private String getRunningActivityName() { 
        String contextString = context.toString(); 
        return contextString.substring(contextString.lastIndexOf(".") + 1, contextString.indexOf("@")); 
}

<uses-permission android:name="android.permission.GET_TASKS" /> 

private String getRunningActivityName(){         
        ActivityManager activityManager=(ActivityManager) getSystemService(Context.ACTIVITY_SERVICE); 
        String runningActivity=activityManager.getRunningTasks(1).get(0).topActivity.getClassName(); 
        return runningActivity;                
}