android - Null pointer exception for PageViewer in onTabSelected method of tab listener of action bar tabs -

android - Null pointer exception for PageViewer in onTabSelected method of tab listener of action bar tabs -

package com.example.swipetabs; import android.annotation.suppresslint; import android.app.actionbar; import android.app.actionbar.tab; import android.app.actionbar.tablistener; import android.app.fragmenttransaction; import android.os.bundle; import android.support.v4.app.fragment; import android.support.v4.app.fragmentactivity; import android.support.v4.app.fragmentmanager; import android.support.v4.app.fragmentstatepageradapter; import android.support.v4.view.viewpager; import android.support.v4.view.viewpager.onpagechangelistener; import android.view.window; @suppresslint("newapi") public class mainactivity extends fragmentactivity implements tablistener { viewpager page; @suppresslint("newapi") @override protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); getwindow().requestfeature(window.feature_action_bar); setcontentview(r.layout.activity_main); final actionbar actionbar=getactionbar(); actionbar.setnavigationmode(actionbar.navigation_mode_tabs); tab tab1=actionbar.newtab(); tab tab2=actionbar.newtab(); tab tab3=actionbar.newtab(); tab1.settablistener(this); tab2.settablistener(this); tab3.settablistener(this); tab1.settext("sparta1"); tab2.settext("sparta2"); tab3.settext("sparta3"); actionbar.addtab(tab1); actionbar.addtab(tab2); actionbar.addtab(tab3); page=new viewpager(this); page=(viewpager)findviewbyid(r.id.pager); fragmentmanager manager=getsupportfragmentmanager(); myfragmentstatepageradapter pageradapter=new myfragmentstatepageradapter(manager); page.setadapter(pageradapter); page.setonpagechangelistener(new onpagechangelistener() { @override public void onpageselected(int arg0) { actionbar.setselectednavigationitem(arg0); } @override public void onpagescrolled(int arg0, float arg1, int arg2) { // todo auto-generated method stub } @override public void onpagescrollstatechanged(int arg0) { // todo auto-generated method stub } }); //page.setcurrentitem(2); } @override public void ontabselected(tab tab, fragmenttransaction ft) { page.setcurrentitem(tab.getposition()); } @override public void ontabunselected(tab tab, fragmenttransaction ft) { } @override public void ontabreselected(tab tab, fragmenttransaction ft) { // todo auto-generated method stub } class myfragmentstatepageradapter extends fragmentstatepageradapter{ public myfragmentstatepageradapter(fragmentmanager fm) { super(fm); // todo auto-generated constructor stub } @override public fragment getitem(int arg0) { fragment fragment=null; if(arg0==0){ fragment=new fragmenta(); } if(arg0==1){ fragment=new fragmentb(); } if(arg0==2){ fragment=new fragmentc(); } homecoming fragment; } @override public int getcount() { homecoming 3; } } } public void ontabselected(tab tab, fragmenttransaction ft) { page.setcurrentitem(tab.getposition()); }

the above page.setcurrentitem(tab.getposition()) returning null exception.i couldn't figure out problem.i hope 1 able figure out. error log

10-18 16:04:15.496: d/androidruntime(1794): shutting downwards vm 10-18 16:04:15.496: w/dalvikvm(1794): threadid=1: thread exiting uncaught exception (group=0x41c18ba8) 10-18 16:04:15.496: e/androidruntime(1794): fatal exception: main 10-18 16:04:15.496: e/androidruntime(1794): process: com.example.swipetabs, pid: 1794 10-18 16:04:15.496: e/androidruntime(1794): java.lang.runtimeexception: unable start activity componentinfo{com.example.swipetabs/com.example.swipetabs.mainactivity}: java.lang.nullpointerexception 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.activitythread.performlaunchactivity(activitythread.java:2184) 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.activitythread.handlelaunchactivity(activitythread.java:2233) 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.activitythread.access$800(activitythread.java:135) 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.activitythread$h.handlemessage(activitythread.java:1196) 10-18 16:04:15.496: e/androidruntime(1794): @ android.os.handler.dispatchmessage(handler.java:102) 10-18 16:04:15.496: e/androidruntime(1794): @ android.os.looper.loop(looper.java:136) 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.activitythread.main(activitythread.java:5001) 10-18 16:04:15.496: e/androidruntime(1794): @ java.lang.reflect.method.invokenative(native method) 10-18 16:04:15.496: e/androidruntime(1794): @ java.lang.reflect.method.invoke(method.java:515) 10-18 16:04:15.496: e/androidruntime(1794): @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:785) 10-18 16:04:15.496: e/androidruntime(1794): @ com.android.internal.os.zygoteinit.main(zygoteinit.java:601) 10-18 16:04:15.496: e/androidruntime(1794): @ dalvik.system.nativestart.main(native method) 10-18 16:04:15.496: e/androidruntime(1794): caused by: java.lang.nullpointerexception 10-18 16:04:15.496: e/androidruntime(1794): @ com.example.swipetabs.mainactivity.ontabselected(mainactivity.java:68) 10-18 16:04:15.496: e/androidruntime(1794): @ com.android.internal.app.actionbarimpl.selecttab(actionbarimpl.java:577) 10-18 16:04:15.496: e/androidruntime(1794): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:506) 10-18 16:04:15.496: e/androidruntime(1794): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:492) 10-18 16:04:15.496: e/androidruntime(1794): @ com.example.swipetabs.mainactivity.oncreate(mainactivity.java:33) 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.activity.performcreate(activity.java:5231) 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1087) 10-18 16:04:15.496: e/androidruntime(1794): @ android.app.activitythread.performlaunchactivity(activitythread.java:2148) 10-18 16:04:15.496: e/androidruntime(1794): ... 11 more 10-18 16:05:24.880: i/adreno-egl(1966): <qegldrvapi_eglinitialize:320>: egl 1.4 qualcomm build: i0404c4692afb8623f95c43aeb6d5e13ed4b30ddbdate: 11/06/13 10-18 16:05:24.931: d/openglrenderer(1966): enabling debug mode 0 10-18 16:08:35.814: d/dalvikvm(1966): gc_for_alloc freed 207k, 3% free 9291k/9528k, paused 16ms, total 16ms 10-18 16:08:47.997: i/adreno-egl(2310): <qegldrvapi_eglinitialize:320>: egl 1.4 qualcomm build: i0404c4692afb8623f95c43aeb6d5e13ed4b30ddbdate: 11/06/13 10-18 16:08:48.037: d/openglrenderer(2310): enabling debug mode 0 10-18 16:09:41.394: d/androidruntime(2457): shutting downwards vm 10-18 16:09:41.394: w/dalvikvm(2457): threadid=1: thread exiting uncaught exception (group=0x41c18ba8) 10-18 16:09:41.394: e/androidruntime(2457): fatal exception: main 10-18 16:09:41.394: e/androidruntime(2457): process: com.example.swipetabs, pid: 2457 10-18 16:09:41.394: e/androidruntime(2457): java.lang.runtimeexception: unable start activity componentinfo{com.example.swipetabs/com.example.swipetabs.mainactivity}: java.lang.nullpointerexception 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.activitythread.performlaunchactivity(activitythread.java:2184) 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.activitythread.handlelaunchactivity(activitythread.java:2233) 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.activitythread.access$800(activitythread.java:135) 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.activitythread$h.handlemessage(activitythread.java:1196) 10-18 16:09:41.394: e/androidruntime(2457): @ android.os.handler.dispatchmessage(handler.java:102) 10-18 16:09:41.394: e/androidruntime(2457): @ android.os.looper.loop(looper.java:136) 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.activitythread.main(activitythread.java:5001) 10-18 16:09:41.394: e/androidruntime(2457): @ java.lang.reflect.method.invokenative(native method) 10-18 16:09:41.394: e/androidruntime(2457): @ java.lang.reflect.method.invoke(method.java:515) 10-18 16:09:41.394: e/androidruntime(2457): @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:785) 10-18 16:09:41.394: e/androidruntime(2457): @ com.android.internal.os.zygoteinit.main(zygoteinit.java:601) 10-18 16:09:41.394: e/androidruntime(2457): @ dalvik.system.nativestart.main(native method) 10-18 16:09:41.394: e/androidruntime(2457): caused by: java.lang.nullpointerexception 10-18 16:09:41.394: e/androidruntime(2457): @ com.example.swipetabs.mainactivity.ontabselected(mainactivity.java:66) 10-18 16:09:41.394: e/androidruntime(2457): @ com.android.internal.app.actionbarimpl.selecttab(actionbarimpl.java:577) 10-18 16:09:41.394: e/androidruntime(2457): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:506) 10-18 16:09:41.394: e/androidruntime(2457): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:492) 10-18 16:09:41.394: e/androidruntime(2457): @ com.example.swipetabs.mainactivity.oncreate(mainactivity.java:33) 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.activity.performcreate(activity.java:5231) 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1087) 10-18 16:09:41.394: e/androidruntime(2457): @ android.app.activitythread.performlaunchactivity(activitythread.java:2148) 10-18 16:09:41.394: e/androidruntime(2457): ... 11 more 10-18 16:11:01.960: i/adreno-egl(2680): <qegldrvapi_eglinitialize:320>: egl 1.4 qualcomm build: i0404c4692afb8623f95c43aeb6d5e13ed4b30ddbdate: 11/06/13 10-18 16:11:01.990: d/openglrenderer(2680): enabling debug mode 0 10-18 16:12:30.865: d/androidruntime(3006): shutting downwards vm 10-18 16:12:30.865: w/dalvikvm(3006): threadid=1: thread exiting uncaught exception (group=0x41c18ba8) 10-18 16:12:30.865: e/androidruntime(3006): fatal exception: main 10-18 16:12:30.865: e/androidruntime(3006): process: com.example.swipetabs, pid: 3006 10-18 16:12:30.865: e/androidruntime(3006): java.lang.runtimeexception: unable start activity componentinfo{com.example.swipetabs/com.example.swipetabs.mainactivity}: java.lang.nullpointerexception 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.activitythread.performlaunchactivity(activitythread.java:2184) 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.activitythread.handlelaunchactivity(activitythread.java:2233) 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.activitythread.access$800(activitythread.java:135) 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.activitythread$h.handlemessage(activitythread.java:1196) 10-18 16:12:30.865: e/androidruntime(3006): @ android.os.handler.dispatchmessage(handler.java:102) 10-18 16:12:30.865: e/androidruntime(3006): @ android.os.looper.loop(looper.java:136) 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.activitythread.main(activitythread.java:5001) 10-18 16:12:30.865: e/androidruntime(3006): @ java.lang.reflect.method.invokenative(native method) 10-18 16:12:30.865: e/androidruntime(3006): @ java.lang.reflect.method.invoke(method.java:515) 10-18 16:12:30.865: e/androidruntime(3006): @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:785) 10-18 16:12:30.865: e/androidruntime(3006): @ com.android.internal.os.zygoteinit.main(zygoteinit.java:601) 10-18 16:12:30.865: e/androidruntime(3006): @ dalvik.system.nativestart.main(native method) 10-18 16:12:30.865: e/androidruntime(3006): caused by: java.lang.nullpointerexception 10-18 16:12:30.865: e/androidruntime(3006): @ com.example.swipetabs.mainactivity.ontabselected(mainactivity.java:67) 10-18 16:12:30.865: e/androidruntime(3006): @ com.android.internal.app.actionbarimpl.selecttab(actionbarimpl.java:577) 10-18 16:12:30.865: e/androidruntime(3006): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:506) 10-18 16:12:30.865: e/androidruntime(3006): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:492) 10-18 16:12:30.865: e/androidruntime(3006): @ com.example.swipetabs.mainactivity.oncreate(mainactivity.java:33) 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.activity.performcreate(activity.java:5231) 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1087) 10-18 16:12:30.865: e/androidruntime(3006): @ android.app.activitythread.performlaunchactivity(activitythread.java:2148) 10-18 16:12:30.865: e/androidruntime(3006): ... 11 more 10-18 16:21:28.038: d/androidruntime(3720): shutting downwards vm 10-18 16:21:28.038: w/dalvikvm(3720): threadid=1: thread exiting uncaught exception (group=0x41c18ba8) 10-18 16:21:28.038: e/androidruntime(3720): fatal exception: main 10-18 16:21:28.038: e/androidruntime(3720): process: com.example.swipetabs, pid: 3720 10-18 16:21:28.038: e/androidruntime(3720): java.lang.runtimeexception: unable start activity componentinfo{com.example.swipetabs/com.example.swipetabs.mainactivity}: java.lang.nullpointerexception 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.activitythread.performlaunchactivity(activitythread.java:2184) 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.activitythread.handlelaunchactivity(activitythread.java:2233) 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.activitythread.access$800(activitythread.java:135) 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.activitythread$h.handlemessage(activitythread.java:1196) 10-18 16:21:28.038: e/androidruntime(3720): @ android.os.handler.dispatchmessage(handler.java:102) 10-18 16:21:28.038: e/androidruntime(3720): @ android.os.looper.loop(looper.java:136) 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.activitythread.main(activitythread.java:5001) 10-18 16:21:28.038: e/androidruntime(3720): @ java.lang.reflect.method.invokenative(native method) 10-18 16:21:28.038: e/androidruntime(3720): @ java.lang.reflect.method.invoke(method.java:515) 10-18 16:21:28.038: e/androidruntime(3720): @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:785) 10-18 16:21:28.038: e/androidruntime(3720): @ com.android.internal.os.zygoteinit.main(zygoteinit.java:601) 10-18 16:21:28.038: e/androidruntime(3720): @ dalvik.system.nativestart.main(native method) 10-18 16:21:28.038: e/androidruntime(3720): caused by: java.lang.nullpointerexception 10-18 16:21:28.038: e/androidruntime(3720): @ com.example.swipetabs.mainactivity.ontabselected(mainactivity.java:67) 10-18 16:21:28.038: e/androidruntime(3720): @ com.android.internal.app.actionbarimpl.selecttab(actionbarimpl.java:577) 10-18 16:21:28.038: e/androidruntime(3720): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:506) 10-18 16:21:28.038: e/androidruntime(3720): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:492) 10-18 16:21:28.038: e/androidruntime(3720): @ com.example.swipetabs.mainactivity.oncreate(mainactivity.java:33) 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.activity.performcreate(activity.java:5231) 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1087) 10-18 16:21:28.038: e/androidruntime(3720): @ android.app.activitythread.performlaunchactivity(activitythread.java:2148) 10-18 16:21:28.038: e/androidruntime(3720): ... 11 more 10-18 16:24:39.042: i/adreno-egl(3964): <qegldrvapi_eglinitialize:320>: egl 1.4 qualcomm build: i0404c4692afb8623f95c43aeb6d5e13ed4b30ddbdate: 11/06/13 10-18 16:24:39.072: d/openglrenderer(3964): enabling debug mode 0 10-18 16:24:49.854: d/dalvikvm(3964): gc_for_alloc freed 211k, 3% free 9287k/9528k, paused 17ms, total 17ms 10-18 16:29:09.851: i/adreno-egl(4899): <qegldrvapi_eglinitialize:320>: egl 1.4 qualcomm build: i0404c4692afb8623f95c43aeb6d5e13ed4b30ddbdate: 11/06/13 10-18 16:29:09.881: d/openglrenderer(4899): enabling debug mode 0 10-18 16:37:17.882: d/androidruntime(5785): shutting downwards vm 10-18 16:37:17.882: w/dalvikvm(5785): threadid=1: thread exiting uncaught exception (group=0x41c18ba8) 10-18 16:37:17.882: e/androidruntime(5785): fatal exception: main 10-18 16:37:17.882: e/androidruntime(5785): process: com.example.swipetabs, pid: 5785 10-18 16:37:17.882: e/androidruntime(5785): java.lang.runtimeexception: unable start activity componentinfo{com.example.swipetabs/com.example.swipetabs.mainactivity}: java.lang.nullpointerexception 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.activitythread.performlaunchactivity(activitythread.java:2184) 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.activitythread.handlelaunchactivity(activitythread.java:2233) 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.activitythread.access$800(activitythread.java:135) 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.activitythread$h.handlemessage(activitythread.java:1196) 10-18 16:37:17.882: e/androidruntime(5785): @ android.os.handler.dispatchmessage(handler.java:102) 10-18 16:37:17.882: e/androidruntime(5785): @ android.os.looper.loop(looper.java:136) 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.activitythread.main(activitythread.java:5001) 10-18 16:37:17.882: e/androidruntime(5785): @ java.lang.reflect.method.invokenative(native method) 10-18 16:37:17.882: e/androidruntime(5785): @ java.lang.reflect.method.invoke(method.java:515) 10-18 16:37:17.882: e/androidruntime(5785): @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:785) 10-18 16:37:17.882: e/androidruntime(5785): @ com.android.internal.os.zygoteinit.main(zygoteinit.java:601) 10-18 16:37:17.882: e/androidruntime(5785): @ dalvik.system.nativestart.main(native method) 10-18 16:37:17.882: e/androidruntime(5785): caused by: java.lang.nullpointerexception 10-18 16:37:17.882: e/androidruntime(5785): @ com.example.swipetabs.mainactivity.ontabselected(mainactivity.java:71) 10-18 16:37:17.882: e/androidruntime(5785): @ com.android.internal.app.actionbarimpl.selecttab(actionbarimpl.java:577) 10-18 16:37:17.882: e/androidruntime(5785): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:506) 10-18 16:37:17.882: e/androidruntime(5785): @ com.android.internal.app.actionbarimpl.addtab(actionbarimpl.java:492) 10-18 16:37:17.882: e/androidruntime(5785): @ com.example.swipetabs.mainactivity.oncreate(mainactivity.java:36) 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.activity.performcreate(activity.java:5231) 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1087) 10-18 16:37:17.882: e/androidruntime(5785): @ android.app.activitythread.performlaunchactivity(activitythread.java:2148) 10-18 16:37:17.882: e/androidruntime(5785): ... 11 more

thanks in advance :)

android android-actionbar android-tabs