Where is the error in my codes?

Why is it my app forced closed when I click on stock availability button?

AvailButton_main.java

public class AvailButton_main extends BaseActivity {

    private Nearable currentNearable;
    TextView ASM, AQ, ASA, ACA;
    Spinner SpinnerSA, SpinnerCA;

    private Database_availability dba;
    Availresult Adbrow;



    @Override
    protected int getLayoutResId() {
        return R.layout.nearable_demo;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.avail_2);
        currentNearable = getIntent().getExtras().getParcelable(ListNearablesActivity.EXTRAS_NEARABLE);


        ASM = (TextView) findViewById(R.id.ashoemodel);
        AQ = (TextView) findViewById(R.id.aquan);
        ASA = (TextView) findViewById(R.id.sizea);
        ACA = (TextView) findViewById(R.id.clra);

        SpinnerSA = (Spinner) findViewById(R.id.spinnersizea);
        SpinnerCA = (Spinner) findViewById(R.id.spinnerclra);



        toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setNavigationIcon(R.drawable.ic_action_navigation_arrow_back);
        toolbar.setTitle(getTitle());
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onBackPressed();
            }
        });

        displayStockAvailInfo();

        String[] asize = dba.getSizeAvail(currentNearable.identifier);
        ArrayAdapter<String> adapter= new ArrayAdapter<>
                (this,android.R.layout.simple_spinner_item, asize);  //for size available
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        SpinnerSA.setAdapter(adapter);

        String[] acolour = dba.getColourAvail(currentNearable.identifier);
        ArrayAdapter<String> adapter1= new ArrayAdapter<>
                (this,android.R.layout.simple_spinner_item, acolour); //for colours available
        adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        SpinnerCA.setAdapter(adapter1);
    }



    private void displayStockAvailInfo() {
        dba = new Database_availability(this);
        Adbrow = dba.getResultAvail(currentNearable.identifier);
        Adbrow.getIdentifieravail();
        Adbrow.getIdavail();


        String shoemodel = Adbrow.getSmavail().toString();
        Adbrow.getCaavail().toString();
        Adbrow.getSaavail().toString();

        //Set the text to the TextView
        ASM.setText(shoemodel);
        ACA.setText(Adbrow.getQuantityavail());

    }
    }

ListNearablesActivity.java

public class ListNearablesActivity extends BaseActivity {

    private static final String TAG = ListNearablesActivity.class.getSimpleName();
    public static final String EXTRAS_TARGET_ACTIVITY = "extrasTargetActivity";
    public static final String EXTRAS_NEARABLE = "extrasNearable";
    private static final int REQUEST_ENABLE_BT = 1234;

    private BeaconManager beaconManager;
    private NearableListAdapter adapter;

    private String scanId;

    @Override
    protected int getLayoutResId() {
        return R.layout.main;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Configure device list.
        adapter = new NearableListAdapter(this);
        ListView list = (ListView) findViewById(R.id.device_list);
        list.setAdapter(adapter);
        list.setOnItemClickListener(createOnItemClickListener());

        //Initialize Beacon Manager
        beaconManager = new BeaconManager(this);


    }

    @Override
    protected void onDestroy() {
        beaconManager.disconnect();
        super.onDestroy();
    }

    @Override
    protected void onStart() {
        super.onStart();

        // Check if device supports Bluetooth Low Energy.
        if (!beaconManager.hasBluetooth()) {
            Toast.makeText(this, "Device does not have Bluetooth Low Energy", Toast.LENGTH_LONG).show();
            return;
        }

        // If Bluetooth is not enabled, let user enable it.
        if (!beaconManager.isBluetoothEnabled()) {
            Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
        } else {
            connectToService();
        }
    }

    @Override
    protected void onStop() {
        beaconManager.disconnect();
        super.onStop();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_ENABLE_BT) {
            if (resultCode == Activity.RESULT_OK) {
                connectToService();
            } else {
                Toast.makeText(this, "Bluetooth not enabled", Toast.LENGTH_LONG).show();
                toolbar.setSubtitle("Bluetooth not enabled");
            }
        }
        super.onActivityResult(requestCode, resultCode, data);
    }

    private void connectToService() {
        toolbar.setSubtitle("Scanning...");
        adapter.replaceWith(Collections.<Nearable>emptyList());

        beaconManager.setNearableListener(new BeaconManager.NearableListener() {
            @Override
            public void onNearablesDiscovered(List<Nearable> nearables) {
                toolbar.setSubtitle("Found shoes: " + nearables.size());
                adapter.replaceWith(nearables);
                for (Nearable nearable : nearables) {
                    if (nearable.isMoving) {
                        try {
                            Class<?> clazz = Class.forName(getIntent().getStringExtra(EXTRAS_TARGET_ACTIVITY));
                            Intent intent = new Intent(ListNearablesActivity.this, clazz);
                            intent.putExtra(EXTRAS_NEARABLE, adapter.getItem(nearables.indexOf(nearable)));
                            startActivity(intent);
                        } //close for try
                        catch (ClassNotFoundException e) {
                            Log.e(TAG, "Finding class by name failed", e);
                        } //close for catch (ClassNotFoundException e)
                    }
                }
            } //for override
        });  //for beaconManager.setNearable

        beaconManager.connect(new BeaconManager.ServiceReadyCallback() {
            @Override
            public void onServiceReady() {
                scanId = beaconManager.startNearableDiscovery();
            } //for onServiceReady
        }); //for .connect
    } //for private void connectToService

    private AdapterView.OnItemClickListener createOnItemClickListener() {
        return new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
                if (getIntent().getStringExtra(EXTRAS_TARGET_ACTIVITY) != null){
                    try {
                        Class<?> clazz = Class.forName(getIntent().getStringExtra(EXTRAS_TARGET_ACTIVITY));
                        Intent intent = new Intent(ListNearablesActivity.this, clazz);
                        intent.putExtra(EXTRAS_NEARABLE, adapter.getItem(position));
                        startActivity(intent);
                    } //close for try
                    catch (ClassNotFoundException e) {
                        Log.e(TAG, "Finding class by name failed", e);
                    } //close for catch (ClassNotFoundException e)
                } //close for getintent.getStringExtra()
            } //close for public void onitemclick
        };   //close for return new adapterview
    }  //close for private adapter
}