slider - Nullpointer exception for AndroidImageSlider DefaultSliderView In Android Studio, Build 22.0.1 -

this stack trace :

08-16 10:23:40.006  19022-19022/com.world.innov.ebilling     e/androidruntime﹕ fatal exception: main process: com.world.innov.ebilling, pid: 19022 java.lang.runtimeexception: unable start activity componentinfo{com.world.innov.ebilling/com.world.innov.ebilling.mainactivity}: java.lang.nullpointerexception: attempt invoke virtual method 'void android.os.bundle.putstring(java.lang.string, java.lang.string)' on null object reference     @ android.app.activitythread.performlaunchactivity(activitythread.java:2325)     @ android.app.activitythread.handlelaunchactivity(activitythread.java:2390)     @ android.app.activitythread.access$800(activitythread.java:151)     @ android.app.activitythread$h.handlemessage(activitythread.java:1303)     @ android.os.handler.dispatchmessage(handler.java:102)     @ android.os.looper.loop(looper.java:135)     @ android.app.activitythread.main(activitythread.java:5257)     @ java.lang.reflect.method.invoke(native method)     @ java.lang.reflect.method.invoke(method.java:372)     @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903)     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:698) caused by: java.lang.nullpointerexception: attempt invoke virtual method 'void android.os.bundle.putstring(java.lang.string, java.lang.string)' on null object reference     @ com.world.innov.ebilling.mainactivity.oncreate(mainactivity.java:52)     @ android.app.activity.performcreate(activity.java:5990)     @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1106)     @ android.app.activitythread.performlaunchactivity(activitythread.java:2278)     @ android.app.activitythread.handlelaunchactivity(activitythread.java:2390)          at android.app.activitythread.access$800(activitythread.java:151)     @ android.app.activitythread$h.handlemessage(activitythread.java:1303)     @ android.os.handler.dispatchmessage(handler.java:102)     @ android.os.looper.loop(looper.java:135)     @ android.app.activitythread.main(activitythread.java:5257)     @ java.lang.reflect.method.invoke(native method)     @ java.lang.reflect.method.invoke(method.java:372)     @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903)     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:698) 

this activity :

import java.util.hashmap; import com.daimajia.slider.library.sliderlayout; import com.daimajia.slider.library.slidertypes.basesliderview; import com.daimajia.slider.library.slidertypes.basesliderview.onsliderclicklistener; import com.daimajia.slider.library.slidertypes.defaultsliderview;   import android.app.activity; import android.content.intent; import android.content.sharedpreferences; import android.content.sharedpreferences.editor; import android.os.bundle; import android.view.menu; import android.view.menuitem; import android.view.view; import android.view.window; import android.widget.button;   public class mainactivity extends activity implements onsliderclicklistener { public static final string my_prefs_name = "myprefsfile"; private sliderlayout mdemoslider;  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     requestwindowfeature(window.feature_no_title);     setcontentview(r.layout.activity_main);       mdemoslider = (sliderlayout) findviewbyid(r.id.slider);      hashmap<string, integer> file_maps = new hashmap<string, integer>();      file_maps.put("a", r.drawable.invoicebyhand);     file_maps.put("b", r.drawable.invoicebymobile);     file_maps.put("c", r.drawable.analysis);      (string name : file_maps.keyset()) {         defaultsliderview defaultsliderview = new defaultsliderview(this);         // initialize sliderlayout         defaultsliderview                 .description(name)                 .image(file_maps.get(name))                 .setscaletype(basesliderview.scaletype.fit)                 .setonsliderclicklistener(this);          //add information         defaultsliderview.getbundle()                 .putstring("extra", name);          mdemoslider.addslider(defaultsliderview);     }             mdemoslider.setpresettransformer(sliderlayout.transformer.rotateup);     mdemoslider.setpresetindicator(sliderlayout.presetindicators.center_bottom);     mdemoslider.stopautocycle();       sharedpreferences prefs = getsharedpreferences(my_prefs_name, mode_private);     string pin = prefs.getstring("pin", "");      if (pin.equals("")) {         disableletsgo();         intent = new intent(this, tocactivity.class);         startactivity(i);     } else {         disablesignup();     }  }  @override public void onsliderclick(basesliderview slider) {     // todo auto-generated method stub  } } 

my question "can see why getting null pointer exception @ line 52 guess defaultsliderview"?

line 52 : defaultsliderview.getbundle()                 .putstring("extra", name); 

i using android studio 22.0.1 buildtoolversion. did not face problem while doing project on eclipse. first time using android studio. migrated project success , getting run time exception. using androidimageslider daimajia.

update: defaultsliderview returning null bundle(thanks @hariram). how should proceed or there replace bundle ?

update2: removed line 52. working.

defaultsliderview.getbundle()

is returning null here trying put values in null bundle. because of app crashing.

defaultsliderview.getbundle() .putstring("extra", name);

removing line not making bad effect on app should remove it.