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ANDROID STUDIO builds succesfully but doesn't run

I've just built my first android app copying the code from this video: https://www.youtube.com/watch?v=gTy13ioTddg&t=594s
The app builds without problems but when I try to run it, it suddenly closes.
That's the message of the debugger:
12/02 12:19:56: Launching 'app' on Pixel_3a_API_30_x86.
Install successfully finished in 519 ms.
$ adb shell am start -n "com.example.pokedex/com.example.pokedex.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER -D
Waiting for application to come online: com.example.pokedex | com.example.pokedex.test
Waiting for application to come online: com.example.pokedex | com.example.pokedex.test
Connecting to com.example.pokedex
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
W/ActivityThread: Application com.example.pokedex is waiting for the debugger on port 8100...
I/System.out: Sending WAIT chunk
I/System.out: Debugger has connected
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
Connected to the target VM, address: 'localhost:52033', transport: 'socket'
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/System.out: waiting for debugger to settle...
I/chatty: uid=10153(com.example.pokedex) identical 2 lines
I/System.out: waiting for debugger to settle...
I/System.out: debugger has settled (1475)
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/NetworkSecurityConfig: No Network Security Config specified, using platform default
D/libEGL: loaded /vendor/lib/egl/libEGL_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv1_CM_emulation.so
D/libEGL: loaded /vendor/lib/egl/libGLESv2_emulation.so
W/example.pokede: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
W/example.pokede: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.pokedex, PID: 8349
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.pokedex/com.example.pokedex.MainActivity}: android.view.InflateException: Binary XML file line #2 in com.example.pokedex:layout/activity_main: Binary XML file line #2 in com.example.pokedex:layout/activity_main: Error inflating class android.support.constraint.ConstraintLayout
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
Caused by: android.view.InflateException: Binary XML file line #2 in com.example.pokedex:layout/activity_main: Binary XML file line #2 in com.example.pokedex:layout/activity_main: Error inflating class android.support.constraint.ConstraintLayout
Caused by: android.view.InflateException: Binary XML file line #2 in com.example.pokedex:layout/activity_main: Error inflating class android.support.constraint.ConstraintLayout
Caused by: java.lang.ClassNotFoundException: android.support.constraint.ConstraintLayout
at java.lang.Class.classForName(Native Method)
at java.lang.Class.forName(Class.java:454)
at android.view.LayoutInflater.createView(LayoutInflater.java:813)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:1004)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:959)
at android.view.LayoutInflater.inflate(LayoutInflater.java:657)
at android.view.LayoutInflater.inflate(LayoutInflater.java:532)
at android.view.LayoutInflater.inflate(LayoutInflater.java:479)
at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:469)
at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at com.example.pokedex.MainActivity.onCreate(MainActivity.java:19)
at android.app.Activity.performCreate(Activity.java:8000)
at android.app.Activity.performCreate(Activity.java:7984)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
E/AndroidRuntime: Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.constraint.ConstraintLayout" on path: DexPathList[[zip file "/data/app/~~ikbXqJo2xtaJUvZzC7gM8Q==/com.example.pokedex-kRHbfAkGOaaI21CGLAjxuQ==/base.apk"],nativeLibraryDirectories=[/data/app/~~ikbXqJo2xtaJUvZzC7gM8Q==/com.example.pokedex-kRHbfAkGOaaI21CGLAjxuQ==/lib/x86, /system/lib, /system_ext/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:207)
at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
... 26 more
I/Process: Sending signal. PID: 8349 SIG: 9
Disconnected from the target VM, address: 'localhost:52033', transport: 'socket'
This is my Main Activity:
package com.example.pokedex;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private RecyclerView.Adapter adapter;
private RecyclerView.LayoutManager layoutManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView=findViewById(R.id.recycler_view);
adapter=new PokedexAdapter();
layoutManager=new LinearLayoutManager(this);
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(layoutManager);
}
}
Activity main.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/recycler_view"/>
</android.support.constraint.ConstraintLayout>
Pokedex_row:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/pokedex_row">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/pokedex_row_text_view"/>
</LinearLayout>
Android Manifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.pokedex">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.Pokedex">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
I've been trying to solve this problem several days so I would be very thankful if someone can help me!

Have tried you changing your ConstraintLayout to use androidx instead of support
try changing the opening tag of activity_main.xml to be:
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
and corresponding closing tag to be
</androidx.constraintlayout.widget.ConstraintLayout>
and then sync your project while connected to the internet.

I think it has problem with ConstraintLayout, can you share your xml files, that way I can help you batter.

I experience this error from time to time and use to solve by doing the following:
First, check if you have ConstraintLayout implementation in your app Gradle config
Then make sure there is no Error(maybe a semantic one) in your layout XML file
If the error persists, consider adding those two files to your question description so that one can easily help
Good Luck!

Android app keeps crashing on emulator and device [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 3 years ago.
I am executing a very basic task of opening another activity using a button. The code seems to be error-free but the app crashes without even showing the main activity. This happens on both the emulator as well as my device.
When the app has no function, i.e. when the app has just buttons which do nothing, the app works fine. But if I try to make them do anything(intent to open another activity, or to play with their visibility) the app crashes.
The logcat is as follows:
11-12 13:55:56.627 2962-2962/? D/AndroidRuntime: >>>>>> START com.android.internal.os.RuntimeInit uid 0 <<<<<<
11-12 13:55:56.628 2962-2962/? D/AndroidRuntime: CheckJNI is ON
11-12 13:55:56.672 2962-2962/? D/ICU: No timezone override file found: /data/misc/zoneinfo/current/icu/icu_tzdata.dat
11-12 13:55:56.754 2962-2962/? E/memtrack: Couldn't load memtrack module (No such file or directory)
11-12 13:55:56.754 2962-2962/? E/android.os.Debug: failed to load memtrack module: -2
11-12 13:55:56.755 2962-2962/? I/Radio-JNI: register_android_hardware_Radio DONE
11-12 13:55:56.761 2962-2962/? D/AndroidRuntime: Calling main entry com.android.commands.pm.Pm
11-12 13:55:56.772 2962-2962/? I/art: System.exit called, status: 0
11-12 13:55:56.772 2962-2962/? I/AndroidRuntime: VM exiting with result code 0.
11-12 13:55:57.068 2977-2977/? D/AndroidRuntime: >>>>>> START com.android.internal.os.RuntimeInit uid 0 <<<<<<
11-12 13:55:57.069 2977-2977/? D/AndroidRuntime: CheckJNI is ON
11-12 13:55:57.129 2977-2977/? D/ICU: No timezone override file found: /data/misc/zoneinfo/current/icu/icu_tzdata.dat
11-12 13:55:57.199 2977-2977/? E/memtrack: Couldn't load memtrack module (No such file or directory)
11-12 13:55:57.199 2977-2977/? E/android.os.Debug: failed to load memtrack module: -2
11-12 13:55:57.200 2977-2977/? I/Radio-JNI: register_android_hardware_Radio DONE
11-12 13:55:57.205 2977-2977/? D/AndroidRuntime: Calling main entry com.android.commands.pm.Pm
11-12 13:55:57.216 2977-2977/? I/art: System.exit called, status: 0
11-12 13:55:57.220 2977-2977/? I/AndroidRuntime: VM exiting with result code 0.
11-12 13:55:59.484 2987-2987/? D/AndroidRuntime: >>>>>> START com.android.internal.os.RuntimeInit uid 0 <<<<<<
11-12 13:55:59.487 2987-2987/? D/AndroidRuntime: CheckJNI is ON
11-12 13:55:59.522 2987-2987/? D/ICU: No timezone override file found: /data/misc/zoneinfo/current/icu/icu_tzdata.dat
11-12 13:55:59.602 2987-2987/? E/memtrack: Couldn't load memtrack module (No such file or directory)
11-12 13:55:59.602 2987-2987/? E/android.os.Debug: failed to load memtrack module: -2
11-12 13:55:59.603 2987-2987/? I/Radio-JNI: register_android_hardware_Radio DONE
11-12 13:55:59.615 2987-2987/? D/AndroidRuntime: Calling main entry com.android.commands.wm.Wm
11-12 13:55:59.643 2987-2987/? D/AndroidRuntime: Shutting down VM
11-12 13:56:01.407 2999-2999/? D/AndroidRuntime: >>>>>> START com.android.internal.os.RuntimeInit uid 0 <<<<<<
11-12 13:56:01.408 2999-2999/? D/AndroidRuntime: CheckJNI is ON
11-12 13:56:01.465 2999-2999/? D/ICU: No timezone override file found: /data/misc/zoneinfo/current/icu/icu_tzdata.dat
11-12 13:56:01.542 2999-2999/? E/memtrack: Couldn't load memtrack module (No such file or directory)
11-12 13:56:01.542 2999-2999/? E/android.os.Debug: failed to load memtrack module: -2
11-12 13:56:01.543 2999-2999/? I/Radio-JNI: register_android_hardware_Radio DONE
11-12 13:56:01.553 2999-2999/? D/AndroidRuntime: Calling main entry com.android.commands.am.Am
--------- beginning of system
11-12 13:56:01.562 1585-1920/system_process I/ActivityManager: START u0 {act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.example.dell.crash/.MainActivity} from uid 0 on display 0
11-12 13:56:01.579 2147-2341/com.google.android.googlequicksearchbox:search I/MicrophoneInputStream: mic_close com.google.android.apps.gsa.speech.audio.u#20f33e2
11-12 13:56:01.605 3007-3007/? I/art: Not late-enabling -Xcheck:jni (already on)
11-12 13:56:01.606 2147-2347/com.google.android.googlequicksearchbox:search I/HotwordRecognitionRnr: Stopping hotword detection.
11-12 13:56:01.606 2147-2699/com.google.android.googlequicksearchbox:search I/HotwordRecognitionRnr: Hotword detection finished
11-12 13:56:01.610 1585-1598/system_process I/ActivityManager: Start proc 3007:com.example.dell.crash/u0a64 for activity com.example.dell.crash/.MainActivity
11-12 13:56:01.604 2999-2999/? D/AndroidRuntime: Shutting down VM
[ 11-12 13:56:01.697 1585: 1608 D/ ]
HostConnection::get() New Host Connection established 0x7f8480e69e40, tid 1608
11-12 13:56:01.728 3007-3007/com.example.dell.crash W/System: ClassLoader referenced unknown path: /data/app/com.example.dell.crash-1/lib/x86_64
11-12 13:56:01.729 3007-3007/com.example.dell.crash I/InstantRun: Instant Run Runtime started. Android package is com.example.dell.crash, real application class is null.
11-12 13:56:02.906 1891-2316/com.google.android.googlequicksearchbox E/Surface: getSlotFromBufferLocked: unknown buffer: 0xe9e5e990
11-12 13:56:03.510 3007-3007/com.example.dell.crash W/System: ClassLoader referenced unknown path: /data/app/com.example.dell.crash-1/lib/x86_64
11-12 13:56:03.707 3007-3007/com.example.dell.crash D/AndroidRuntime: Shutting down VM
--------- beginning of crash
11-12 13:56:03.707 3007-3007/com.example.dell.crash E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.dell.crash, PID: 3007
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.dell.crash/com.example.dell.crash.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2327)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
at android.support.v7.app.AppCompatDelegateImplBase.<init>(AppCompatDelegateImplBase.java:116)
at android.support.v7.app.AppCompatDelegateImplV9.<init>(AppCompatDelegateImplV9.java:147)
at android.support.v7.app.AppCompatDelegateImplV11.<init>(AppCompatDelegateImplV11.java:27)
at android.support.v7.app.AppCompatDelegateImplV14.<init>(AppCompatDelegateImplV14.java:50)
at android.support.v7.app.AppCompatDelegateImplV23.<init>(AppCompatDelegateImplV23.java:29)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:199)
at android.support.v7.app.AppCompatDelegate.create(AppCompatDelegate.java:181)
at android.support.v7.app.AppCompatActivity.getDelegate(AppCompatActivity.java:521)
at android.support.v7.app.AppCompatActivity.findViewById(AppCompatActivity.java:190)
at com.example.dell.crash.MainActivity.<init>(MainActivity.java:10)
at java.lang.Class.newInstance(Native Method)
at android.app.Instrumentation.newActivity(Instrumentation.java:1067)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
at android.app.ActivityThread.-wrap11(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5417) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
11-12 13:56:03.708 1585-2055/system_process W/ActivityManager: Force finishing activity com.example.dell.crash/.MainActivity
11-12 13:56:04.016 1585-2055/system_process I/WindowManager: Screenshot max retries 4 of Token{9795bf6 ActivityRecord{989c091 u0 com.example.dell.crash/.MainActivity t51 f}} appWin=Window{a3bf3ce u0 Starting com.example.dell.crash} drawState=4
11-12 13:56:04.116 1585-2485/system_process I/OpenGLRenderer: Initialized EGL, version 1.4
11-12 13:56:04.518 1585-1601/system_process W/ActivityManager: Activity pause timeout for ActivityRecord{989c091 u0 com.example.dell.crash/.MainActivity t51 f}
11-12 13:56:04.550 2328-2336/com.google.android.gms W/SQLiteConnectionPool: A SQLiteConnection object for database '/data/user/0/com.google.android.gms/databases/networkstatistics.sqlite' was leaked! Please fix your application to end transactions in progress properly and to close the database when it is no longer needed.
11-12 13:56:04.550 2328-2336/com.google.android.gms W/SQLiteConnectionPool: A SQLiteConnection object for database '/data/user/0/com.google.android.gms/databases/metrics.db' was leaked! Please fix your application to end transactions in progress properly and to close the database when it is no longer needed.
11-12 13:56:04.551 2328-2336/com.google.android.gms W/SQLiteConnectionPool: A SQLiteConnection object for database '/data/user/0/com.google.android.gms/databases/help_responses.db' was leaked! Please fix your application to end transactions in progress properly and to close the database when it is no longer needed.
11-12 13:56:04.572 2328-2336/com.google.android.gms W/SQLiteConnectionPool: A SQLiteConnection object for database '/data/user/0/com.google.android.gms/databases/auto_complete_suggestions.db' was leaked! Please fix your application to end transactions in progress properly and to close the database when it is no longer needed.
11-12 13:56:04.860 1585-1602/system_process I/Choreographer: Skipped 35 frames! The application may be doing too much work on its main thread.
11-12 13:56:04.925 2147-3076/com.google.android.googlequicksearchbox:search I/HotwordRecognitionRnr: Starting hotword detection.
11-12 13:56:04.943 2147-3078/com.google.android.googlequicksearchbox:search I/MicrophoneInputStream: mic_starting com.google.android.apps.gsa.speech.audio.u#76753fd
11-12 13:56:04.955 1585-1599/system_process I/ActivityManager: Killing 2527:com.android.settings/1000 (adj 15): empty #17
11-12 13:56:04.965 1202-2042/? E/audio_hw_generic: Error opening input stream format 1, channel_mask 0010, sample_rate 16000
11-12 13:56:04.969 1202-3080/? I/AudioFlinger: AudioFlinger's thread 0xf3b80000 ready to run
11-12 13:56:04.988 2147-3078/com.google.android.googlequicksearchbox:search I/MicrophoneInputStream: mic_started com.google.android.apps.gsa.speech.audio.u#76753fd
11-12 13:56:04.991 2147-2341/com.google.android.googlequicksearchbox:search I/MicrophoneInputStream: mic_close com.google.android.apps.gsa.speech.audio.u#76753fd
11-12 13:56:04.992 2147-3078/com.google.android.googlequicksearchbox:search E/AudioRecord-JNI: Error -4 during AudioRecord native read
11-12 13:56:05.009 2147-2347/com.google.android.googlequicksearchbox:search I/HotwordRecognitionRnr: Stopping hotword detection.
11-12 13:56:05.010 2147-3076/com.google.android.googlequicksearchbox:search I/HotwordRecognitionRnr: Hotword detection finished
11-12 13:56:05.140 1585-1599/system_process I/ActivityManager: Killing 2649:com.android.dialer/u0a4 (adj 15): empty #17
11-12 13:56:05.395 1891-2316/com.google.android.googlequicksearchbox W/OpenGLRenderer: Incorrectly called buildLayer on View: em, destroying layer...
11-12 13:56:05.447 1585-1608/system_process D/gralloc_ranchu: gralloc_unregister_buffer: exiting HostConnection (is buffer-handling thread)
11-12 13:56:05.466 2328-2472/com.google.android.gms I/Icing: Usage reports 0 indexed 0 rejected 0 imm upload true
11-12 13:56:05.486 2328-2504/com.google.android.gms I/Icing: Usage reports 0 indexed 0 rejected 0 imm upload true
11-12 13:56:05.499 1585-1920/system_process I/ActivityManager: Killing 2670:com.android.managedprovisioning/u0a8 (adj 15): empty #17
11-12 13:56:15.034 1585-1601/system_process W/ActivityManager: Activity destroy timeout for ActivityRecord{989c091 u0 com.example.dell.crash/.MainActivity t51 f}
11-12 13:56:15.075 2147-3230/com.google.android.googlequicksearchbox:search W/CronetSyncConnectionRcs: Upload content type not set.
11-12 13:56:17.062 3007-3007/com.example.dell.crash I/Process: Sending signal. PID: 3007 SIG: 9
11-12 13:56:17.093 1585-2485/system_process E/Surface: getSlotFromBufferLocked: unknown buffer: 0x7f849297e160
11-12 13:56:17.101 1585-2485/system_process D/OpenGLRenderer: endAllStagingAnimators on 0x7f84835bfc00 (RippleDrawable) with handle 0x7f847ee9ee60
11-12 13:56:17.131 1585-1920/system_process W/InputMethodManagerService: Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy#9d97b24 attribute=null, token = android.os.BinderProxy#32922a9
11-12 13:56:17.165 1585-1920/system_process I/ActivityManager: Process com.example.dell.crash (pid 3007) has died
11-12 13:56:17.367 1585-1608/system_process W/AppOps: Finishing op nesting under-run: uid 1000 pkg android code 24 time=0 duration=0 nesting=0
11-12 13:56:17.409 2147-3268/com.google.android.googlequicksearchbox:search I/HotwordRecognitionRnr: Starting hotword detection.
11-12 13:56:17.413 2147-3269/com.google.android.googlequicksearchbox:search I/MicrophoneInputStream: mic_starting com.google.android.apps.gsa.speech.audio.u#898b349
11-12 13:56:17.423 1202-1546/? E/audio_hw_generic: Error opening input stream format 1, channel_mask 0010, sample_rate 16000
11-12 13:56:17.444 1202-3273/? I/AudioFlinger: AudioFlinger's thread 0xf3b80000 ready to run
11-12 13:56:17.449 2147-2157/com.google.android.googlequicksearchbox:search I/art: Background sticky concurrent mark sweep GC freed 1466(93KB) AllocSpace objects, 0(0B) LOS objects, 9% free, 4MB/4MB, paused 25.294ms total 31.038ms
11-12 13:56:17.456 2147-3269/com.google.android.googlequicksearchbox:search I/MicrophoneInputStream: mic_started com.google.android.apps.gsa.speech.audio.u#898b349
11-12 13:56:17.493 2147-2147/com.google.android.googlequicksearchbox:search I/HotwordWorker: onReady
11-12 13:56:17.504 2328-3272/com.google.android.gms W/IcingInternalCorpora: getNumBytesRead when not calculated.
11-12 13:56:17.564 2328-2472/com.google.android.gms I/Icing: Usage reports 0 indexed 0 rejected 0 imm upload true
11-12 13:56:17.571 2328-2472/com.google.android.gms I/Icing: Usage reports 0 indexed 0 rejected 0 imm upload true
11-12 13:56:18.155 1202-1544/? W/AudioFlinger: write blocked for 408 msecs, 4 delayed writes, thread 0xf4500000
The .java file has the following block:
public class MainActivity extends AppCompatActivity {
Button btn1 = (Button) findViewById(R.id.button);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(MainActivity.this, Main2Activity.class));
}
});
}
}
The XML file is as follows:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.dell.crash.MainActivity">
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="102dp"
android:id="#+id/button" />
</RelativeLayout>
I am using Android Studio 2.2.2

After
setContentView(R.layout.activity_main);
Add call like this
Button button = (Button) findViewById(R.id.button);
issue was you didn't created reference for button.

put Button btn1 = (Button) findViewById(R.id.button); in oncreate method.
The reason is you try add an event to your button but didn't show the reference id inside oncreate from where every app start its activity.

You should always instantiate button inside onCreate(). So your code should be like
public class MainActivity extends AppCompatActivity {
Button btn1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1 = (Button) findViewById(R.id.button);
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(MainActivity.this, Main2Activity.class));
}
});
}
}

If you init your btn1 variable in declarations section, it will run before the setContextView(...) function call. Put btn1 initialization after setContextView(...)!
public class MainActivity extends AppCompatActivity {
private Button btn1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1 = Button.class.cast(findViewById(R.id.button));
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(MainActivity.this, Main2Activity.class));
}
});
}
}

Maps on Android application

Hi everybody? The problem is on the title! I can't display my OsMap.map which I have put on the sdcard card on my emulator.
Can someone tells me what's the problem?
First are the steps that I've done:
My MainActivity.Java:
package com.formation.macarte;
import java.io.File;
import java.io.IOException;
import org.mapsforge.android.maps.GeoPoint;
import org.mapsforge.android.maps.MapActivity;
import org.mapsforge.android.maps.MapController;
import org.mapsforge.android.maps.MapView;
import android.annotation.SuppressLint;
import android.os.Bundle;
//import android.view.Menu;
//import android.view.MenuItem;
import android.os.Environment;
public class MainActivity extends MapActivity {
MapController monController;
double longitude = 12.482883;
double latitude = 48.849076;
#SuppressLint("SdCardPath")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MapView mapView = new MapView(this);
mapView.setClickable(true);
mapView.setBuiltInZoomControls(true);
mapView.setMapFile(Environment.getExternalStorageDirectory().getAbsolutePath()
+ "/OsMap.map");
setContentView(mapView);
}
}
And in my androidManifest, I have this:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.formation.macarte"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="20" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<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>
The file OsMap.map is already in mnt/sdcard like:
and in Edit Android Virtual Device: I have made one configuration: On the SD Card section, I had put C:\Android\adt-bundle-windows-x86-20140702\sdcard\osm.iso
So I've created a osm.iso to contain all my sdcard files, I've seen that in one tuto. And when I push one file from the DDMS, I can verify this same file in this osm.iso. So I think that it's correct!
And when I run this application, I can only display the ZoomControler, without the map. And sometimes, it shows this next error:
10-12 13:21:27.105: E/Trace(1727): error opening trace file: No such file or directory (2)
10-12 13:21:27.995: D/dalvikvm(1727): GC_CONCURRENT freed 72K, 8% free 2770K/2992K, paused 25ms+6ms, total 106ms
10-12 13:21:27.995: D/dalvikvm(1727): WAIT_FOR_CONCURRENT_GC blocked 92ms
10-12 13:21:28.135: D/dalvikvm(1727): GC_CONCURRENT freed 13K, 7% free 3163K/3388K, paused 20ms+13ms, total 110ms
10-12 13:21:28.135: D/dalvikvm(1727): WAIT_FOR_CONCURRENT_GC blocked 29ms
10-12 13:21:28.215: D/osm(1727): main: invalid map start position latitude: 1718579815
10-12 13:21:28.515: I/Choreographer(1727): Skipped 38 frames! The application may be doing too much work on its main thread.
10-12 13:21:28.855: D/dalvikvm(1727): GC_CONCURRENT freed 86K, 7% free 3478K/3712K, paused 11ms+11ms, total 113ms
10-12 13:21:28.855: D/dalvikvm(1727): WAIT_FOR_CONCURRENT_GC blocked 93ms
10-12 13:21:29.045: I/Choreographer(1727): Skipped 172 frames! The application may be doing too much work on its main thread.
10-12 13:21:29.324: D/gralloc_goldfish(1727): Emulator without GPU emulation detected.
10-12 13:21:32.465: I/Choreographer(1727): Skipped 45 frames! The application may be doing too much work on its main thread.
10-12 13:21:32.535: I/Choreographer(1727): Skipped 39 frames! The application may be doing too much work on its main thread.
10-12 13:21:32.575: I/Choreographer(1727): Skipped 33 frames! The application may be doing too much work on its main thread.
10-12 13:21:32.645: I/Choreographer(1727): Skipped 31 frames! The application may be doing too much work on its main thread.
10-12 13:21:32.785: I/Choreographer(1727): Skipped 116 frames! The application may be doing too much work on its main thread.
10-12 13:21:32.925: I/Choreographer(1727): Skipped 32 frames! The application may be doing too much work on its main thread.
10-12 13:21:33.005: I/Choreographer(1727): Skipped 40 frames! The application may be doing too much work on its main thread.
10-12 13:21:33.085: I/Choreographer(1727): Skipped 33 frames! The application may be doing too much work on its main thread.
10-12 13:21:39.675: I/Choreographer(1727): Skipped 36 frames! The application may be doing too much work on its main thread.
How can I solve this problem?

NullPointerException in Android when declaring a Content Provider

I'm facing a strange issue when declaring a Content Provider in my project. I'm copying the classes and Manifest declaration from another project of my own. It's working OK on my other project.
Here's part of my Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.qr"
android:installLocation="auto"
android:versionCode="540"
android:versionName="5.4" >
(...)
<application
android:name=".Application"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:logo="#drawable/ic_launch" >
(...)
<provider
android:name=".provider.HistoryProvider"
android:authorities="com.example.qr.History"
android:exported="true"
android:multiprocess="true"
android:readPermission="com.example.qr.History.read"
android:writePermission="com.example.qr.History.write" />
(...)
</application>
</manifest>
When I run my app, I get this stack trace:
FATAL EXCEPTION: main
java.lang.NullPointerException
at android.app.ActivityThread.installProvider(ActivityThread.java:4783)
at android.app.ActivityThread.installContentProviders(ActivityThread.java:4430)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4372)
at android.app.ActivityThread.access$1300(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1294)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5039)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
This is the whole stack trace. No 'com.example' trace is included. Of course some code in my app is producing this but the actual crash happens in Android.
Because my own classes are not included in the stack trace, I really don't know where to look.
I've run the code in an emulator with Android 4.2 and I've compared it with the source code of that version of Android, so I know the crash is produced in this line of ActivityThread:
4782 ApplicationInfo ai = info.applicationInfo;
4783 if (context.getPackageName().equals(ai.packageName)) {
Here's a link to the source code of this class.
If I don't declare the content provider (i.e. if I remove from my Manifest), the app works perfectly.
I've added some logs to my Application class, as well as the main Activity class. The crash is produced before either is launched.
So, my question is: what in my code can be producing context, context.getPackageName() or info.applicationInfo to be null during installation?
EDIT
When triggering the stack trace in the emulator several times, I only get this between traces:
09-11 23:10:21.250: E/AndroidRuntime(933): at dalvik.system.NativeStart.main(Native Method)
09-11 23:10:21.470: D/dalvikvm(933): GC_CONCURRENT freed 142K, 9% free 2951K/3224K, paused 78ms+3ms, total 225ms
09-11 23:10:44.030: I/Process(933): Sending signal. PID: 933 SIG: 9
09-11 23:10:46.940: D/dalvikvm(947): GC_CONCURRENT freed 164K, 10% free 2711K/2996K, paused 13ms+114ms, total 201ms
09-11 23:10:47.170: I/ActivityThread(947): Pub com.example.qr.History: com.example.qr.provider.HistoryProvider
09-11 23:10:47.170: D/AndroidRuntime(947): Shutting down VM
09-11 23:10:47.170: W/dalvikvm(947): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
09-11 23:10:47.180: E/AndroidRuntime(947): FATAL EXCEPTION: main

Error inflating class com.google.ads.AdView

Hello I am new to android dev and admob. I am trying to make a simple test app with a button, a couple pages and admob at the bottom. Everything works fine until I try implementing admob. Here is my code:
HelloAndroid.java:
package com.manny.HelloAndroid;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
public class HelloAndroid extends Activity {
/** Called when the activity is first created. */
private static final int ACTIVITY_CREATE = 0;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView image = (ImageView) findViewById(R.id.test_image);
//image.setScaleType(ImageView.ScaleType.FIT_XY);
}
public void onClick(View v){
Intent i = new Intent(this, HelloPage2.class);
startActivityForResult(i, ACTIVITY_CREATE);
}
}
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ImageView
android:id="#+id/test_image"
android:src="#drawable/bak_vert_480x800"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:scaleType="fitXY"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello" />
<ImageButton
android:id="#+id/test_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/btn_arrow"
android:layout_marginLeft="100dp"
android:layout_marginTop="200dp"
android:onClick="onClick"
/>
<com.google.ads.AdView android:id="#+id/adView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
ads:adUnitId="b14be806e9ddf1f"
ads:adSize="BANNER"
ads:testDevices="TEST_EMULATOR, TEST_DEVICE_ID"
ads:loadAdOnCreate="true"/>
</RelativeLayout>
hello android Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.manny.HelloAndroid"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="7"
android:targetSdkVersion="13"/>
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#android:style/Theme.NoTitleBar.Fullscreen">
<activity
android:name=".HelloAndroid"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".HelloPage2">
</activity>
<activity android:name="com.google.ads.AdActivity"
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|s mallestScreenSize"/>
</application>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
</manifest>
logcat output:
05-09 13:12:00.859: D/dalvikvm(24278): GC_EXTERNAL_ALLOC freed 51K, 44% free 3054K/5379K, external 2357K/2773K, paused 94ms
05-09 13:12:00.937: D/dalvikvm(24278): GC_EXTERNAL_ALLOC freed 1K, 44% free 3053K/5379K, external 3857K/4816K, paused 31ms
05-09 13:12:01.085: D/AndroidRuntime(24278): Shutting down VM
05-09 13:12:01.085: W/dalvikvm(24278): threadid=1: thread exiting with uncaught exception (group=0x4001e560)
05-09 13:12:01.109: E/AndroidRuntime(24278): FATAL EXCEPTION: main
05-09 13:12:01.109: E/AndroidRuntime(24278): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.manny.HelloAndroid/com.manny.HelloAndroid.HelloAndroid}: android.view.InflateException: Binary XML file line #30: Error inflating class com.google.ads.AdView
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1702)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1722)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.ActivityThread.access$1500(ActivityThread.java:124)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:974)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.os.Handler.dispatchMessage(Handler.java:99)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.os.Looper.loop(Looper.java:130)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.ActivityThread.main(ActivityThread.java:3821)
05-09 13:12:01.109: E/AndroidRuntime(24278): at java.lang.reflect.Method.invokeNative(Native Method)
05-09 13:12:01.109: E/AndroidRuntime(24278): at java.lang.reflect.Method.invoke(Method.java:507)
05-09 13:12:01.109: E/AndroidRuntime(24278): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-09 13:12:01.109: E/AndroidRuntime(24278): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-09 13:12:01.109: E/AndroidRuntime(24278): at dalvik.system.NativeStart.main(Native Method)
05-09 13:12:01.109: E/AndroidRuntime(24278): Caused by: android.view.InflateException: Binary XML file line #30: Error inflating class com.google.ads.AdView
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-09 13:12:01.109: E/AndroidRuntime(24278): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:253)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.Activity.setContentView(Activity.java:1716)
05-09 13:12:01.109: E/AndroidRuntime(24278): at com.manny.HelloAndroid.HelloAndroid.onCreate(HelloAndroid.java:17)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1666)
05-09 13:12:01.109: E/AndroidRuntime(24278): ... 11 more
05-09 13:12:01.109: E/AndroidRuntime(24278): Caused by: java.lang.ClassNotFoundException: com.google.ads.AdView in loader dalvik.system.PathClassLoader[/data/app/com.manny.HelloAndroid-2.apk]
05-09 13:12:01.109: E/AndroidRuntime(24278): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
05-09 13:12:01.109: E/AndroidRuntime(24278): at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
05-09 13:12:01.109: E/AndroidRuntime(24278): at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.view.LayoutInflater.createView(LayoutInflater.java:471)
05-09 13:12:01.109: E/AndroidRuntime(24278): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:570)
05-09 13:12:01.109: E/AndroidRuntime(24278): ... 20 more
05-09 13:12:11.593: I/Process(24278): Sending signal. PID: 24278 SIG: 9
I am using GoogleAdMobAdsSdkAndroid-6.0.0. Again I am very new to this and I have tried using examples off multiple sites but the app continues to crash when it hits a page with admob in it. If someone can help me it would be much appreciated. Thank you. If more code is needed let me know.

Have you recently updated your Android Tools to r17 or higher? If so, you need to create a libs/ folder in your project, and physically put the SDK in the project. Or, in the Java Build Path, you must Order and Export the SDK jar.
Otherwise, the jar doesn't get included when your apk gets compiled, and all hell breaks loose when you run AdMob code at runtime.
NOTE: This applies to any library your project references.

For me it worked like this.
close eclipse
add manually the sdk ad jar file in your project's "libs" folder
open eclipse
refresh your project till the sdk jar appears on libs folder
go to your project's properties > Java Build Path > Library Tab and choose "add Jars" instead of an external one. and select the sdk from the list below.
go to "Order and Export" tab and select again the SDK
click ok AND ITS DONE.
Then just add the proper code in the manifest and the xml.

I was experiencing this, too. The build path didn't seem to work no matter what I did. So I exited Eclipse, created a new libs folder in the workbench package directory. Added the GoogleAdMobAdsSdk-6.0.1.jar to that folder. I DID NOT add the whole SDK, just the jar file. Then restarted Eclipse. I had to refresh the project inspector column to show the changes I made outside of Eclipse. It showed the new libs folder and jar file, but it still didn't work... Then I right clicked on the new libs folder and set it as a SOURCE FOLDER. NOW EVERYTHING WORKS!
Im using Eclipse Version: Indigo Service Release 2
Build id: 20120216-1857
Android Development Tools 18.0.0.v201203301601-306762
It seems that maybe the tools are ahead of the documentation... or some kind of Eclipse bug.... Very aggravating!

I had the same problem and noticed that ordering the export list is also important.
This is mine, this way it works:

What I did - is working for me now - API Level 17
For admob:
- Add adview code to your Layout with appropriate ID
- Add Admob manifest code to your project manifest file
- Add an external GoogleAdmobAdsSDK....jar Jar file to your Library (in Properties\Java Build path)
- Check to choose GoogleAdmobAdsSDK....jar in tab Order and Export
- Restart your ADT
DEGUB = WORKING NOW.

In Android Studio:
1. Paste the Google AdMob SDK into the libs folder for your project
2. Add an entry to dependencies section of your build.gradle for the project pointing at the jar.
3. Rebuild your project
dependencies {
...
compile files('libs/GoogleAdMobAdsSdk-6.4.1.jar', '... other entries...')
}
Note that compile files takes multiple jar entries. If you already have a compile files entry you can just add to it by separating entries with a comma.

The same error appears to me and i solved with few simple steps
You need to remove the appcombat dependency from your project
for removing right click your project->android->remove app combat and make sure you have selected android 4.2.2
and then import the google admob jar into your project.