com.mizhousoft.commons.data.util.PageUtils Maven / Gradle / Ivy

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package com.mizhousoft.commons.data.util;

import java.util.List;

import com.mizhousoft.commons.data.constant.PaginationConstants;
import com.mizhousoft.commons.data.domain.Pageable;

/**
 * 分页工具类
 *
 * @version
 */
public class PageUtils
{
	/**
	 * 计算行数偏移量
	 * 
	 * @param page
	 * @param total
	 * @return
	 */
	public static long calcRowOffset(Pageable pageRequest, long total)
	{
		if (0 == total)
		{
			return 0;
		}

		int pageSize = pageRequest.getPageSize();
		int pageNum = pageRequest.getPageNumber() - 1;
		long offset = pageSize * pageNum;
		if (offset < total)
		{
			return offset;
		}
		else
		{
			int num = (int) Math.ceil((double) total / (double) pageSize);
			if (num >= 1)
			{
				num = num - 1;
			}

			int rowOffset = num * pageSize;
			return rowOffset;
		}
	}

	/**
	 * 是否有更多数据
	 * 
	 * @param 
	 * @param list
	 * @return
	 */
	public static  boolean isNoMoreData(List list)
	{
		return isNoMoreData(list, PaginationConstants.SMALL_PAGE_SIZE);
	}

	/**
	 * 是否有更多数据
	 * 
	 * @param 
	 * @param list
	 * @param limitSzie
	 * @return
	 */
	public static  boolean isNoMoreData(List list, int limitSzie)
	{
		return list.size() < limitSzie;
	}
}