JSP分页简单例子

ㄗs-﹎呯倓 · 发表于 2009-9-15 02:57:31

复制代码 package servlet;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Database {

private static Statement stmt=null;
private static ResultSet rs=null;
private static Connection con;
private static Connection con1;
private static Database dbms;
public Database(){
      String url = "jdbc:sqlserver://";
      String serverName= "127.0.0.1";
      String portNumber = "1433";
      String databaseName= "db_cd";
      String userName = "dragon";
      String password = "123";
      try {
         Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
         con = DriverManager.getConnection(url+serverName+":"+portNumber+";"+"DatabaseName="+databaseName,userName,password);

      } catch(ClassNotFoundException e) {
         e.printStackTrace();
      } catch (SQLException e) {
         e.printStackTrace();
      }
}

public static void init_dbms(){
      if(dbms==null){
         dbms=new Database();
      }
}
public static Connection getcon(){
      return con;
}
public static ResultSet stmt_select(String sql){
      init_dbms();
      try {
         stmt=con.createStatement();
         rs=stmt.executeQuery(sql);

      } catch (SQLException e) {
         e.printStackTrace();

      }
      return rs;
}
public static boolean stmt_uporin(String sql){
      init_dbms();
      boolean f=false;
      try {
         stmt=con.createStatement();
         stmt.executeUpdate(sql);
         f=true;
      } catch (SQLException e) {
         e.printStackTrace();
         f=false;
      }
      return f;
}
public static Connection con()
{
   String url = "jdbc:sqlserver://";
      String serverName= "127.0.0.1";
      String portNumber = "1433";
      String databaseName= "db_cd";
      String userName = "dragon";
      String password = "123";
      try {
         Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
         con1 = DriverManager.getConnection(url+serverName+":"+portNumber+";"+"DatabaseName="+databaseName,userName,password);

      } catch(ClassNotFoundException e) {
         e.printStackTrace();
      } catch (SQLException e) {
         e.printStackTrace();
      }
return con1;

}


}

上面是一个数据库的单类
复制代码 <%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style type="text/css">

</style>
</head>

<body>
<ul class="STYLE1">
<li><span class="STYLE2"><a href="CDtype?name=6">最新影音</a></span></li>
<li class="STYLE2" ><a href="CDtype?name=1">北美影音</a></li>
<li class="STYLE2"><a href="CDtype?name=2">大陆影音</a></li>
<li class="STYLE2"><a href="CDtype?name=3">日韩影音</a></li>
<li class="STYLE2"><a href="CDtype?name=4">港台影音</a></li>
<li><span class="STYLE2"><a href="CDtype?name=5">怀旧影音</a></span></li>
</ul>
</body>
</html>

上面这个是简单树导航的页面

复制代码 package bean;

public class CDtypebean {
   int page;

public int getPage() {
      return page;
}

public void setPage(int page) {
      this.page = page;
}

}
上面这个是JAVABEAN 文件，很简单不详细说了

复制代码 package servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import bean.CDtypebean;

public class CDtype extends HttpServlet {

/**
   * Constructor of the object.
   */
public CDtype() {
      super();
}

/**
   * Destruction of the servlet. <br>
   */
public void destroy() {
      super.destroy(); // Just puts "destroy" string in log
      // Put your code here
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException {

      response.setContentType("text/html");
      if (request.getParameter("name") != null) {//接收left.jsp传递过来的请求参数
         int page = Integer.parseInt(request.getParameter("name"));//把值转化成INT型
         CDtypebean cdtypebean = new CDtypebean();//创建并初始化 JABABEAN对象
         cdtypebean.setPage(page);//把PAGE值存入到JAVABEAN里
         HttpSession session = request.getSession();//创建SESSION对象，并调用方法把
         session.setAttribute("name", cdtypebean);//把CDtypebean对象存到session里
         response.sendRedirect("FenPage.jsp");//跳转页面
      }

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException {

      response.setContentType("text/html");

}

/**
   * Initialization of the servlet. <br>
   *
   * @throws ServletException
   *          if an error occurs
   */
public void init() throws ServletException {
      // Put your code here
}

}
这个是SERVELET文件

复制代码 <%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<%@ page import="bean.FenPage"%>
<%@ page import="bean.CDtypebean"%>
<%@ page import="java.sql.*"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
         + request.getServerName() + ":" + request.getServerPort()
         + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
      <base href="<%=basePath%>">

      <title>My JSP 'FenPage.jsp' starting page</title>

      <meta http-equiv="pragma" content="no-cache">
      <meta http-equiv="cache-control" content="no-cache">
      <meta http-equiv="expires" content="0">
      <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
      <meta http-equiv="description" content="This is my page">
      

</head>

<body>
      <%
         int curpage = 1; //当前页
         int allpage = 0; //总页数
         int allrecord = 0; //总记录数
         int page_record = 5; //分页单位
         int pages = 0; //用户请求的页面
         int lick = 0;
         CDtypebean typebean = (CDtypebean) session.getAttribute("name");//取出session值，用CDtypebean对象接收
         lick = typebean.getPage();//取出值附给变量lick
         String countSQL = "select count(*) from  a where typeID="
                  + lick;//SQL语句，主要是用来查询表里数据的条数
         if (request.getParameter("page") != null) {
            pages = Integer.parseInt(request.getParameter("page"));
         }
         FenPage fenpage = new FenPage(pages, page_record, countSQL, lick);//调用FenPage构造函数，把当前页面值、页面单位、查询条数SQL语句、树导航传递过来的值传到FenPage.java类
         Vector vector = fenpage.Fenye();
         allrecord = Integer.parseInt(vector.get(0).toString());
         allpage = Integer.parseInt(vector.get(1).toString());
         curpage = Integer.parseInt(vector.get(2).toString());
         ResultSet rs = (ResultSet) vector.get(3);
      %>
      <%
         while (rs.next()) {
      %>

      <table border="1">
         <tr align="center">
            <td align="center" width="95">
                  <a href=""><%=rs.getString(2)%></a>
            </td>
            <td align="center" width="95"><%=rs.getString(3)%></td>
            <td align="center" width="95"><%=rs.getString(4)%></td>
            <td align="center" width="95"><%=rs.getString(5)%></td>
            <td>

            </td>
         </tr>
      </table>
      <%
         }
      %>
      <p align=center>
         <a href=FenPage.jsp?page=1> 首页 </a>
         <a href="FenPage.jsp?page=<%=curpage - 1%>"> 上一页 </a>
         <a href=FenPage.jsp?page= <%=curpage + 1%>> 下一页 </a>
         <a href=FenPage.jsp?page= <%=allpage%>> 尾页 </a> 共
         <%=allpage%>
         页数第
         <%=curpage%>
         页共
         <%=allrecord%>
         条记录每页显示
         <%=page_record%>
         条
      </p>

</body>
</html>

上面这个是页面文件

复制代码 package bean;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Vector;

import servlet.Database;

public class FenPage {
public int curPage;// 当前页面
public int maxPage;// 总共页面
public int countRows;// 总共页数
public int showRows;// 显示条数
public String SQL;// SQL语句
public String countSQL;// 计算条数SQL
public int lick;
Vector v;

public FenPage(int curPage, int showRows, String countSql, int l) {
      this.curPage = curPage;
      this.showRows = showRows;
      this.countSQL = countSql;
      this.lick = l;
}

public Vector Fenye() {
      int allpage = 0;
      int allrecord = 0;
      // 总记录数
      ResultSet rs0 = Database.stmt_select(countSQL);
      try {
         if (rs0.next()) {
            allrecord = rs0.getInt(1);
         }
      } catch (SQLException e) {
         e.printStackTrace();
      }
      // 总的页数
      allpage = (int) Math.ceil((allrecord + showRows - 1) / showRows);
      // 根据用户提交的请求页判断应该显示的当前页
      if (curPage > allpage) {
         curPage = allpage;
      } else if (curPage < 1) {
         curPage = 1;
      } else {
         curPage = curPage;
      }
      System.out.println("curPage" + curPage);
      // 得到符合条件页面的显示记录的结果集rs;
      SQL = "SELECT TOP "
            + showRows
            + " * FROM (SELECT ROW_NUMBER() OVER (ORDER BY ID) AS RowNumber,* FROM a  where  typeID="
            + lick + ") A WHERE RowNumber > " + showRows * (curPage - 1);

      rs0 = Database.stmt_select(SQL);
      // 声明一个容器实例vector
      Vector vector = new Vector();
      vector.add(0, new Integer(allrecord));
      vector.add(1, new Integer(allpage));
      vector.add(2, new Integer(curPage));
      vector.add(3, rs0);
      return vector;
}
}

上面这个是分页BEAN文件我觉得写分页还真要看看这文件，有点数据库分页算法，把语句放到SQL里多运行下
只要明白分页原理，其实分页想怎么写就怎么，我的代码虽然简陋，封装得不好，但对于初学来说，这应该是个好的例子，希望对需要的人有点帮助。

小滋 · 发表于 2010-3-6 10:05:04

够震撼！够创新！！

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