title: java.lang.RuntimeException unable to instantiate service: java.lang.NullPointerException
body: <p>I was trying to create an activity that start a service (in a new thread). It consists in a layout with two editText and a button called Send. The point is that when I execute the MainActivity, it throws that:</p>
  
  <pre><code>06-15 22:32:13.312: E/AndroidRuntime(643): FATAL EXCEPTION: main
  06-15 22:32:13.312: E/AndroidRuntime(643): java.lang.RuntimeException: Unable to instantiate service hikoki.services.NotificationsService: java.lang.NullPointerException
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.app.ActivityThread.handleCreateService(ActivityThread.java:2237)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.app.ActivityThread.access$1600(ActivityThread.java:123)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1201)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.os.Handler.dispatchMessage(Handler.java:99)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.os.Looper.loop(Looper.java:137)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.app.ActivityThread.main(ActivityThread.java:4424)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at java.lang.reflect.Method.invokeNative(Native Method)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at java.lang.reflect.Method.invoke(Method.java:511)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at dalvik.system.NativeStart.main(Native Method)
  06-15 22:32:13.312: E/AndroidRuntime(643): Caused by: java.lang.NullPointerException
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.content.ContextWrapper.getSystemService(ContextWrapper.java:386)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at hikoki.services.NotificationsService.&lt;init&gt;(NotificationsService.java:35)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at java.lang.Class.newInstanceImpl(Native Method)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at java.lang.Class.newInstance(Class.java:1319)
  06-15 22:32:13.312: E/AndroidRuntime(643):  at android.app.ActivityThread.handleCreateService(ActivityThread.java:2234)
  06-15 22:32:13.312: E/AndroidRuntime(643):  ... 10 more
  </code></pre>
  
  <p>The code of Main Activity is this:</p>
  
  <pre><code>public class MainActivity extends Activity {
      private String TAG = getClass().getSimpleName();
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          Thread t= new Thread(){
              public void run(){
                  Intent intent=new Intent(getContext(),NotificationsService.class);
                  //Intent intent=new Intent("hikoki.services.NotificationsService");
                  Log.d(TAG,"sending notificationsService");
                  startService(intent);
              }
          };
          t.start();
      }
  
      protected Context getContext() {    
          return this;
      }
  }
  </code></pre>
  
  <p>An the code od NotificationsService is here:</p>
  
  <pre><code>public class NotificationsService extends IntentService{
      private static  int TIME_INTERVAL_MILIS=5000;
      private static final int REFRESH=10;
      private  NotificationManager noteManager;
      private static List&lt;FlightStatusNote&gt; flights= new ArrayList&lt;FlightStatusNote&gt;();
  
      public NotificationsService(){
          super("NotificationsService"); 
          noteManager= NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE)
      }
  }
  </code></pre>
  
  <p>and the AndroidManifest is this:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="hikoki.services"
      android:versionCode="1"
      android:versionName="1.0" &gt;
  
  &lt;uses-sdk
      android:minSdkVersion="15"
      android:targetSdkVersion="17" /&gt;
  &lt;uses-permission android:name="android.permission.INTERNET" /&gt;
  &lt;uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /&gt;
  &lt;application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" &gt;
      &lt;activity
          android:name="hikoki.services.MainActivity"
          android:label="@string/app_name" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
      &lt;service android:name=".FlightStatusService"&gt;&lt;/service&gt;
      &lt;service android:enabled="true" android:name=".NotificationsService"&gt;&lt;/service&gt;
  &lt;/application&gt;
  
  &lt;/manifest&gt;
  </code></pre>