Error when connecting external database

Question

The following error appears

E/MYSQL: Erro: java.lang.ClassNotFoundException: org.sqlite.JDBC.Driver
E/MYSQL: Erro: java.sql.SQLException: No suitable driver
E/MYSQL: Erro: java.lang.NullPointerException: Attempt to invoke interface method 'java.sql.ResultSet java.sql.Statement.executeQuery(java.lang.String)' on a null object reference
E/MYSQL: Erro: java.lang.NullPointerException: Attempt to invoke interface method 'void java.sql.Connection.close()' on a null object reference

Connection class package com.example.Jonathan.agendaonline;

import android.app.Activity; import android.util.Log;

import java.sql.Connection; import java.sql.Drivermanager; import java.sql.Resultset; import java.sql.Statement; import java.sql.Driver;

/** * Created by Jonathan on 26/10/2016. */

public class Bancoconexao { private Static Connection Conn = null; private Static Statement st; private Static Resultset rs; private string sql;

    public static void conectarMySQL(String host, String porta, String banco, String usuario, String senha) {
        try {
            Class.forName("org.sqlite.JDBC.Driver");
        } catch (Exception erro) {
            Log.e("MYSQL", "Erro: " + erro);
        }
        try {
            conn = DriverManager.getConnection("jdbc:mysql://" + host + ":" + porta + "/" + banco, usuario, senha);
            Log.i("MYSQL", "Conectado.");
        } catch (Exception erro) {
            Log.e("MYSQL", "Erro: " + erro);
        }
    }


    public static void desconectarMySQL() {
        try {
            conn.close();
            Log.i("MYSQL", "Desconectado.");
        } catch (Exception erro) {
            Log.e("MYSQL", "Erro: " + erro);
        }
    }

    public static void queryMySQL(String sql) {
        try {
            if (conn == null || st == null)
                st.executeQuery(sql);

            Log.i("MYSQL", "Resultado: " + rs.getString("nome"));
        } catch (Exception erro) {
            Log.e("MYSQL", "Erro: " + erro);
        }
    }

    public ResultSet getData(String sql) throws Exception {

        if (conn == null || st == null)
            conectarMySQL("172.0.0.1", "64533", "AgendaColetiva", "root", "root");
        return st.executeQuery(sql);
    }

}

Class using the seat

 package com.example.jonathan.agendaonline;

 import android.content.Intent;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;

 public class CriarUsuario extends AppCompatActivity { 

TextView nome,senha,email;
String nomeS,senhaS,emailS;
Button criar;
Usuario usuario;
int tipo = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_criar_usuario);
    nome = (EditText) findViewById(R.id.nome);
    senha = (EditText) findViewById(R.id.senha);
    email = (EditText) findViewById(R.id.email);
    criar = (Button) findViewById(R.id.Criar);
    criar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            nomeS = nome.getText().toString();
            senhaS = senha.getText().toString();
            emailS = email.getText().toString();
            try {
                BancoConexao.conectarMySQL("172.0.0.1", "64533", "AgendaColetiva", null, null);
                String sql = String.format("INSERT INTO Usuarios ("
                                + nomeS
                                + senhaS
                                + emailS
                                +tipo
                                + ") VALUES(?,?,?,?)");
                BancoConexao.queryMySQL(sql);
                Toast.makeText(getApplicationContext(),"Cadastro bem sussedido", Toast.LENGTH_LONG).show();
                BancoConexao.desconectarMySQL();
                finish();

            } catch (Exception e) {
                e.printStackTrace();
            }





        }

    });



}

}