Sending data to MYSQL database with PHP

In my code below I send the data I need for PHP and it inserts the data into the MySQL Database. When I click the register button, I send the data through a HashMap, as I would to send the data. idcliente too, which in the case is "int" ... Can you help me in this detail? Here is the code below.

public class RegistrarActivity extends AppCompatActivity {

private ImageView botaoVoltar;
private Button botaoRegistrar;
private EditText textoCPF, textoEmail;
private Spinner spinnerCliente;
private Cliente cliente;
private int idcliente;
private ArrayList<Cliente> clientes = new ArrayList<>();
private RequestQueue requestQueue, requestQueue2;
private static final String URL = "http://www.caixinhadosmotoristas.com.br/spinner-cliente.php";
private static final String URLReg = "http://www.caixinhadosmotoristas.com.br/validacao.php?acao=register";
private StringRequest request, request2;
private ArrayAdapter arrayAdapter;

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

    botaoVoltar = (ImageView) findViewById(R.id.botaoVoltarId);
    botaoRegistrar = (Button) findViewById(R.id.botaoRegistrarId);
    textoCPF = (EditText) findViewById(R.id.textoCpfId);
    textoEmail = (EditText) findViewById(R.id.textoEmailId);
    spinnerCliente = (Spinner) findViewById(R.id.spinnerClienteId);

    requestQueue = Volley.newRequestQueue(this);
    requestQueue2 = Volley.newRequestQueue(this);

    RetornaJSONClientes();

    ArrayAdapter arrayAdapter = new ArrayAdapter (this, android.R.layout.simple_spinner_dropdown_item, clientes);
    arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerCliente.setAdapter(arrayAdapter);

    spinnerCliente.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            cliente = (Cliente) parent.getItemAtPosition(position);
            idcliente = cliente.getId();
            Toast.makeText(RegistrarActivity.this, "" + idcliente, Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
            cliente = null;
        }
    });

    SimpleMaskFormatter mascaraCPF = new SimpleMaskFormatter("NNN.NNN.NNN-NN");
    MaskTextWatcher maskCPF = new MaskTextWatcher(textoCPF, mascaraCPF);
    textoCPF.addTextChangedListener(maskCPF);

    botaoRegistrar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            request2 = new StringRequest(Request.Method.POST, URLReg, new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    try {
                        JSONObject jsonObject = new JSONObject(response);
                        if (jsonObject.names().get(0).equals("200")){
                            Toast.makeText(getApplicationContext(), jsonObject.getString("mensagem"), Toast.LENGTH_LONG).show();
                        } else {
                            Toast.makeText(getApplicationContext(), jsonObject.getString("mensagem"), Toast.LENGTH_LONG).show();
                        }
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {

                }
            }){
                @Override
                protected Map<String, String> getParams() throws AuthFailureError {
                    HashMap<String, String> hashMap = new HashMap<String, String>();
                    hashMap.put("nome", cliente.getNome());
                    hashMap.put("cpf2", textoCPF.getText().toString());
                    hashMap.put("email", textoEmail.getText().toString());
                    return hashMap;
                }
            };

            requestQueue2.add(request2);
        }
    });

    botaoVoltar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent voltaLogin = new Intent(RegistrarActivity.this, LoginActivity.class);
            startActivity(voltaLogin);
        }
    });
}

private void RetornaJSONClientes(){
    request = new StringRequest(Request.Method.POST, URL, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            String jsonString;
            int jsonInt;

            try {
                JSONArray jsonArray = new JSONArray(response);

                ArrayAdapter arrayAdapter = (ArrayAdapter) spinnerCliente.getAdapter();
                arrayAdapter.setNotifyOnChange(false);

                for(int i = 0; i < jsonArray.length(); i++){
                    jsonString = jsonArray.getJSONObject(i).getString("nome");
                    jsonInt = jsonArray.getJSONObject(i).getInt("idcliente");

                    clientes.add(new Cliente(jsonInt, jsonString));
                }

                arrayAdapter.setNotifyOnChange(true);
                arrayAdapter.notifyDataSetChanged();
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {

        }
    });

    requestQueue.add(request);
}

}