Seems your getter and setter of data.selectedWeeklyDayList is private. To your clone() problem. The interface List does not implement Cloneable. You have to use the actual Object. For example ArrayList. List<Object> list = new ArrayList<Object>(); list.clone(); <-- doesn't exist ((ArrayList) list).clone(); <-- unchecked cast to ArrayList. ArrayList implements Cloneable. or you use ArrayList itself. ArrayList<Object> list = new ArrayList<Object>();

Seems your getter and setter of data.selectedWeeklyDayList is private. To your clone() problem. The interface List does not implement Cloneable. You have to use the actual Object. For example ArrayList. List<Object> list = new ArrayList<Object>(); list.clone(); <-- doesn't exist ((ArrayList) list).clone(); <-- unchecked cast to ArrayList. ArrayList implements Cloneable. or you use ArrayList itself. ArrayList<Object> list = new ArrayList<Object>();

Seems your getter and setter of data.selectedWeeklyDayList is private. To your clone() problem. The interface List does not implement Cloneable. You have to use the actual Object. For example ArrayList. List<Object> list = new ArrayList<Object>(); list.clone(); <-- doesn't exist ((ArrayList) list).clone(); <-- unchecked cast to ArrayList. ArrayList implements Cloneable. or you use ArrayList itself. ArrayList<Object> list = new ArrayList<Object>();