day48

web

图片上传

分页功能改造

//查询出总共有多少条新闻
int countNews();
public int countNews() {
	String sql="select count(*) from news_detail";
	Object[] params= {};
	rs=query(sql, params);
	int num=0;
	try {
		while(rs.next()) {
			num=rs.getInt(1);//获取当前字段的值
		}
	} catch (SQLException e) {
		e.printStackTrace();
	}
	return num;
}

//根据当前页码数和页面容量查询新闻数据(分页查询)

List<NewsDetail> getAllNewsByPage(int pageNo,int pageSize);
public List<NewsDetail> getAllNewsByPage(int pageNo, int pageSize) {
	//计算limit第一个参数值的公式:(pageNo-1)*pageSize
	String sql="select * from news_detail limit ?,?";
	Object[] params= {(pageNo-1)*pageSize,pageSize};
	rs=query(sql, params);
	List<NewsDetail> list=new ArrayList<NewsDetail>();
	try {
		while(rs.next()) {
			NewsDetail news=new NewsDetail();
			news.setAuthor(rs.getString("author"));
			news.setCategoryId(rs.getLong("categoryId"));
			news.setContent(rs.getString("content"));
			news.setCreateDate(rs.getDate("createDate"));
			news.setId(rs.getLong("id"));
			news.setModifyDate(rs.getDate("modifyDate"));
			news.setPicPath(rs.getString("picPath"));
			news.setSummary(rs.getString("summary"));
			news.setTitle(rs.getString("title"));
			list.add(news);
		}
	} catch (SQLException e) {
		e.printStackTrace();
	}
	return list;
}