对一个结果集（List）进行手动分页

对一个链表List，进行手动分页，核心代码就是pagin函数：

import lombok.extern.slf4j.Slf4j;
import org.junit.Before;
import org.junit.Test;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

@Slf4j
public class ImplementsPaging {
    private List<String> list;

    @Before
    public void init(){
        list = new ArrayList<>();
        list.add("Luo");
        list.add("Tian");
        list.add("yan");
        list.add("23");
        list.add("elegant");
        list.add("optimistic");
        list.add("mysterious");
        list.add("classical");
    }

    @Test
    public void testPaging(){
        Random random = new Random();
        int cursor = random.nextInt(3);
        int limit = random.nextInt(10);
        //分页之前
        list.forEach(l -> log.debug(l));

        //分页之后
        List<String> paging = paging(cursor, limit, list);
        paging.forEach(l -> log.debug(l));
    }

    public List<String> paging(int cursor, int limit, List<String> list){
        log.debug("cursor={} and limit={}",cursor,limit);
        //手动实现分页
        if (cursor < 0 || cursor >= list.size() || limit <= 0) {
            return null;
        }
        int lastIndex = cursor + limit;
        if (lastIndex > list.size()) {
            lastIndex = list.size();
        }

        //获得分页后的deviceIdList
        list = list.subList(cursor, lastIndex);

        return list;
    }
}

多次测试均能够达到正常分页效果。