android - Unable to instantiate main activity - ClassNotFound -

i cannot open application. far remember, appeared first time when created new class (now deleted). error occurs if delete below //referencje , part of layout related them. name of class edited, used work after that.

09-12 18:56:25.512: e/androidruntime(616): fatal exception: main 09-12 18:56:25.512: e/androidruntime(616): java.lang.runtimeexception: unable instantiate activity componentinfo{com.example.test2/com.example.test2.activity_main}: java.lang.classnotfoundexception: com.example.test2.activity_main 09-12 18:56:25.512: e/androidruntime(616):  @ android.app.activitythread.performlaunchactivity(activitythread.java:1983) 09-12 18:56:25.512: e/androidruntime(616):  @ android.app.activitythread.handlelaunchactivity(activitythread.java:2084) 09-12 18:56:25.512: e/androidruntime(616):  @ android.app.activitythread.access$600(activitythread.java:130) 09-12 18:56:25.512: e/androidruntime(616):  @ android.app.activitythread$h.handlemessage(activitythread.java:1195) 09-12 18:56:25.512: e/androidruntime(616):  @ android.os.handler.dispatchmessage(handler.java:99) 09-12 18:56:25.512: e/androidruntime(616):  @ android.os.looper.loop(looper.java:137) 09-12 18:56:25.512: e/androidruntime(616):  @ android.app.activitythread.main(activitythread.java:4745) 09-12 18:56:25.512: e/androidruntime(616):  @ java.lang.reflect.method.invokenative(native method) 09-12 18:56:25.512: e/androidruntime(616):  @ java.lang.reflect.method.invoke(method.java:511) 09-12 18:56:25.512: e/androidruntime(616):  @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:786) 09-12 18:56:25.512: e/androidruntime(616):  @ com.android.internal.os.zygoteinit.main(zygoteinit.java:553) 09-12 18:56:25.512: e/androidruntime(616):  @ dalvik.system.nativestart.main(native method) 09-12 18:56:25.512: e/androidruntime(616): caused by: java.lang.classnotfoundexception: com.example.test2.activity_main 09-12 18:56:25.512: e/androidruntime(616):  @ dalvik.system.basedexclassloader.findclass(basedexclassloader.java:61) 09-12 18:56:25.512: e/androidruntime(616):  @ java.lang.classloader.loadclass(classloader.java:501) 09-12 18:56:25.512: e/androidruntime(616):  @ java.lang.classloader.loadclass(classloader.java:461) 09-12 18:56:25.512: e/androidruntime(616):  @ android.app.instrumentation.newactivity(instrumentation.java:1053) 09-12 18:56:25.512: e/androidruntime(616):  @ android.app.activitythread.performlaunchactivity(activitythread.java:1974) 09-12 18:56:25.512: e/androidruntime(616):  ... 11 more 

funkcja.java

package com.example.test2;   import android.app.actionbar; import android.app.activity; import android.os.build; import android.os.bundle; import android.view.view; import android.view.view.onclicklistener; import android.view.windowmanager; import android.widget.button; import android.widget.edittext; import android.widget.textview; import android.widget.toast;  public class funkcja extends activity {     textview wynik;     button przelicz;     edittext wspxa, wspxb, wspya, wspyb;     double n1;       public void oncreate(bundle savedinstancestate) {           super.oncreate(savedinstancestate);             setcontentview(r.layout.activity_main);          //referencje         wynik = (textview) findviewbyid(r.id.wynik);         przelicz = (button) findviewbyid(r.id.przelicz);         wspxa = (edittext) findviewbyid(r.id.wspxa);         wspya = (edittext) findviewbyid(r.id.wspya);         wspxb = (edittext) findviewbyid(r.id.wspxb);         wspyb = (edittext) findviewbyid(r.id.wspyb);         //hiding status bar             if (build.version.sdk_int < 16) {            getwindow().setflags(windowmanager.layoutparams.flag_fullscreen,                    windowmanager.layoutparams.flag_fullscreen);        }        view decorview = getwindow().getdecorview();     int uioptions = view.system_ui_flag_fullscreen;     decorview.setsystemuivisibility(uioptions);     actionbar actionbar = getactionbar();     actionbar.hide();     przelicz.setonclicklistener(new onclicklistener(){          public void onclick(view v) {         try{             if(wspxa!=null){             double n1 = double.parsedouble(wspxa.gettext().tostring());             if (n1!=0){                 string total = double.tostring(n1);                 wynik.settext(total);             }             }         }         catch(exception e){         toast.maketext(getbasecontext(), "bledne dane", toast.length_long).show();         }         }     });      }  } 

manifest

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.example.test2"     android:versioncode="1"     android:versionname="1.0" >      <uses-sdk         android:minsdkversion="16"         android:targetsdkversion="16" />      <application         android:allowbackup="true"         android:icon="@drawable/ic_launcher"         android:label="@string/app_name"         android:theme="@style/apptheme" >         <activity             android:name=".activity_main"             android:label="@string/app_name" >             <intent-filter>                 <action android:name="android.intent.action.main" />                  <category android:name="android.intent.category.launcher" />             </intent-filter>         </activity>     </application>  </manifest> 

layout:

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:paddingbottom="@dimen/activity_vertical_margin"     android:paddingleft="@dimen/activity_horizontal_margin"     android:paddingright="@dimen/activity_horizontal_margin"     android:paddingtop="@dimen/activity_vertical_margin"     tools:context="activity_main" >      <spinner         android:id="@+id/spinner1"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_above="@+id/literaa"         android:layout_alignleft="@+id/literaa" />    <edittext         android:id="@+id/wspya"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_above="@+id/literab"         android:layout_torightof="@+id/przelicz"         android:ems="10"         android:inputtype="numberdecimal"         android:width="50dp" />      <edittext         android:id="@+id/wspyb"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignbaseline="@+id/wspxb"         android:layout_alignbottom="@+id/wspxb"         android:layout_alignleft="@+id/wspya"         android:ems="10"         android:inputtype="numberdecimal"         android:width="50dp" />      <textview         android:id="@+id/ywynik"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@+id/przelicz"         android:layout_marginright="33dp"         android:layout_margintop="24dp"         android:layout_toleftof="@+id/wynik"         android:text="y="         android:textappearance="?android:attr/textappearancelarge" />      <button         android:id="@+id/przelicz"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@+id/wspxb"         android:layout_centerhorizontal="true"         android:layout_margintop="24dp"         android:text="przelicz" />      <edittext         android:id="@+id/wspxa"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_above="@+id/literab"         android:layout_centerhorizontal="true"         android:ems="10"         android:inputtype="numberdecimal"         android:width="50dp" />      <edittext         android:id="@+id/wspxb"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignbottom="@+id/literab"         android:layout_alignleft="@+id/wspxa"         android:ems="10"         android:inputtype="numberdecimal"         android:width="50dp" >          <requestfocus />     </edittext>      <textview         android:id="@+id/literab"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@+id/literaa"         android:layout_marginright="18dp"         android:layout_margintop="33dp"         android:layout_toleftof="@+id/przelicz"         android:text="punkt b:"         android:textsize="20sp" />      <textview         android:id="@+id/literaa"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignleft="@+id/literab"         android:layout_alignparenttop="true"         android:layout_margintop="56dp"         android:text="punkt a:"         android:textsize="20sp" />      <textview         android:id="@+id/textview1"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_above="@+id/wspxa"         android:layout_centerhorizontal="true"         android:layout_marginbottom="14dp"         android:text="x"         android:textsize="22sp" />      <textview         android:id="@+id/textview01"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignbaseline="@+id/textview1"         android:layout_alignbottom="@+id/textview1"         android:layout_alignleft="@+id/wspya"         android:layout_marginleft="16dp"         android:text="y"         android:textsize="22sp" />      <textview         android:id="@+id/wynik"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignbottom="@+id/ywynik"         android:layout_alignright="@+id/wspyb"         android:layout_aligntop="@+id/ywynik"         android:layout_torightof="@+id/literaa"         android:textappearance="?android:attr/textappearancelarge" />   </relativelayout> 

your manifest has activity_main activity's java class name. change funkcja, actual java class name activity.