Saving data to TextView on different activity
<p>On home screen of my app I want to have various <code>TextViews</code> that initially hold only "..." for data, until user inputs his data.</p>

<p>User inputs data in different activity that opens when <code>CardView</code> that holds all "..." values is clicked.</p>

<p>I constantly get NullPointerException</p>

<pre><code>02-26 16:14:33.106 26275-26275/hr.app.liftme.liftmehr E/AndroidRuntime: FATAL EXCEPTION: main
    Process: hr.app.liftme.liftmehr, PID: 26275                                                               

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
    at hr.app.liftme.liftmehr.StatistikeInputMain$1.onClick(StatistikeInputMain.java:54)
    at android.view.View.performClick(View.java:4856)
    at android.view.View$PerformClick.run(View.java:19956)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:211)
    at android.app.ActivityThread.main(ActivityThread.java:5389)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1020)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:815)
</code></pre>

<p>Here's my java file</p>

<pre><code>public class StatistikeInputMain extends AppCompatActivity {
    RadioGroup radioGrupa;
    RadioButton imperial, metric;
    EditText visinaCM, visinaFT, visinaINC, tezina, bodyfat, tdee;
    Spinner kolikoDugoTrenirate, cilj;
    TextView rezultatTDEE;
    Button spremiRezultat;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_statistike_input_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        radioGrupa = (RadioGroup) findViewById(R.id.radioGrupaStatistike);
        imperial = (RadioButton) findViewById(R.id.radioStatistikeImperial);
        metric = (RadioButton) findViewById(R.id.radioStatistikeMetric);
        visinaCM = (EditText) findViewById(R.id.editTextStatistikeVisinaCM);
        visinaFT = (EditText) findViewById(R.id.editTextStatistikeVisinaFEET);
        visinaINC = (EditText) findViewById(R.id.editTextStatistikeVisinaINCH);
        tezina = (EditText) findViewById(R.id.editTextStatistikeTezina);
        bodyfat = (EditText) findViewById(R.id.editTextStatistikeBF);
        tdee = (EditText) findViewById(R.id.editTextStatistikeTDEE);
        kolikoDugoTrenirate = (Spinner) findViewById(R.id.spinnerStatistikeKolikoDugoTrenirate);
        cilj = (Spinner) findViewById(R.id.spinnerStatistikeCilj);
        spremiRezultat = (Button) findViewById(R.id.buttonStatistikeSpremi);
        rezultatTDEE = (TextView) findViewById(R.id.textViewStatistikeRezultatTDEE);

        spremiRezultat.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                double unosTDEE = Double.parseDouble(tdee.getText().toString());

                double rezultatTDEEInput = 0;
                rezultatTDEE.setText(Double.toString(rezultatTDEEInput));
            }
        });
    }
}
</code></pre>

<p>Note that error occurs on this line</p>

<pre><code>rezultatTDEE.setText(Double.toString(rezultatTDEEInput));
</code></pre>

<p>I want data to be saved on this Text View</p>

<pre><code> &lt;TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="..."
    android:id="@+id/textViewStatistikeRezultatTDEE"
    android:textSize="14sp" /&gt;
</code></pre>

<p>That is initiallized and casted in java file..</p>

<p>Another note - data is saved when the button is pressed!</p>

<p>What am I missing here?</p>

<p>EDIT</p>

<ol>
<li><p>activity</p>

<pre><code>spremiRezultat.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = new Intent(getApplicationContext(), AppLayoutMain.class);
        intent.putExtra("tdeeInput", tdee.getText().toString());
        startActivity(intent);
</code></pre></li>
<li><p>activity</p>

<pre><code>Intent intent = getIntent();
String tdee = intent.getStringExtra("tdeeInput");
</code></pre></li>
</ol>

<p>I did it this way, only way that it doesn't give error, button works fine but it still doesn't display results.</p>