servlet分页

采用servlet进行分页处理

Java代码

步骤：   

1.  创建SepPage类，并设置有关的方法。   

2.  在进行页面的转移时传递并当前的页面并传递参数。   

3.  进行分页处理。   

a.  计算总记录数   

b.  怎么样进行分页   

c.  首页显示处理   

d.  传递有关参数   

e.  获取有关传递的页面的参数   

 

  

实例：以查询所有的用户信息为例子进行说明   

  

 package bean;
 /**********************分页类描述************************/
 public class SepPage
{
     private int allRows; // 一共有多少行记录
     private int curPage = 1; // 当前页面
     private int rowPerPage = 8; // 一页显示多少行
     private int allPages; // 一共有多少页
     public int getAllRows()
    {
         return allRows;
    }
     public void setAllRows(int allRows)
    {
         this.allRows = allRows;
    }
     public int getCurPage()
    {
         return curPage;
    }
     public void setCurPage(int curPage)
    {
         this.curPage = curPage;
    }
     public int getRowPerPage()
    {
         return rowPerPage;
    }
     public void setRowPerPage(int rowPerPage)
    {
         this.rowPerPage = rowPerPage;
    }
     public int getAllPages()
    {
         return allPages;
    }
     public void setAllPages(int allPages)
    {
         this.allPages = allPages;
    }
}


 2.数据接收servlet
 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 bean.DBOperationBean;
 import java.util.*;
 import util.Convert;
 import java.sql.*;
 import bean.*;
 /**
 * servlet类，获取有关客户的信息并进行相关的处理
 * @author qihuasun
 */
 public class CustomerServlet extends HttpServlet
{
     //查询所有sql语句
     public static final String SELECTBYALL="select * from SCOTT.EXRM_T_CUSTOMER order by CUM_FULLNAME ";
     public void doGet(HttpServletRequest request, HttpServletResponse response)
     throws ServletException, IOException
    {
          this.doPost(request, response);
     }
     public void doPost(HttpServletRequest request, HttpServletResponse response)
     throws ServletException, IOException
    {
         //处理有关中文乱码问题
         request.setCharacterEncoding("GBK");
         response.setContentType("text/html;charset=GBK");
         response.setCharacterEncoding("GBK");
         String status=request.getParameter("status").trim();//获取页面传递的标志位status
         String path="error.jsp";
          if(!status.equals("")|| status!=null)
         {

            if(status.equals("findall"))
          {
                DBOperationBean db=new DBOperationBean();
               String page=request.getParameter("curpage");
                try
                {
                    int curPage = Integer.parseInt(request.getParameter("curPage"));
 //获取页面传递的参数
                     SepPage pa=new SepPage();
                    pa.setCurPage(curPage);
                     ArrayList al=db.query(this.SELECTBYALL,pa);
                     if(al!=null)
                     {
                         // path="main.jsp";
                           path="TestMain2.jsp";
                           request.setAttribute("all",al);
                     }
                     else
                    {
                         path="error.jsp";
                    }

                }
                 catch(Exception ex)
                {
                    ex.printStackTrace();
                }
          }

         }
         request.getRequestDispatcher(path).forward(request,response);

    }

}

 4.  数据访问类
  package bean;
 import java.sql.*;

 import javax.sql.*;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.naming.*;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.NodeList;
 import java.util.*;
 import bean.SepPage;
 /**
 * bean类，获取有关配置文件的信息的页面的信息，并进行有关的处理
 * @author qihuasun
 */
 public class DBOperationBean
{
      //驱动
    private final String DBDRIVER    = "oracle.jdbc.driver.OracleDriver";
    // 数据库连接地址
    private final String DBURL       = "jdbc:oracle:thin:@127.0.0.1:1521:data";
     // 数据库用户名
    private final String DBUSER      = "SCOTT";
     // 数据库连接密码
    private final String DBPASSWORD  = "sqh";
     // 声明一个数据库连接对象
    private Connection conn              = null ;
    private PreparedStatement  pstm=null;
    private ResultSet rs=null;
    public DBOperationBean()
   {
        this.init();
   }
     private void init()  //从数据库连接属性XML配置文件中获取关于连接的信息
    {
         conn=new DBConnection().getConnection();
    }
     private Connection getConnection() //取得数据库连接并设置为当前连接
    {
          try
         {
              Class.forName(DBDRIVER);

               conn = DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD);// 连接数据库
               System.out.println("connected");
         }
          catch(Exception ex)
         {
             ex.printStackTrace();
         }


         return this.conn;
    }

     public ArrayList query(String sql,SepPage page) throws Exception
     {//执行查询，返回结果集
         ArrayList al=new ArrayList();
         try
        {
             Connection conn=this.getConnection();
            pstm = conn.prepareStatement(sql, ResultSet.TYPE_SCROLL_INSENSITIVE,
                    ResultSet.CONCUR_READ_ONLY);
            rs=pstm.executeQuery();
             rs.last(); // 移动到最后一行
             page.setAllRows(rs.getRow()); // 设置一共有多少行记录
             // 算出有多少页
             if (page.getAllRows() % page.getRowPerPage()== 0)
            {
                page.setAllPages(page.getAllRows() / page.getRowPerPage());
            }
             else
            {
                 page.setAllPages(page.getAllRows() / page.getRowPerPage() + 1);
            }
             //判定是否是第一页
             if (page.getCurPage() == 1) //当前页
            {
                 // 将指针移动到此ResultSet对象的开头,正好位于第一行之前
                rs.beforeFirst();
            }
             else
            {
                 // 将指针移动到此ResultSet对象的给定行编号
                 rs.absolute((page.getCurPage() - 1) * page.getRowPerPage());
            }
             int i = 0;
             while(rs.next() && i < page.getRowPerPage())
            {
                  Customer cu=new Customer();
                  cu.setId(rs.getInt("CUM_ID"));
                  cu.setName(rs.getString("CUM_FULLNAME"));
                  cu.setAddress(rs.getString("CUM_MAINADDRESS"));
                  cu.setPhone(rs.getString("CUM_PHONE"));
                 al.add(cu);
                 i++;
            }
        }
         catch(Exception ex)
        {
             ex.printStackTrace();
        }
         finally
        {
                try
               {
                    if(conn!=null)
                   {
                        this.conn.close();
                   }
               }
                catch(Exception ex)
               {
                   ex.printStackTrace();
               }
        }
         return al;
    }
}

 4、页面显示
   <%@ page language="java" contentType="text/html;charset=GBK"%>
 <%@ page import="java.util.*,bean.SepPage"%>
 <%@page import="bean.Customer;"%>

<%
     ArrayList all = (ArrayList) request.getAttribute("all");
     SepPage seppage = (SepPage) request.getAttribute("pagebean");
 //获取设置的SepPage参数
%>
 "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3c.org/TR/1999/REC-html401-19991224/loose.dtd">
 "http://www.w3.org/1999/xhtml">

        客户管理
         "css/style.css" rel="stylesheet" />


         class="top" >
            『 作者管理 』

  

        class="center">   

            "AuthorServlet?status=selectbylike&curPage=1" method="post" style="margin: 0;">   

                class="fine" cellpadding="0" cellspacing="0">   

                       

                        "3" style="height: 40px;">   

  

                           

                        

                       

                          

                              序号   

                           

                           

                            客户名称   

                           

                           

                            联系电话   

                           

                               

                            地址   

                           

                               

                            操作   

                           

                       

                    <%   

                        int i=0;   

                        if (all != null && all.size() != 0)   

                         {   

                            for (int j=0;j

                            {     

                                i++;   

                                Customer cus=(Customer)all.get(j);   

                                int authorId1=cus.getId();   

                                String str="找不到记录！！！";   

                                if(i==0)   

                                {    

                                       

                                      

                                   out.println("alert('找不到记录')