用java实现的通用内存分页函数

经常需要用到在内存中进行分页处理，今天写了一个存起来，方便以后直接使用，不用再写了。

/**
 * @currPageNo  页面传入的页号，从一开始
 * @pageSize    每页记录数
 */
public  Map getPagingResultMap(List list, Integer currPageNo, Integer pageSize) {
    Map retMap = new HashMap<>();

    if (list.isEmpty()) {
        retMap.put("result", Collections.emptyList());
        retMap.put("pageNo", 0);
        retMap.put("pageRowNum", 0);
        retMap.put("totalRowNum", 0);
        retMap.put("totalPageNum", 0);

        return retMap;
    }

    int totalRowNum = list.size();
    int totalPageNum = (totalRowNum - 1) / pageSize + 1;

    int realPageNo = currPageNo;
    if (currPageNo > totalPageNum) {
        realPageNo = totalPageNum;
    } else if (currPageNo < 1) {
        realPageNo = 1;
    }

    int fromIdx = (realPageNo - 1) * pageSize;
    int toIdx = realPageNo * pageSize > totalRowNum ? totalRowNum : realPageNo * pageSize;   
    
    List result = list.subList(fromIdx, toIdx);

    retMap.put("result", result);
    retMap.put("pageNo", realPageNo);
    retMap.put("pageRowNum", result.size());
    retMap.put("totalRowNum", totalRowNum);
    retMap.put("totalPageNum", totalPageNum);

    return retMap;
}