@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
 //Parte do Layout {
    //Botões
    buttonCadastro = (Button) findViewById(R.id.buttonCadastro);
    buttonListar = (Button) findViewById(R.id.buttonListar);
    buttonVoltar = (Button) findViewById(R.id.buttonVoltar);
    //EditTexts
    etNome = (EditText) findViewById(R.id.etNome);
    etData = (EditText) findViewById(R.id.etData);
    etRg = (EditText) findViewById(R.id.etRg);
    etCpf = (EditText) findViewById(R.id.etCpf);
    etEndereco = (EditText) findViewById(R.id.etEndereco);
    etDoenca = (EditText) findViewById(R.id.etDoenca);
    etProfissao = (EditText) findViewById(R.id.etProfissao);
    //TextViews
    textViewInfo = (TextView) findViewById(R.id.textViewInfo);
 //Parte do Layout }
    //-----------------------------------------------------------
    //BD
    bdR = FirebaseDatabase.getInstance().getReference();
    myRef = BD.getReference("-KSXUo45LKXpWMOX-BfY");

    //-----------------------------------------------------------

    buttonCadastro.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            novoUsuario = new Usuarios(
                    etNome.getText().toString(),
                    etData.getText().toString(),
                    etRg.getText().toString(),
                    etCpf.getText().toString(),
                    etEndereco.getText().toString(),
                    etDoenca.getText().toString(),
                    etProfissao.getText().toString());

            bdR.push().setValue(novoUsuario);

        }

    });

    buttonListar.setOnClickListener(new View.OnClickListener() {
        @Override

        public void onClick(View v) {
          myRef.addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                 Usuarios u = dataSnapshot.getValue(Usuarios.class);
                     Log.e("Meu: Nome", u.getNome());
                     Log.e("Meu: Data", u.getData());
                     Log.e("Meu: RG", u.getRg());
                     Log.e("Meu: CPF", u.getCpf());
                     Log.e("Meu: Endereço", u.getEndereco());
                     Log.e("Meu: Doença", u.getDoenca());
                     Log.e("Meu: Profissão", u.getProfissao());

                 }


                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });

        }
    });
}


public void abreInfo(View view){
    Intent intent = new Intent(this,Usuarios.class);
   startActivity(intent);
    setContentView(R.layout.activity_info);
}

}

private String Nome;
private String Data;
private String Rg;
private String Cpf;
private String Endereco;
private String Doenca;
private String Profissao;

public Usuarios(String Nome, String Data, String Rg, String Cpf, String Endereco, String Doenca, String Profissao) {
    this.Nome = Nome;
    this.Data = Data;
    this.Rg = Rg;
    this.Cpf = Cpf;
    this.Endereco = Endereco;
    this.Doenca = Doenca;
    this.Profissao = Profissao;
}
public Usuarios() {

}

myRef = BD.getReference("-KSXUo45LKXpWMOX-BfY");

//BD
    BD = FirebaseDatabase.getInstance();
    bdR = BD.getReference();
    myRef = BD.getReference("-KSXUo45LKXpWMOX-BfY");