Noclassdeffounderror - Can't find v7 support (android studio)

Question

so im trying to build an app using GCM. i've opened 2 modules for this. a backend (GCM messaging with appengine and a regular module - the names are "app" (regular module" and "backend").

i'm recieving this problem and i can't figure the solotion for it.

when the app is starting i get the following error:

10-04 18:24:16.391 18920-18920/com.example.daniel.testing6 E/AndroidRuntime﹕ FATAL EXCEPTION: main java.lang.NoClassDefFoundError: android.support.v7.appcompat.R$attr at android.support.v7.app.AppCompatDelegateImplV7.ensureSubDecor(AppCompatDelegateImplV7.java:289) at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:246) at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:106) at com.example.daniel.testing6.MainActivity.onCreate(MainActivity.java:14) at android.app.Activity.performCreate(Activity.java:5104) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230) at android.app.ActivityThread.access$600(ActivityThread.java:141) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5041) 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)

My project name is Testing6 and its gradle: // Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.2.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

my app module gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "23.0.0 rc2"

    defaultConfig {
        applicationId "com.example.daniel.testing6"
        minSdkVersion 15
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
        multiDexEnabled true // i added it because i got different problem
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.2.0'
    compile 'com.google.android.gms:play-services:8.1.0'
    compile project(path: ':backend', configuration: 'android-endpoints')
}

and my backend module:

// If you would like more information on the gradle-appengine-plugin please refer to the github page
// https://github.com/GoogleCloudPlatform/gradle-appengine-plugin

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.google.appengine:gradle-appengine-plugin:1.9.18'
    }
}

repositories {
    jcenter();
}

apply plugin: 'java'
apply plugin: 'war'
apply plugin: 'appengine'

sourceCompatibility = JavaVersion.VERSION_1_7
targetCompatibility = JavaVersion.VERSION_1_7

dependencies {
    appengineSdk 'com.google.appengine:appengine-java-sdk:1.9.18'
    compile 'com.google.appengine:appengine-endpoints:1.9.18'
    compile 'com.google.appengine:appengine-endpoints-deps:1.9.18'
    compile 'javax.servlet:servlet-api:2.5'
    compile 'com.googlecode.objectify:objectify:4.0b3'
    compile 'com.ganyo:gcm-server:1.0.2'
}

appengine {
    downloadSdk = true
    appcfg {
        oauth2 = true
    }
    endpoints {
        getClientLibsOnBuild = true
        getDiscoveryDocsOnBuild = true
    }
}

public class MainActivity extends MultiDexApplication {

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        MultiDex.install(this);
    }


}

doew anyone knows how to fix it???

Answer 1

Installing/updating Android Support Library and Android Support Repository in SDK manager will fix such errors

Answer 2

Problem Solved!

Ok so i did the following:

manifast:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.daniel.testing6" >

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />

    <permission
        android:name="com.example.gcm.permission.C2D_MESSAGE"
        android:protectionLevel="signature" />

    <uses-permission android:name="com.example.gcm.permission.C2D_MESSAGE" />

    <application
        android:name="com.example.daniel.testing6.Application"
        android:allowBackup="true"
        android:icon="@mipmap/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>
        <activity
            android:name=".Main2Activity"
            android:label="@string/title_activity_main2"
            android:theme="@style/AppTheme.NoActionBar" >
        </activity>
    </application>

</manifest>

ok so to get rid of the error i went to the gradle of my module app: so it will look like that:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "23.0.0 rc2"

    defaultConfig {
        applicationId "com.example.daniel.testing6"
        minSdkVersion 15
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile project(path: ':backend', configuration: 'android-endpoints')
    //
    compile 'com.android.support:appcompat-v7:22.2.1'
    compile 'com.google.android.gms:play-services:8.1.0'
    compile 'com.android.support:multidex:1.0.0'
    compile 'com.android.support:design:22.2.1'
}

next i created an Application as follows:

package com.example.daniel.testing6;

import android.content.Context;
import android.support.multidex.MultiDex;
import android.support.multidex.MultiDexApplication;

/**
 * Created by Daniel on 05-Oct-15.
 */
public class Application extends MultiDexApplication {
    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        MultiDex.install(this);
    }
}

and a main activity normally:

package com.example.daniel.testing6;

import android.content.Context;
import android.content.Intent;
import android.os.PersistableBundle;
import android.support.multidex.MultiDex;
import android.support.multidex.MultiDexApplication;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
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);

        startActivity(new Intent(this, Main2Activity.class));
    }

}

the manifast calls the Application that uploading all its data and then moves to the activity once the data is with in our reach :)

Answer 3

You also have to:

Include `compile 'com.android.support:multidex:1.0.0'` in your dependencies

See https://developer.android.com/tools/building/multidex.html for more details.

Also have your Application class extend MultiDexApplication instead of just Application. Alternatively, you can call MultiDex.install() in attachBaseContext() of your application