title: .getExtras()' on a null object reference
body: <p>I am trying to pass a few values between my activities to make a game work. However, the new activity after passing the information always returns null when I try to .getExtras(). </p>
  
  <p>Any thoughts? </p>
  
  <p>Code: </p>
  
  <pre><code>package name.zerosum;
  
  import android.content.Intent;
  import android.os.Bundle;
  import android.view.Menu;
  import android.view.View;
  import android.widget.ArrayAdapter;
  import android.widget.Button;
  import android.widget.RadioButton;
  import android.widget.Spinner;
  import android.support.v7.app.AppCompatActivity;
  import android.view.MenuItem;
  
  import java.util.ArrayList;
  
  
  public class NewGameActivity extends AppCompatActivity {
  
      public Spinner players, bestOf;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_new_game);
  
          players = (Spinner) findViewById(R.id.players);
          Integer[] items1 = new Integer[]{2, 3, 4, 5, 6, 7, 8, 9, 10};
          ArrayAdapter&lt;Integer&gt; adapter1 = new ArrayAdapter&lt;&gt;(this, android.R.layout.simple_spinner_item, items1);
          players.setAdapter(adapter1);
  
          bestOf = (Spinner) findViewById(R.id.bestOf);
          Integer[] items2 = new Integer[]{1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25};
          ArrayAdapter&lt;Integer&gt; adapter2 = new ArrayAdapter&lt;&gt;(this, android.R.layout.simple_spinner_item, items2);
          bestOf.setAdapter(adapter2);
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.menu_new_game, menu);
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. The action bar will
          // automatically handle clicks on the Home/Up button, so long
          // as you specify a parent activity in AndroidManifest.xml.
          int id = item.getItemId();
  
          //noinspection SimplifiableIfStatement
          if (id == R.id.action_settings) {
              return true;
          }
  
          return super.onOptionsItemSelected(item);
      }
  
      public void sendMessageStart(View view) {
  
  
          final RadioButton sign3 = (RadioButton) findViewById(R.id.radio3);
          final RadioButton sign5 = (RadioButton) findViewById(R.id.radio5);
  
          Button start = (Button) findViewById(R.id.startButton);
  
          start.setOnClickListener(new View.OnClickListener() {
  
              //int playerNum = Integer.valueOf(players.getSelectedItem().toString());
              //int games = Integer.valueOf(bestOf.getSelectedItem().toString());
              @Override
              public void onClick(View v) {
  
                  ArrayList&lt;Integer&gt; players = new ArrayList&lt;&gt;();
                  Bundle bundle = new Bundle();
                  bundle.putInt("newPlayerNum", 1);
                  bundle.putInt("numOfPlayers", 2);
                  bundle.putInt("games", 1);
                  bundle.putIntegerArrayList("players", players);
  
                  if (sign3.isChecked()) {
                      Intent intentBundle = new Intent(NewGameActivity.this, ThreeSignGameActivity.class);
                      intentBundle.putExtras(bundle);
                      startActivity(intentBundle);
                  }
                  else if (sign5.isChecked()) {
                      Intent intentBundle = new Intent(NewGameActivity.this, FiveSignGameActivity.class);
                      intentBundle.putExtras(bundle);
                      startActivity(intentBundle);
                  }
              }
          });
      }
  }
  </code></pre>
  
  <p>XML:</p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
      android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      android:paddingBottom="@dimen/activity_vertical_margin"
      tools:context="name.zerosum.NewGameActivity"
      android:background="#0169B2"&gt;
  
      &lt;TextView
          android:layout_width="200dp"
          android:layout_height="wrap_content"
          android:textAppearance="?android:attr/textAppearanceLarge"
          android:text="@string/newGamePlayers"
          android:id="@+id/textView4"
          android:layout_alignParentTop="true"
          android:layout_alignParentLeft="true"
          android:layout_alignParentStart="true"
          android:layout_marginLeft="20dp"
          android:layout_marginStart="20dp"
          android:layout_marginTop="30dp"
          android:textColor="#ffffff"
          android:textStyle="bold"
          android:typeface="sans"
          android:textSize="40sp"
          /&gt;
  
      &lt;Spinner
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:id="@+id/players"
          android:layout_alignTop="@+id/textView4"
          android:layout_toRightOf="@+id/textView4"
          android:layout_toEndOf="@+id/textView4"
          android:textColor="#ffffff"
          android:textStyle="bold"
          android:typeface="sans"/&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:textAppearance="?android:attr/textAppearanceLarge"
          android:text="@string/newGameStyle"
          android:id="@+id/textView6"
          android:layout_marginTop="60dp"
          android:textColor="#ffffff"
          android:textStyle="bold"
          android:typeface="sans"
          android:textSize="40sp"
          android:layout_below="@+id/textView4"
          android:layout_alignLeft="@+id/textView4"
          android:layout_alignStart="@+id/textView4" /&gt;
  
      &lt;RadioGroup xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:orientation="horizontal"
          android:layout_below="@+id/textView6"
          android:layout_centerHorizontal="true"
          android:checkedButton="@+id/radio3"
          android:id="@+id/group"&gt;
          &lt;RadioButton
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="@string/radio3"
              android:id="@+id/radio3"
              android:textColor="#ffffff"
              android:textStyle="bold"
              android:typeface="sans"
              android:textSize="20sp"/&gt;
  
          &lt;RadioButton
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="@string/radio5"
              android:id="@+id/radio5"
              android:textColor="#ffffff"
              android:textStyle="bold"
              android:typeface="sans"
              android:textSize="20sp" /&gt;
      &lt;/RadioGroup&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:textAppearance="?android:attr/textAppearanceLarge"
          android:text="@string/newGameBestOf"
          android:id="@+id/textView7"
          android:layout_below="@+id/textView6"
          android:layout_alignLeft="@+id/textView6"
          android:layout_alignStart="@+id/textView6"
          android:layout_marginTop="80dp"
          android:textColor="#ffffff"
          android:textStyle="bold"
          android:typeface="sans"
          android:textSize="40sp"/&gt;
  
      &lt;Spinner
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:id="@+id/bestOf"
          android:layout_alignTop="@+id/textView7"
          android:layout_toRightOf="@+id/textView7"
          android:layout_toEndOf="@+id/textView7"
          android:textColor="#ffffff"
          android:textStyle="bold"
          android:typeface="sans"
          /&gt;
  
      &lt;Button
          android:layout_width="match_parent"
          android:layout_height="100dp"
          android:text="@string/newGameButtonText"
          android:id="@+id/startButton"
          android:layout_alignParentBottom="true"
          android:layout_alignParentLeft="true"
          android:layout_alignParentStart="true"
          android:textColor="#ffffff"
          android:textStyle="bold"
          android:typeface="sans"
          android:textSize="30sp"
          android:onClick="sendMessageStart"/&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>New Activity Code:</p>
  
  <pre><code>package name.zerosum;
  
  import android.content.Intent;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  
  import java.util.ArrayList;
  import java.util.List;
  
  public class ThreeSignGameActivity extends AppCompatActivity {
  
      Bundle extras = getIntent().getExtras();
  
      ArrayList&lt;Integer&gt; players = extras.getIntegerArrayList("players");
      int currentPlayer = extras.getInt("newPlayerNum");
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_three_sign_game);
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.menu_three_sign_game, menu);
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. The action bar will
          // automatically handle clicks on the Home/Up button, so long
          // as you specify a parent activity in AndroidManifest.xml.
          int id = item.getItemId();
  
          //noinspection SimplifiableIfStatement
          if (id == R.id.action_settings) {
              return true;
          }
  
          return super.onOptionsItemSelected(item);
      }
  
      //rock = 1
      //paper = 2
      //scissors = 3
  
      public void storeRock(View view) {
          players.add(1);
          if(currentPlayer == 1) {
              playNextGame();
          }
          else {
              winner(players);
          }
      }
  
      public void storePaper(View view) {
          players.add(2);
          if(currentPlayer == 1) {
              playNextGame();
          }
          else {
              winner(players);
          }
      }
  
      public void storeScissors(View view) {
          players.add(3);
          if(currentPlayer == 1) {
              playNextGame();
          }
          else {
              winner(players);
          }
      }
  
      public void playNextGame() {
          Bundle bundle = new Bundle();
          bundle.putInt("newPlayerNum", currentPlayer + 1);
          bundle.putIntegerArrayList("players", players);
  
          Intent intent = new Intent(this, ThreeSignGameActivity.class);
          intent.putExtras(bundle);
          startActivity(intent);
      }
  
      public void winner(List&lt;Integer&gt; players) {
          int player1 = players.get(0);
          int player2 = players.get(1);
          //rock = 1
          //paper = 2
          //scissors = 3
          if (player1 == 1){
              if(player2 == 1){tie();}
              else if (player2 == 2) {results(2);}
              else if (player2 == 3) {results(1);}
          }
          else if (player1 == 2){
              if(player2 == 1) {results(1);}
              else if (player2 == 2) {tie();}
              else if (player2 == 3) {results(2);}
          }
          else if (player1 == 3){
              if(player2 == 1) {results(2);}
              else if (player2 == 2) {results(1);}
              else if (player2 == 3){tie();}
          }
      }
  
      public void results (int winner) {
          Bundle bundle = new Bundle();
          bundle.putInt("winner", winner);
  
          Intent intent = new Intent(this, ResultsScreenActivity.class);
          intent.putExtras(bundle);
          startActivity(intent);
      }
  
      public void tie () {
          Bundle bundle = new Bundle();
          bundle.putInt("newPlayerNum",1);
  
          Intent intent = new Intent(this, Tie3Activity.class);
          intent.putExtras(bundle);
          startActivity(intent);
      }
  }
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>10-17 18:29:57.706    8417-8417/name.zerosum E/AndroidRuntime﹕ FATAL EXCEPTION: main
      Process: name.zerosum, PID: 8417
      java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{name.zerosum/name.zerosum.ThreeSignGameActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.os.Bundle android.content.Intent.getExtras()' on a null object reference
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2322)
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2474)
              at android.app.ActivityThread.access$800(ActivityThread.java:144)
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1359)
              at android.os.Handler.dispatchMessage(Handler.java:102)
              at android.os.Looper.loop(Looper.java:155)
              at android.app.ActivityThread.main(ActivityThread.java:5696)
              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:1028)
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)
       Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.os.Bundle android.content.Intent.getExtras()' on a null object reference
              at name.zerosum.ThreeSignGameActivity.&lt;init&gt;(ThreeSignGameActivity.java:17)
              at java.lang.reflect.Constructor.newInstance(Native Method)
              at java.lang.Class.newInstance(Class.java:1572)
              at android.app.Instrumentation.newActivity(Instrumentation.java:1083)
              at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2312)
              at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2474)
              at android.app.ActivityThread.access$800(ActivityThread.java:144)
              at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1359)
              at android.os.Handler.dispatchMessage(Handler.java:102)
              at android.os.Looper.loop(Looper.java:155)
              at android.app.ActivityThread.main(ActivityThread.java:5696)
              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:1028)
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)
  </code></pre>