jsp 分页查询

刚刚学习jsp，谢了一个oracle数据库分页查询的代码

<%
int pageSize = 3;
int rowCount = 0;
int pageCount = 0;
int pageNow = 1;
int beginum=1;
int endnum=0;
%>

<%
Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
String url = "jdbc:oracle:thin:@localhost:1521:orcl";
//为你的数据库的SID
String user = "foking";
String password = "foking";
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
String sql = "select count(*) from t_warehousing";
ResultSet rs = stmt.executeQuery(sql);
if (rs.next()) {
rowCount = rs.getInt(1);
endnum=rowCount;
}
if (rowCount % pageSize == 0) {
pageCount = rowCount / pageSize;
} else {
pageCount = rowCount / pageSize + 1;
}

String s_pageNow = request.getParameter("pageNow");

if(s_pageNow!=null)
{ pageNow =Integer.parseInt(s_pageNow);}
// 判断页面的返回值
if( pageNow>rowCount/pageSize && rowCount % pageSize == 0)
{pageNow=rowCount/pageSize;
}else if(pageNow>rowCount/pageSize && rowCount % pageSize != 0){
pageNow=rowCount/pageSize+1;
}
else if( pageNow<=0) //当前页面小于等于0是则为第一页
{pageNow=1;
}
beginum=(pageNow-1)*pageSize+1;
System.out.println("pageNow:"+pageNow);
System.out.println("pageSize:"+pageSize);
endnum=(pageNow*pageSize);
rs=stmt.executeQuery("select * from (select  a.* ,rownum rnum from (select  *  from t_warehousing )a where rownum<="+pageSize*pageNow +") b where b.rnum>="+((pageNow-1)*pageSize+1) +"");

%>
<table border="1">
<tr>
<td>id号</td>
<td>产品名称</td>
<td>产品数量</td>
</tr>
<%
while(rs.next()) {
%>
<tr>
<td><%=rs.getInt(1)%></td>
<td><%=rs.getString(2)%></td>
<td><%=rs.getString(3)%></td>
<td><a href="delete.jsp?id=<%=rs.getInt(1)%>">删除</a></td>
<td><a href="update.jsp?id=<%=rs.getInt(1)%>">更新</a></td>
</tr>
<%
}
%>
</table>
<%
rs.close();
stmt.close();
conn.close();
%>
<br>
总页数:
<%=pageCount%>页
<br>
<br>
每页显示数据:
<%=pageSize%>条
<br>
当前页数为:第<%=pageNow%>页
<br>

总数为:<%=rowCount%>条<br>
<%out.println("<a href=testpagnation.jsp>首页</a>"); %>
<%out.println("<a href=testpagnation.jsp?pageNow="+(pageNow-1)+">上一页</a>"); %>
<%
for (int i = 1; i <= pageCount; i++) {
%>
<%
out.println("<a href=testpagnation.jsp?pageNow="+i+">" +i+"</a>");
%>
<%
}
%>
<%out.println("<a href=testpagnation.jsp?pageNow="+(pageNow+1)+">下一页</a>"); %>
<%out.println("<a href=testpagnation.jsp?pageNow="+pageCount+">末页</a>"); %>