Java：在自定义列表上使用addAll方法

Question

I am trying to use the addAll() method on custom list. I have the following Java code;

PaginatedResponse<CustomType> paginatedResponse = new PaginatedResponse<CustomType>();
List<PaginatedResponse<CustomType>> paginatedResponseList = new ArrayList<PaginatedResponse<CustomType>>();
paginatedResponseList.addAll(methodReturningPaginatedResponseOfCustomType);

However I am getting an error. no suitable method found for addAll()

What am I doing wrong here ?

Answer 1

If addAll method is called, then in your code example, methodReturningPaginatedResponseOfCustomType should be a type of collection type, like List< PaginatedResponse< CustomType > > .

If methodReturningPaginatedResponseOfCustomType is a type of PaginatedResponse< CustomType >, then you need to use add rather than addAll.

If methodReturningPaginatedResponseOfCustomType is a type of CustomType, then the element in list does not match with methodReturningPaginatedResponseOfCustomType that you would like to add.

Check if the type is macthing first.