My application has stopped unexpectedly on emulator

Question

Im new to android development ,im just following tutorials so while running project as android application on emulator it is showing "your application has stopped unfortunately". I have seen so many answers in stackoverflow but didn't get solution. I went to logcat also . what I have done just simply run my hello world in emulator but it was stopped.

1) this is my xml activity:

<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="com.examp.calc.MainActivity" >
<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello_world"
    android:textSize="40sp" />
 </RelativeLayout> 

2) Java source code : activity file

package com.examp.calc;
 import android.support.v7.app.ActionBarActivity;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
 public class MainActivity extends ActionBarActivity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}}

3)Mainfest file

`<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.examp.calc"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="19" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        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>
`

4)logcat error report:

03-10 06:56:55.347: D/AndroidRuntime(1761): Shutting down VM 03-10 06:56:55.347: W/dalvikvm(1761): threadid=1: thread exiting with ncaught exception (group=0xb0d77b20) 03-10 06:56:55.347: E/AndroidRuntime(1761): FATAL EXCEPTION: main 03-10 06:56:55.347: E/AndroidRuntime(1761): Process: com.examp.calc, PID: 1761 03-10 06:56:55.347: E/AndroidRuntime(1761): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.examp.calc/com.exam.calc.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.exam.calc.MainActivity" on path: DexPathList[[zip file "/data/app/com.examp.calc-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.examp.calc-1, /system/lib]] 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2121) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.app.ActivityThread.access$800(ActivityThread.java:135) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.os.Handler.dispatchMessage(Handler.java:102) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.os.Looper.loop(Looper.java:136) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.app.ActivityThread.main(ActivityThread.java:5017) 03-10 06:56:55.347: E/AndroidRuntime(1761): at java.lang.reflect.Method.invokeNative(Native Method) 03-10 06:56:55.347: E/AndroidRuntime(1761): at java.lang.reflect.Method.invoke(Method.java:515) 03-10 06:56:55.347: E/AndroidRuntime(1761): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 03-10 06:56:55.347: E/AndroidRuntime(1761): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 03-10 06:56:55.347: E/AndroidRuntime(1761): at dalvik.system.NativeStart.main(Native Method) 03-10 06:56:55.347: E/AndroidRuntime(1761): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.exam.calc.MainActivity" on path: DexPathList[[zip file "/data/app/com.examp.calc-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.examp.calc-1, /system/lib]] 03-10 06:56:55.347: E/AndroidRuntime(1761): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) 03-10 06:56:55.347: E/AndroidRuntime(1761): at java.lang.ClassLoader.loadClass(ClassLoader.java:497) 03-10 06:56:55.347: E/AndroidRuntime(1761): at java.lang.ClassLoader.loadClass(ClassLoader.java:457) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.app.Instrumentation.newActivity(Instrumentation.java:1061) 03-10 06:56:55.347: E/AndroidRuntime(1761): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2112) 03-10 06:56:55.347: E/AndroidRuntime(1761): ... 11 more

5) after debugging : source not found in debug thank you advance

Answer 1

Try changing your extends ActionBarActivity by extends Activity.

---

The compiler search for the package com.exam.calc but your package name is com.examp.calc.

In your Manifest, replace :

android:name="com.exam.calc.MainActivity"

By :

android:name="com.examp.calc.MainActivity"

---

If it's not working, you can try this...

Try deleting this line in your xml layout :

tools:context="com.examp.calc.MainActivity"

You should have :

    <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" >
        <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="@string/hello_world"
            android:textSize="40sp" />
   </RelativeLayout> 

Or if you prefer, you can delete the setContentView line of your Activity.

Answer 2

In Mainfest file : change this line

android:name="com.examp.calc.MainActivity"

Answer 3

You must not define;

tools:context="com.examp.calc.MainActivity"

and

setContentView(R.layout.activity_main);

at the same time. Just remove one of them and it will work properly.