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POIs it possible to initialize object which is extend to class Activity
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copied!<p>I have main activity which call other object, for example GPS class. This GPS class extends Activiy class. </p> <p>snapshot main activity:</p> <pre><code>public class MemoPosition extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); GPS GPSnode = new GPS(); if (!GPSnode.isGPSenabled()){ createGpsDisabledAlert(); } } private void createGpsDisabledAlert(){ } } </code></pre> <p>snapshot GPS class:</p> <pre><code>public class GPS extends Activity{ private Double latitude; private Double longitude; private LocationManager locationManager; public void GPS(){ // Construction String context = Context.LOCATION_SERVICE; locationManager = (LocationManager)getSystemService(context); if (isGPSenabled()){ // do something } } </code></pre> <p>I've also put the GPS class to manifest as part of Activity apps. Running the code, and fatal error Force close. Logcat:</p> <pre><code>12-24 22:51:32.270: ERROR/AndroidRuntime(5558): FATAL EXCEPTION: main 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dromdev.project.memoposition/com.dromdev.project.memoposition.MemoPosition}: java.lang.NullPointerException 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.os.Handler.dispatchMessage(Handler.java:99) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.os.Looper.loop(Looper.java:123) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.app.ActivityThread.main(ActivityThread.java:4627) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at java.lang.reflect.Method.invokeNative(Native Method) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at java.lang.reflect.Method.invoke(Method.java:521) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:876) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:634) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at dalvik.system.NativeStart.main(Native Method) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): Caused by: java.lang.NullPointerException 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at com.dromdev.project.memoposition.GPS.isGPSenabled(GPS.java:48) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at com.dromdev.project.memoposition.MemoPosition.onCreate(MemoPosition.java:23) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 12-24 22:51:32.270: ERROR/AndroidRuntime(5558): ... 11 more </code></pre> <p>I'm curious if class which inherit activity class couldn't be initialized as normal Activity. Should it be called by Intent ? I just need GPS class as object which responsible to GPS functionality, however it's required to extend Activity for some context. Please advice.</p>

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