import org.apache.commons.collections.CollectionUtils;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class DemoUtils {
    public Map<String, Object> query(String page, String limit) {

        List<Map<String, Object>> paramList = new ArrayList<>();//查询出来的List  对该List进行分页查询。
        List<Map<String, Object>> subList = new ArrayList<>();
        int totalCount = paramList.size();//总数量
        if (CollectionUtils.isNotEmpty(paramList)) {
            int pageCount = 0;//总页数
            int pageSize = Integer.parseInt(limit);//每页多少条
            int queryPage = Integer.parseInt(page);
            int m = totalCount % pageSize;
            if (m > 0) {
                pageCount = totalCount / pageSize + 1;
            } else {
                pageCount = totalCount / pageSize;
            }
            if (m == 0) {
                subList = paramList.subList((queryPage - 1) * pageSize, pageSize * (queryPage));
            } else {
                if (queryPage == pageCount) {
                    subList = paramList.subList((queryPage - 1) * pageSize, totalCount);
                } else if (queryPage < pageCount) {
                    subList = paramList.subList((queryPage - 1) * pageSize, pageSize * (queryPage));
                }
            }
        }
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("data", subList);
        map.put("count", totalCount);
        return map;
    }
}