not assignable to 'android.app.activity' extends application -

i implementing adobe creative sdk. getting following error in in my manifest file:

'com.example.nick.avierytest2.mainactivity not assignable android.app.activity'  

this xml file:

<?xml version="1.0" encoding="utf-8"?> 

<application     android:allowbackup="true"     android:icon="@mipmap/ic_launcher"     android:label="@string/app_name"     android:supportsrtl="true"     android:theme="@style/apptheme" >     <activity         android:name=".mainactivity"         android:label="@string/app_name"         android:theme="@style/apptheme.noactionbar" >         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity> </application> 

this main activity class:

public class mainactivity extends application implements iadobeauthclientcredentials {  /* sure fill in 2 strings below. */ private static final string creative_sdk_client_id = ""; private static final string creative_sdk_client_secret = "";  @override public void oncreate() {     super.oncreate();     adobecsdkfoundation.initializecsdkfoundation(             getapplicationcontext(),             adobeauthimsenvironment.adobeauthimsenvironmentproductionus     ); }  @override public string getclientid() {     return creative_sdk_client_id; }  @override public string getclientsecret() {     return creative_sdk_client_secret; } 

}

every other time have seen question on stackoverflow trying declare fragment in manifest not problem here , have not been able find solution.

thank help.

mainactivity extends application 

of course application not assignable activity.

either change mainactivity extends activity, or move android:name=".mainactivity" reference in manifest application tag (and remove activity). in latter case consider renaming class mainactivity e.g. myapplication.