java - App throwing NullException error when Initializng variables -

currently app pulling database information , populating listview held within tabview, app force closes before can run.

the problem appears lie when initializing variables.

below the oncreate class , intializevariables method logcat showing error:

protected void oncreate(bundle savedinstancestate) {          // set activity full screen!!         requestwindowfeature(window.feature_no_title);         getwindow().setflags(windowmanager.layoutparams.flag_fullscreen,                 windowmanager.layoutparams.flag_fullscreen);         // todo auto-generated method stub         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          th = (tabhost) findviewbyid(r.id.tabhost);          th.setup();         tabspec specs = th.newtabspec("tag1");         // 1 tab         specs.setcontent(r.id.tab1);         // appears on actual tab         specs.setindicator("tools");         th.addtab(specs);         specs = th.newtabspec("tag2");         // 1 tab         specs.setcontent(r.id.tab2);         // appears on actual tab         specs.setindicator("calorie calculator");         th.addtab(specs);         specs = th.newtabspec("tag3");         // 1 tab         specs.setcontent(r.id.tab3);         // appears on actual tab         specs.setindicator("your stats!");         th.addtab(specs);          initializevariables();         statlistview = getlistview();         statlistview.setonitemclicklistener(statviewlistener);          // map each name textview         string[] = new string[] { "name" };         int[] = new int[] { r.id.tvstatistics };         statadapter = new simplecursoradapter(mainactivity.this,                 r.layout.stat_list, null, from, to);         setlistadapter(statadapter); // set adapter          arrayadapter<charsequence> adapter = arrayadapter.createfromresource(                 this, r.array.spinactmultarray,                 android.r.layout.simple_spinner_item);         adapter.setdropdownviewresource(android.r.layout.simple_spinner_dropdown_item);         spinactmult.setadapter(adapter);         spinactmult.setonitemselectedlistener(new spinactmultfunction());      }      private void initializevariables() {         spinactmult = (spinner) findviewbyid(r.id.spinactivitymultipler);         activitymultiplier = (textview) findviewbyid(r.id.tvactmult);         maintcalories = (textview) findviewbyid(r.id.tvmaintlevel);         calccalories = (button) findviewbyid(r.id.btncalccalories);         goalpicker = (radiogroup) findviewbyid(r.id.rggoalpicker);         calorieresult = (textview) findviewbyid(r.id.tvcalresults);         lbmresult = (textview) findviewbyid(r.id.tvlbmresult);         bmrresult = (textview) findviewbyid(r.id.tvbmrresult);         etweight = (edittext) findviewbyid(r.id.etwinput);         weightint = etweight.gettext().tostring();         etbodyfat = (edittext) findviewbyid(r.id.etbfinput);         bodyfatint = etbodyfat.gettext().tostring();         goalpicker.setoncheckedchangelistener(this);         calccalories.setonclicklistener(this);          stopwatchactivity = (button) findviewbyid(r.id.btnstopwatchactivity);         maparun = (button) findviewbyid(r.id.btnmaparun);         weightconverter = (button) findviewbyid(r.id.btnweightconverter);          maparun.setonclicklistener(this);         weightconverter.setonclicklistener(this);         stopwatchactivity.setonclicklistener(this);         updatedb.setonclicklistener(this);         viewdb.setonclicklistener(this);      } 

and logcat:

05-10 03:41:52.687: e/androidruntime(5974): fatal exception: main 05-10 03:41:52.687: e/androidruntime(5974): java.lang.runtimeexception: unable start activity componentinfo{com.uhi.fatfighter/com.uhi.fatfighter.mainactivity}: java.lang.nullpointerexception 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.activitythread.performlaunchactivity(activitythread.java:2185) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.activitythread.handlelaunchactivity(activitythread.java:2210) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.activitythread.access$600(activitythread.java:142) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.activitythread$h.handlemessage(activitythread.java:1208) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.os.handler.dispatchmessage(handler.java:99) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.os.looper.loop(looper.java:137) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.activitythread.main(activitythread.java:4928) 05-10 03:41:52.687: e/androidruntime(5974):     @ java.lang.reflect.method.invokenative(native method) 05-10 03:41:52.687: e/androidruntime(5974):     @ java.lang.reflect.method.invoke(method.java:511) 05-10 03:41:52.687: e/androidruntime(5974):     @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:791) 05-10 03:41:52.687: e/androidruntime(5974):     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:558) 05-10 03:41:52.687: e/androidruntime(5974):     @ dalvik.system.nativestart.main(native method) 05-10 03:41:52.687: e/androidruntime(5974): caused by: java.lang.nullpointerexception 05-10 03:41:52.687: e/androidruntime(5974):     @ com.uhi.fatfighter.mainactivity.initializevariables(mainactivity.java:129) 05-10 03:41:52.687: e/androidruntime(5974):     @ com.uhi.fatfighter.mainactivity.oncreate(mainactivity.java:86) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.activity.performcreate(activity.java:5008) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1079) 05-10 03:41:52.687: e/androidruntime(5974):     @ android.app.activitythread.performlaunchactivity(activitythread.java:2139) 05-10 03:41:52.687: e/androidruntime(5974):     ... 11 more 

in here:

    updatedb.setonclicklistener(this); //<<<<     viewdb.setonclicklistener(this);   //<<<< 

you forget initialize updatedb , viewdb instances before using inside initializevariables() method