NoClassDefFoundError: Failed resolution of: Landroid/support/v7/appcompat/R$styleable

Question

Newbie trying to finish the My first App tutorial provided by Google. On the way to this fatal exception I did import a lot of random packages to get rid of "cannot be resolved" errors for a number of things, ActionBarActivity, EditText, Fragment, LayoutInflater, etc, but not sure this matters. Anyway, my app crashes and produces a Fatal exception when I click on the "Send" button in the Main Activity. Here is my code and logcat file.

MyActivity.java (aka MainActivity.java of the tutorial)

package magiccoupons.tutapp;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;


public class MyActivity extends Activity {
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.my, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/** Called when the user clicks the Send button */
public void sendMessage(View view) {
    // Do something in response to button
    Intent intent = new Intent(this, DisplayMessageActivity.class);
    EditText editText = (EditText) findViewById(R.id.edit_message);
    String message = editText.getText().toString();
    intent.putExtra(EXTRA_MESSAGE, message);
    startActivity(intent);
}
}

DisplayMessageActivity.java:

package magiccoupons.tutapp;

import android.widget.*;
import android.content.Intent;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.*;
import android.support.v7.app.ActionBarActivity;
import android.app.Fragment;

public class DisplayMessageActivity extends ActionBarActivity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Get the message from the intent
    Intent intent = getIntent();
    String message = intent.getStringExtra(MyActivity.EXTRA_MESSAGE);

    // Create the text view
    TextView textView = new TextView(this);
    textView.setTextSize(40);
    textView.setText(message);

    // Set the text view as the activity layout
    setContentView(textView);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 *
public static class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() { }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.activity_display_message,
                container, false);
        return rootView;
    }
}
*/
}

build.gradle:

 apply plugin: 'com.android.application'

android {
    compileSdkVersion 'android-L'
    buildToolsVersion '20'

    defaultConfig {
        applicationId "magiccoupons.tutapp"
        minSdkVersion 20
        targetSdkVersion 20
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:support-v4:20.0.0'
    //compile 'com.android.support:appcompat-v7:21.0.0-rc1'
}

activity_my.xml:

    <LinearLayout 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:orientation="horizontal"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="magiccoupons.tutapp.MainActivity">

    <EditText android:id="@+id/edit_message"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="@string/edit_message" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button_send"
        android:onClick="sendMessage" />

</LinearLayout>

activity_display_message.xml:

<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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="magiccoupons.tutapp.DisplayMessageActivity">

<TextView
    android:text="@string/hello_world"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

</RelativeLayout>

and logcat:

08-21 11:24:36.088    3645-3645/magiccoupons.tutapp I/Process﹕ Sending signal. PID: 3645 SIG: 9
08-21 11:37:33.584    4149-4149/magiccoupons.tutapp W/Resources﹕ Preloaded drawable resource #0x1080093 (android:drawable/sym_def_app_icon) that varies with configuration!!
08-21 11:37:33.676    4149-4149/magiccoupons.tutapp I/am_on_resume_called﹕ [0,magiccoupons.tutapp.MyActivity]
08-21 11:37:33.905    4149-4149/magiccoupons.tutapp D/gralloc_goldfish﹕ Emulator without GPU emulation detected.
08-21 11:37:38.139    4149-4149/magiccoupons.tutapp I/am_on_paused_called﹕ [0,magiccoupons.tutapp.MyActivity]
08-21 11:37:38.218    4149-4149/magiccoupons.tutapp I/Choreographer﹕ Skipped 75 frames!  The application may be doing too much work on its main thread.
08-21 11:37:38.356    4149-4149/magiccoupons.tutapp D/AndroidRuntime﹕ Shutting down VM
08-21 11:37:38.369    4149-4149/magiccoupons.tutapp E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: magiccoupons.tutapp, PID: 4149
    java.lang.NoClassDefFoundError: Failed resolution of: Landroid/support/v7/appcompat/R$styleable;
            at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:106)
            at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:57)
            at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:99)
            at magiccoupons.tutapp.DisplayMessageActivity.onCreate(DisplayMessageActivity.java:15)
            at android.app.Activity.performCreate(Activity.java:5720)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1102)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2208)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
            at android.app.ActivityThread.access$800(ActivityThread.java:143)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5070)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
     Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v7.appcompat.R$styleable" on path: DexPathList[[zip file "/data/app/magiccoupons.tutapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/magiccoupons.tutapp-1, /vendor/lib, /system/lib]]
            at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
            at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:106)
            at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:57)
            at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:99)
            at magiccoupons.tutapp.DisplayMessageActivity.onCreate(DisplayMessageActivity.java:15)
            at android.app.Activity.performCreate(Activity.java:5720)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1102)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2208)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
            at android.app.ActivityThread.access$800(ActivityThread.java:143)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5070)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
    Suppressed: java.lang.ClassNotFoundException: android.support.v7.appcompat.R$styleable
            at java.lang.Class.classForName(Native Method)
            at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
            at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
            ... 18 more
     Caused by: java.lang.NoClassDefFoundError: Class "Landroid/support/v7/appcompat/R$styleable;" not found
            ... 22 more

Sorry if I missed something and this question is completely unnecessary and/or a dupe. Thanks.

Answer 1

Just
     Build -> Clean Project
and then
     Build -> Rebuild Project.
That's all.

Answer 2

You are getting that error because of the following reasons:

In your Gradle build file your app is targeting and compiling with the beta version of Android that is still in development with:

compileSdkVersion 'android-L'
buildToolsVersion '20'

as well as

minSdkVersion 20
targetSdkVersion 20

First thing to note is that this app will not run correctly (at this time) on any device without android-L flashed to it.

The real crux of your issue is in DisplayMessageActivity, it extends via inheritance [ActionBarActivity]:(https://developer.android.com/reference/android/support/v7/app/ActionBarActivity.html) this is one of the support library classes for AppCompat.

To fix this, change your min SDK to 10 (or 14 which is ice cream sandwich), your max SDK to 19 (Kit Kat) and un-comment the appcompat-v7 library in your dependencies.

As a side note, when you declare widgets in their respective activities/fragments it's usually good practice to have their scope be outside of any methods:

EditText editText;
Button sendMessageButton;

// Then in your onCreate() method
editText = (EditText) findViewById(R.id.editText);
sendMessageButton = (Button) findViewById(R.id.sendMessageButton);

This helps reduce memory re-allocation and make your code a little more readable. Sometimes you may have to bend the rules a bit but this is the common practice.

Answer 3

I deleted 'build' folder in "yourAppName\app" folder

and everything worked fine. If above solution didn't work, try this. build folder will be auto-generate when you build your project again.