java对list进行分页

1import com.google.common.collect.Lists;
2
3import lombok.AllArgsConstructor;
4import lombok.Builder;
5import lombok.Getter;
6import lombok.NoArgsConstructor;
7import lombok.Setter;
8
9import java.util.Arrays;
10import java.util.List;
11import java.util.Optional;
12
13/**
14 * 对list进行分页
15 */
16@Getter
17@Setter
18@Builder
19@NoArgsConstructor
20@AllArgsConstructor
21public class PageResult<T> {
22    private List<T> resultList;
23
24    private String next;
25
26    private long total;
27
28    /**
29     * 内存list分页
30     * 从开始遍历的话，start请输入"0"
31     * 当返回的next为"0"时，表示到列表的末尾
32     *
33     * @param start start
34     * @param limit limit
35     * @param list list
36     * @param <T> T
37     * @return PageResult
38     */
39    public static <T> PageResult<T> pageList(int start, int limit, List<T> list) {
40        List<T> safeList = Optional.ofNullable(list).orElseGet(Lists::newArrayList);
41        int maxIndex = safeList.size();
42        int nextIndex = start + limit;
43        int fromIndex = Math.min(start, maxIndex);
44        int toIndex = Math.min(nextIndex, maxIndex);
45        String next = toIndex == maxIndex ? "0" : String.valueOf(nextIndex);
46        return PageResult.<T> builder()
47            .resultList(safeList.subList(fromIndex, toIndex))
48            .next(next)
49            .total(safeList.size())
50            .build();
51    }
52
53    public static void main(String[] args) {
54        PageResult<Integer> pageResult = PageResult.pageList(0, 2, Arrays.asList(1, 2, 3, 4, 5));
55    }
56}