how do I stop a sum?

Question

I’m making an app where I have to pull a sensor (I used the accelerometer) and save the sum of the 3 parameters.

As soon as I try to save that sum the app hangs, I found that the save command that is causing it to crash, someone knows what is wrong ?

from now on thank.

Below is the main code:

package com.example.dfabr.primeiroprograma;

import android.content.Intent;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
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;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;


import static com.example.dfabr.primeiroprograma.R.id.nomeArqTxt;
import static com.example.dfabr.primeiroprograma.R.id.txtDigitado;

public class telaInformacao extends AppCompatActivity implements SensorEventListener {


    public EditText txtSoma;
    private Button btnSalvarSoma;
    Sensor accelerometer;
    SensorManager sensorManager;






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



        sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
        accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        sensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);


        btnSalvarSoma = (Button) findViewById(R.id.btnSalvarSoma);

        btnSalvarSoma.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                try  {
                   // EditText nomeArquivo = (EditText) findViewById(R.id.nomeArqTxt);
                    EditText txtDigitado = (EditText) findViewById(R.id.txtDigitado);
                    FileOutputStream gravarTexto = openFileOutput(txtDigitado.getText().toString(), MODE_APPEND);
                    String conteudoTxt = txtDigitado.getText().toString();
                    gravarTexto.write(conteudoTxt.getBytes());
                    gravarTexto.close();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
               //Toast.makeText(telaTexto.this, "Arquivo Gravado Com Sucesso", Toast.LENGTH_LONG).show();
                Intent intent = new Intent(telaInformacao.this, MainActivity.class);
                startActivity(intent);
            }
        });

    }


    @Override
    public void onSensorChanged(SensorEvent event) {

        Sensor accelerometer;
        SensorManager sensorManager;

        float sensorX;
        float sensorY;
        float sensorZ;

        sensorX = event.values[0];
        sensorY = event.values[1];
        sensorZ = event.values[2];
        float soma = (event.values[0] + event.values[1] + event.values[2]);



        TextView tx = (TextView) findViewById(R.id.tX);
        TextView ty = (TextView) findViewById(R.id.tY);
        TextView tz = (TextView) findViewById(R.id.tZ);
        TextView ta = (TextView) findViewById(R.id.txtSoma);
        tx.setText("X: " + (sensorX));
        ty.setText("Y: " + (sensorY));
        tz.setText("Z: " + (sensorZ));
        ta.setText("Soma: " + (soma));





    }


    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }


}

error below.

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.example.dfabr.primeiroprograma, PID: 20680
              java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
                  at com.example.dfabr.primeiroprograma.telaInformacao$1.onClick(telaInformacao.java:60)
                  at android.view.View.performClick(View.java:6897)
                  at android.widget.TextView.performClick(TextView.java:12693)
                  at android.view.View$PerformClick.run(View.java:26101)
                  at android.os.Handler.handleCallback(Handler.java:789)
                  at android.os.Handler.dispatchMessage(Handler.java:98)
                  at android.os.Looper.loop(Looper.java:164)
                  at android.app.ActivityThread.main(ActivityThread.java:6944)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)

Answer 1

You didn’t initialize yours EditText;

You stated public EditText txtSoma; but needs to initialize.

For example:
txtSoma = findviewbyid(R.id.txtSoma);

Answer 2

Try putting a try, at least avoid crashing, can make treatments errors

sensorX = event.values[0];  
sensorY = event.values[1];  
sensorZ = event.values[2];  

float soma = 0.00;
try {    
  soma = (sensorX + sensorY  + sensorZ); 
} 
catch (NumberFormatException e) {
  soma = 0.00;
//tratamento de erro
}