Gradle build failure when trying to use Facebook SDK

android, android-studio, facebook, gradle

Solution

You're adding the android support library twice, resulting in a dex merge conflict. Your main project refers to the maven library with `'com.android.support:support-v4:13.0.+'` and your Facebook project refers to it with `files('libs/android-support-v4.jar')`. Gradle cannot resolve conflicts between local jar files, so you must refer to them through maven.

Modify the `dependencies` section of your Facebook build.gradle to:

dependencies {
    compile 'com.android.support:support-v4:13.0.+'
}

and everything should work.

Problem

I am trying to use the Facebook SDK in a project in Android Studio. I am following step 3 of this tutorial. When I try to Run the app, I get a "Gradle: Execution failed for task ':FacebookApp:dexDebug'." error. Below is the output if the error ``` Gradle: Execution failed for task ':FacebookApp:dexDebug'. > Failed to run command: C:\android-sdk\build-tools\18.0.0\dx.bat --dex --output C:\Users\Brandon\AndroidStudioProjects\FacebookAppProject\FacebookApp\build\libs\FacebookApp-debug.dex C:\Users\Brandon\AndroidStudioProjects\FacebookAppProject\FacebookApp\build\classes\debug C:\Users\Brandon\AndroidStudioProjects\FacebookAppProject\FacebookApp\build\dependency-cache\debug C:\Users\Brandon\AndroidStudioProjects\FacebookAppProject\FacebookApp\build\exploded-bundles\FacebookAppProjectLibrariesFacebookUnspecified.aar\classes.jar C:\Users\Brandon\AndroidStudioProjects\FacebookAppProject\FacebookApp\build\exploded-bundles\FacebookAppProjectLibrariesFacebookUnspecified.aar\libs\android-support-v4.jar C:\android-sdk\extras\android\m2repository\com\android\support\support-v4\13.0.0\support-v4-13.0.0.jar Error Code: 1 Output: UNEXPECTED TOP-LEVEL EXCEPTION: java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoIcsImpl; at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123) at com.android.dx.dex.file.DexFile.add(DexFile.java:163) at com.android.dx.command.dexer.Main.processClass(Main.java:490) at com.android.dx.command.dexer.Main.processFileBytes(Main.java:459) at com.android.dx.command.dexer.Main.access$400(Main.java:67) at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:398) at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245) at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131) at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109) at com.android.dx.command.dexer.Main.processOne(Main.java:422) at com.android.dx.command.dexer.Main.processAllFiles(Main.java:333) at com.android.dx.command.dexer.Main.run(Main.java:209) at com.android.dx.command.dexer.Main.main(Main.java:174) at com.android.dx.command.Main.main(Main.java:91) 1 error; aborting ``` Here is the build.gradle for the facebook module: ``` buildscript { repositories { maven { url 'http://repo1.maven.org/maven2' } } dependencies { classpath 'com.android.tools.build:gradle:0.5.+' } } apply plugin: 'android-library' dependencies { compile files('libs/android-support-v4.jar') } android { compileSdkVersion 18 buildToolsVersion "18.0.0" defaultConfig { minSdkVersion 7 targetSdkVersion 16 } sourceSets { main { manifest.srcFile 'AndroidManifest.xml' java.srcDirs = ['src'] resources.srcDirs = ['src'] res.srcDirs = ['res'] } } } ``` And the build.gradle for the project: ``` buildscript { repositories { mavenCentral() } dependencies { classpath 'com.android.tools.build:gradle:0.5.+' } } apply plugin: 'android' repositories { mavenCentral() } dependencies { compile 'com.android.support:support-v4:13.0.+' compile project(':libraries:facebook') } android { compileSdkVersion 18 buildToolsVersion "18.0.0" defaultConfig { minSdkVersion 7 targetSdkVersion 16 } } ``` Am I doing something wrong?

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