will be of Object

so use

Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();

instead of

Set pairedDevices = mBtAdapter.getBondedDevices();

Note : remove mBtAdapter = BluetoothAdapter.getDefaultAdapter(); from onresume it's redundant, already done in VerificarEstadoBT()

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Further Read

What is a raw type and why shouldn't we use it?