Android Studio - Importing external Library/Jar

I recently downloaded Android Studio to develop Android applications (I'm coming from Eclipse), and I am having issues using external libraries and/or external JAR files alongside my own project. NOTE: the following tests were conducted on a new application project created from scratch in Android Studio.

Example 1: JAR Import.

1. Download a fresh copy of the Admobs SDK from Google.

2. Copy the library jar GoogleAdMobAdsSdk-6.4.1.jar to the project's /libs/ folder.

3. In the project explorer, right click on the newly added library.jar and click on 'Add as Library'.

Technically at this point everything works, imports work just fine, the layout editor shows a preview of the AdView widget and all that. The only problem is that it doesn't compile successfully.

Log from console:

Gradle: 
FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':APITests:compilePaidDebug'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

Could not execute build using Gradle distribution 'http://services.gradle.org/distributions/gradle-1.6-bin.zip'.

I tried running gradlew compileDebug --stacktrace, and the problem seems to be that the despite being able to import the classes successfully in both the code & design editor, at compile time, it cannot resolve the imports. Here's the relevant part of the log: (full stacktrace here)

java:6: error: package com.google.ads does not exist
import com.google.ads.AdRequest;    
java:7: error: package com.google.ads does not exist
import com.google.ads.AdView;
java:11: error: cannot find symbol
AdView mAdView;
symbol:   class AdView
location: class MainActivity
java:22: error: cannot find symbol
mAdView = (AdView)this.findViewById(R.id.adView);
symbol:   class AdView
location: class MainActivity
java:23: error: cannot find symbol
mAdView.loadAd(new AdRequest());
symbol:   class AdRequest
location: class MainActivity
5 errors
:Test:compileDebug FAILED

But again, the imports work well in the editor, and the dependency is there:

It's also worth noting that without attempting to add a library/JAR, the projects compiles just fine.

I then tried editing the build.gradle file to include the new lib like this:

dependencies {
compile files('libs/android-support-v4.jar', 'libs/GoogleAdMobAdsSdk-6.4.1.jar')
}

This time, it did compile successfully, but the app now forces closes, as apparently, it cannot find a specific class from the lib in the application package.

Caused by: java.lang.ClassNotFoundException: Didn't find class "com.google.ads.AdView" on path: /data/app/com.foo.test-1.apk

Any ideas?

So,

Steps to follow in order to import a JAR sucesfully to your project using Android Studio 0.1.1:

• Download the library.jar file and copy it to your /libs/ folder inside your application project.
• Open the build.gradle file and edit your dependencies to include the new .jar file:

compile files('libs/android-support-v4.jar', 'libs/GoogleAdMobAdsSdk-6.4.1.jar')

• File -> Close Project
• Open a command prompt on your project's root location, i.e 'C:\Users\Username\AndroidStudioProjects\MyApplicationProject\'
• On the command prompt, type gradlew clean, wait till it's done.
• Reopen your application project in Android Studio.
• Test run your application and it should work succesfully.

You don't need to close the project and go to command line to invoke grade:clean. Go to Build-> Rebuild Project

Easy way and it works for me. Using Android Studio 0.8.2.

1. Drag jar file under libs.
2. Press "Sync Project with Gradle Files" button.

"simple solution is here"

1 .Create a folder named libs under the app directory for that matter any directory within the project..

2 .Copy Paste your Library to libs folder

3.You simply copy the JAR to your libs/ directory and then from inside Android Studio, right click the Jar that shows up under libs/ > Add As Library..

Peace!