JSP分页的实现

<%@ page contentType="text/html;charset=GB2312"%>
<%@ page import="java.sql.*"%>
<html>
<title>分页显示(jsp版)</title>
<body>

<%!  int pageSize = 5;//每页显示的记录数
     int pageCount = 0;//总页数
%>

<%
    Connection con;
    String DatabaseDriver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
    String CnnStr = "jdbc:microsoft:sqlserver://127.0.0.1:1433;databasename=Shopping";
    try {
        Class.forName(DatabaseDriver);
        con = DriverManager.getConnection(CnnStr, "sa", "11"); 
        Statement stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);//可滚动查询数据的结果集
        ResultSet rs =  stmt.executeQuery("select * from ProductInfo order by P_ID");
        rs.last(); //让游标到表中的最后一行
        int rowCount = rs.getRow(); //获取记录总数.
        //out.print("总记录数为"+rowCount);
        //总页数的计算公式
        pageCount = (rowCount % pageSize == 0) ? (rowCount / pageSize ) : (rowCount / pageSize +1);
        int showPage = 1;//当前页
%>



<%
    //取得用户所指定的页
    String goToPage = request.getParameter("showPage");
    if (goToPage == null){
        goToPage = "1";
    }
    
    //转换成整形
    try{
        showPage = Integer.parseInt(goToPage);
    }
    catch (NumberFormatException ex){
        showPage = 1;
    }
    
    //当前页小于等于第一页 则按第一页算 如果 当前页大于等于总页数则为最后页
    if(showPage <=1){
        showPage = 1;
    }
    else if(showPage >= pageCount){
        showPage =  pageCount;
    }
    
    //游标的位置 (当前页 - 1) * 页面大小 + 1
    int posion = (showPage -1 ) * pageSize + 1;
    //设置游标的位置 
    rs.absolute(posion);

%>


<table border="1" cellspacing="0" cellpadding="0"> 
<tr> 
<th>商品号</th> 
<th>商品名称</th> 
</tr> 
<%
   int i =0;
   //循环显示表中的数据 pageSize(每页所显示的记录)
   //rs.isAfterLast() 游标是否在最后一行之后 说明后面已经没记录
   while(i<pageSize && !rs.isAfterLast()){
%>
<tr> 
<td><%=rs.getString(1)%></td> 
<td><%=rs.getString(2)%></td> 
</tr> 
<%rs.next();i++;}%>
</table> 


<table width="624">
<form action="" method="get">   

<tr>
<td>
<%if(showPage < pageCount){%>
    <a href="Noname1.jsp?showPage=<%=showPage+1%>">[下一页]</a>
<%}%> 
</td>
<td><%if(showPage > 1){%>
    <a href="Noname1.jsp?showPage=<%=showPage-1%>">[上一页]</a>
    <%}%> 
</td>

<td> 共<%=pageCount%>页 </td>
<td> 第<%=showPage%>页  </td>
<td> <a href="Noname1.jsp?showPage=1">『首页』</a> </td>
<td> <a href="Noname1.jsp?showPage=<%=pageCount%>">『尾页』</a> </td>
<td> <%=rowCount%> </td>
<td>
  转到<input type="text" name="showPage" size="4"></input>
      <input type="submit" name="go" value="提交"></input>  
</td> 
</tr>
</form>
</table>
<% 
con.close(); 
}  catch (ClassNotFoundException e1) {out.print(e1.getMessage());}
    catch(SQLException e2){ out.print(e2.getMessage());}
%>
</body>
</html>