When creating class objects in Java, the types are different.

MyObject object = new MyObject();

Action action = new BoardListAction();

package action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import vo.ActionForward;

public interface Action {
    ActionForward execute(HttpServletRequest request, HttpServletResponse response) throws Exception;

}

package action;

import java.util.ArrayList;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import svc.BoardListService;
import vo.ActionForward;
import vo.BoardBean;
import vo.PageInfo;

public class BoardListAction implements Action{
@Override
public ActionForward execute(HttpServletRequest request, HttpServletResponse response) throws Exception {
    // // TODO Auto-generated method stub

    ArrayList<BoardBean> articleList = new ArrayList<>(); // The part that creates the ArrayList object to store the entire list of articles to be output per page.
    int page=1;
    int limit = 10; // It is the part where the number of sentences to be output per page is set to 10.

    if(request.getParameter("page") != null) {
        page=Integer.parseInt(request.getParameter("page"); //The part that changes the value of the page variable when a page to be output in the list view is sent to the parameter.
        // In the list view page, click the page number you want to view, and if requested, the page number is sent to the pyrometer.
    }

    BoardListService boardListService = new BoardListService();
    intlistCount = boardListService.getListCount(); // The part that calls the method that returns the total number of statements.
    //with total list count
    articleList = boardListService.getArticleList(page,limit);
    //List Received
    //Total number of pages
    int maxPage=(int)((double)listCount/limit+0.95); // Add 0.95 to raise★★★★★★★
    //The number of start pages to show on the current page (1,11,21, etc.) ★★★★★★★★★★
    int startPage = (((int)((double)page/10 + 0.9)) -1) * 10 + 1;
    //The number of last pages to show on the current page. (10,20, 30, etc.) ★★★★★★★★★★★★★★★
    int endPage = startPage+10-1;

    if(endPage > maxPage) endPage=maxPage;

    PageInfo pageInfo = new PageInfo();
    pageInfo.setEndPage(endPage);
    pageInfo.setListCount(listCount);
    pageInfo.setMaxPage(maxPage);
    pageInfo.setPage(page);
    pageInfo.setStartPage(startPage);
    request.setAttribute("pageInfo", pageInfo);
    request.setAttribute("articleList", articleList);
    ActionForward forward = new ActionForward();
    forward.setPath("/board/qna_board_list.jsp");

    return forward;
}
}