pageonebyone.java

这是一个ejb的基本程序

package bookSearchOrderBean;    //定义JavaBean所在的包

import java.sql.*;
import java.util.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class PageOneByOne
 {
  /* 这是一个实现记录结果集分页输出的JavaBean */

  public int TotalRecs = 0;     // 记录总数
  public int perPageRecs = -1;  // 每页显示的记录数
  public int TotalPages = -1;   // 页数总和
  public int CurrentPage = 1;   // 当前页数
  public String PageURL = null;
  public String PageIndex = null;
  DBexecuteBean dbexe = null;
  ResultSet rset;

  public PageOneByOne()
    {
     /* 定义构造器，初始化每页显示的主题数 */
     perPageRecs = 3;   // 每页显示3条数据
     dbexe = new DBexecuteBean();
    }

  public ResultSet procPagesAndRecords(int TotalRecords,String sSQLCmd,HttpServletRequest req) throws SQLException
    {
     /* 这个方法（函数）是用来计算总的页数 */
     PageURL = req.getRequestURI();     //获取当前的连接
     PageIndex = req.getParameter("pages");
     if((PageIndex == null) || (PageIndex.length() < 1))
       {
        /* 定义当前页数 */
        CurrentPage = 1;
       }       
     else
       {
        CurrentPage = Integer.parseInt(PageIndex);
        CurrentPage = (CurrentPage < 1) ? 1 : CurrentPage;
       }
     TotalRecs = TotalRecords;     // 获取记录结果集的总数
     TotalPages = (TotalRecs + perPageRecs + 1) / perPageRecs;  // 计算总的页数
     CurrentPage = (CurrentPage > TotalPages) ? TotalPages : CurrentPage;
     rset = dbexe.getTableRecords(sSQLCmd);
     return rset;
    }

  public int getTotalRecs()
    {
     /* 获取记录总数 */
     return TotalRecs;
    }

  public int getTotalPages()
    {
     /* 获取总的页数 */
     return TotalPages;
    }
  public int getCurrentPage()
    {
     /* 获取当前的页数 */
     return CurrentPage;
    }

  public String cutPage()
    {
     /* 这个方法（函数）是建立URL连接对象 */

     String URLlinkStr = "";            // URL连接串
     int prevPage = -1;
     int nextPage = -1;
     prevPage = CurrentPage - 1;        // 前一页
     nextPage = CurrentPage + 1;        // 后一页

     URLlinkStr += "<td><b><i>总共有" + getTotalRecs() + " 条记录，分" + getTotalPages() + "页显示，目前是第" + getCurrentPage() + "页。";
     if(CurrentPage > 1)
       {URLlinkStr += "<a href=" + PageURL + "?pages=1>首&nbsp;&nbsp;页</a>&nbsp;";}
     else
       {URLlinkStr += "首&nbsp;&nbsp;页&nbsp;";}
     if(CurrentPage > 1)
       {URLlinkStr += "<a href=" + PageURL + "?pages=" + prevPage + ">上一页</a>&nbsp;";}
     else
       {URLlinkStr += "上一页&nbsp;";}
     if(CurrentPage < TotalPages)
       {URLlinkStr += "<a href=" + PageURL + "?pages=" + nextPage + ">下一页</a>&nbsp;";}
     else
       {URLlinkStr += "下一页&nbsp;";}
     if((TotalPages > 1) && (TotalPages != CurrentPage))
       {URLlinkStr += "<a href=" + PageURL + "?pages=" + TotalPages + ">尾&nbsp;&nbsp;页</a>&nbsp;";}
     else
       {URLlinkStr += "尾&nbsp;&nbsp;页&nbsp;";}
     URLlinkStr += "</i></b></td>";

     return URLlinkStr;
    }
 }