title: NoClassDefFoundError after importing aar file - Android Studio
body: <p>I tried to use a customed aar file in my project. </p>
  
  <p>so, I added dependencies to "build.gradle" file. </p>
  
  <p>Here is my "build.gradle" file. </p>
  
  <pre><code>dependencies {
    compile "com.android.support:support-v4:18.0.0"
    compile "com.test:custom:0.0.1@aar
  }
  </code></pre>
  
  <p>And, here is the java file that I used the activity of the customed aar. </p>
  
  <pre><code>Intent sharingIntent = new Intent(MyProjectActivity.this, MainActivity.class);
  startActivity(sharingIntent);
  </code></pre>
  
  <p>When I compiled this project, there was no problem and "AndroidManifest.xml" file was merged well. 
  However, when I runed the application, an error occured and it terminated. </p>
  
  <p>Here is the error message. </p>
  
  <pre><code>Caused by: java.lang.NoClassDefFoundError: com.test.custom.MainActivity
          at com.project.MyProjectActivity.onRecommendClick(MyProjectActivity.java)
  </code></pre>
  
  <p>The problem is that the apk included resource files without classes.jar. </p>
  
  <p>How can I include the classes.jar of aar into the apk? </p>