package framework.mybatis.pageAction;

import javax.servlet.http.HttpServletRequest;

public class PageInfo {
	public final static String REQUEST_ATTRIBUTE_PAGE_INFO = "REQUEST_ATTRIBUTE_PAGE_INFO";
	
	public final static int DEFAULT_COUNT_PER_PAGE = 10;
	
	private int page = 1;
	private int countPerPage = DEFAULT_COUNT_PER_PAGE;
	private int totalCount;
	private int startRow;
	private int endRow;
	private int totalPage;
	
	protected HttpServletRequest request;
	
	protected PageInfo(){
		
	}
	/**
	 * 设置总条数，计算分页参数
	 * 
	 * @param totalCount
	 * @param countPerPage
	 * @param page
	 */
	public void setTotalCount(int totalCount){
		this.totalCount = totalCount;
		
		if (this.totalCount % this.countPerPage == 0) {
			totalPage = (int) (this.totalCount / this.countPerPage);
		} else {
			totalPage = (int) (this.totalCount / this.countPerPage) + 1;
		}
		if(totalPage==0){
			totalPage = 1;
		}
		if(this.page<1){
			this.page=1;
		}
		if(this.page>totalPage){
			this.page=totalPage;
		}
		if (this.totalCount == 0) {
			startRow=0;
			endRow=0;
		}else{
			startRow=this.countPerPage*(this.page-1)+1;
			endRow = this.countPerPage * this.page;
			endRow = endRow > this.totalCount ? this.totalCount : endRow;
		}

		//save to request
		request.setAttribute(REQUEST_ATTRIBUTE_PAGE_INFO, this);
		request.setAttribute("pageSearchStartRow", Integer.valueOf(startRow));

	}
	
	/**
	 * 得到总页数
	 * @return
	 */
	public int getTotalPage(){
		return totalPage;
	}
	/**
	 * 得到当前页数
	 * @return
	 */
	public int getPage() {
		return page;
	}
	/**
	 * 得到每页多少条
	 * @return
	 */
	public int getCountPerPage() {
		return countPerPage;
	}
	/**
	 * 得到总条数
	 * @return
	 */
	public int getTotalCount() {
		return totalCount;
	}
	/**
	 * 得到开始的行数，从第1行开始，如果没有，则为0
	 * @return
	 */
	public int getStartRow() {
		return startRow;
	}
	/**
	 * 得到结束行数，从第1行开始，如果没有，则为0
	 * @return
	 */
	public int getEndRow() {
		return endRow;
	}

	/**
	 * 设置当前页数
	 * @param page
	 */
	public void setPage(int page) {
		if(page <1){
			page = 1;
		}
		this.page = page;
	}
	/**
	 * 设置每页条数
	 * @param countPerPage
	 */
	public void setCountPerPage(int countPerPage) {
		if(countPerPage<1){
			countPerPage = 1;
		}
		this.countPerPage = countPerPage;
	}

}