java我如何在这里使用循环，我想每转一圈就从列表中删除3个元素

Question

我有一个包含一些元素的列表，当page num=1时，我需要打印前3个元素， 当page==2时，接下来的3个元素也是

public class OtherTemporaryTrials {

    public static void main(String[] args) {
        
        int numOfPages = 6;
        
        ArrayList<Integer> al = new ArrayList<Integer>();
        al.add(13);
        al.add(77);
        al.add(53);
        al.add(63);
        al.add(173);
        al.add(134);
        al.add(1366);
        al.add(13446);
        al.add(1333);
        al.add(1323);
        al.add(163);
        al.add(1335);
        al.add(13228);
        al.add(1573);
        al.add(13355);
        al.add(12343);
        al.add(12353);
        
        
        
        
        for(int i=0;i<numOfPages;i++) {
            
            setdata(al,numOfPages);
            
        }
    }

    private static void setdata(ArrayList<Integer> al, int numOfPages) {
        
        
        for(int i=0;i<3;i++) {

// Here for every next page we should get the next 3 elements from List
            System.out.println(al.get(i));
        }
        
    }

}

Answer 1

要访问页面大小为k的nth页面，需要获取范围为n * k到(n + 1) * k的元素。这可以使用subListAPI轻松完成：

public class Main {
    public static List<Integer> getPage(List<Integer> list, int pageSize, int pageNo) {
        // get the from & to range bounds, respecting the list length to prevent IndexOutOfBound exceptions
        int from = pageNo * pageSize;
        int to = Math.min(list.size(), (pageNo + 1) * pageSize);
        
        // return the expected slice of the list
        return list.subList(from, to);
    }

    public static void clearPage(List<Integer> list, int pageSize, int pageNo) {
        // get the from & to range bounds, respecting the list length to prevent IndexOutOfBound exceptions
        int from = pageNo * pageSize;
        int to = Math.min(list.size(), (pageNo + 1) * pageSize);
        
        // clear the expected slice from the list
        // this is allowed as long as the list is not "read-only"
        list.subList(from, to).clear(); 
    }

    public static void main(String[] args) {
        // need to use an array list because Arrays.asList return an immutable list (read-only)
        var list = new ArrayList<Integer>(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
        int pageSize = 3;

        // print pages
        System.out.println(getPage(list, pageSize, 0));
        System.out.println(getPage(list, pageSize, 1));
        System.out.println(getPage(list, pageSize, 2));
        System.out.println(getPage(list, pageSize, 3));

        System.out.println(list);

        // delete elements at position 0 to 2
        clearPage(list, pageSize, 0);
        System.out.println(list);

        // delete elements at position 3 to 5
        clearPage(list, pageSize, 1);
        System.out.println(list);
    }
}

因为这适用于基于零的索引，如果希望1表示第一页，则需要从页码中减去1，然后再使用它计算子列表的范围边界