Class android.support.v7.app.ActionBar.Callback has already been added to output. Please remove duplicate copies

Question

I am using Android Studio and Gradle. I have to problem from v7 ActionBar. I clean and build my project and that error :

Error : Class android.support.v7.app.ActionBar.Callback has already been added to output. Please remove duplicate copies.

Execution failed for task ':MobilOnay:dexDebug'. Could not call IncrementalTask.taskAction() on task ':MobilOnay:dexDebug'

build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.6.3'
    }
}

setting.gradle

include ':PageIndacator'
include ':MyProject'

MyProject/build.gradle

apply plugin: 'android'

dependencies {
    compile fileTree(dir: 'libs', include: '*.jar')
    compile project(':PageIndacator')
    compile 'com.android.support:appcompat-v7:18.0.+'
}

android {
    compileSdkVersion 19
    buildToolsVersion "19.0.0"

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
            assets.srcDirs = ['assets']
        }

        // Move the tests to tests/java, tests/res, etc...
        instrumentTest.setRoot('tests')

        // Move the build types to build-types/<type>
        // For instance, build-types/debug/java, build-types/debug/AndroidManifest.xml, ...
        // This moves them out of them default location under src/<type>/... which would
        // conflict with src/ being used by the main source set.
        // Adding new build types or product flavors should be accompanied
        // by a similar customization.
        debug.setRoot('build-types/debug')
        release.setRoot('build-types/release')
    }
}

PagaIndacator/build.gradle

apply plugin: 'android-library'

dependencies {
    compile 'com.android.support:support-v4:18.0.+'
}

android {
    compileSdkVersion 18
    buildToolsVersion "19.0.0"

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
            assets.srcDirs = ['assets']
        }

        // Move the tests to tests/java, tests/res, etc...
        instrumentTest.setRoot('tests')

        // Move the build types to build-types/<type>
        // For instance, build-types/debug/java, build-types/debug/AndroidManifest.xml, ...
        // This moves them out of them default location under src/<type>/... which would
        // conflict with src/ being used by the main source set.
        // Adding new build types or product flavors should be accompanied
        // by a similar customization.
        debug.setRoot('build-types/debug')
        release.setRoot('build-types/release')
    }
}

MyProject/libs

android-support-v7-appcompat.jar

PageIndacator/libs is Empty

Answer 1

You have to remove android-support-v7-appcompat.jar from your libs folder.

You are adding twice the same library. It is enought to use this dependency.

compile 'com.android.support:appcompat-v7:18.0.+'

You can also use the last version.

compile 'com.android.support:appcompat-v7:19.0.+'