java 分页

浏览数：26 / 时间：2015年06月08日

ListAction.java

package com.sy.action;

import java.util.List;

import com.opensymphony.xwork2.ActionSupport;
import com.sy.dao.AdminDao;
import com.sy.dao.NewsDao;
import com.sy.dao.impl.AdminDaoImpl;
import com.sy.dao.impl.NewsDaoImpl;
import com.sy.vo.Admin;
import com.sy.vo.News;

public class ListAction extends ActionSupport {

    private static final long serialVersionUID = 1L;
        int i=1;//中间变量
    private int k;//储存最大页面数
    private int pageNow=1; //页码数,初始为1
    private int pageSize = 5 ; //页面行数
    private int intRowCount;//总行数
    private int intPageCount;//总页数
    private Admin admin;
    private List<Admin> Adminss;
    private News news;
    @SuppressWarnings("unchecked")
    private List<News> Newss;

    private int id;
    private int aid;

    public News getNews() {
        return news;
    }

    public void setNews(News news) {
        this.news = news;
    }

    @SuppressWarnings("unchecked")
    public List<News> getNewss() {
        return Newss;
    }
    public void setNewss(List<News> newss) {
        Newss = newss;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }
    public Admin getAdmin() {
        return admin;
    }

    public void setAdmin(Admin admin) {
        this.admin = admin;
    }

    public List<Admin> getAdminss() {
        return Adminss;
    }

    public void setAdminss(List<Admin> adminss) {
        Adminss = adminss;
    }
    public int getAid() {
        return aid;
    }

    public void setAid(int aid) {
        this.aid = aid;
    }

    public int getPageNow() {
        return pageNow;
    }

    public void setPageNow(int pageNow) {
        this.pageNow = pageNow;
    }

    public int getPageSize() {
        return pageSize;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }
    public int getIntRowCount() {
        return intRowCount;
    }

    public void setIntRowCount(int intRowCount) {
        this.intRowCount = intRowCount;
    }

    public int getIntPageCount() {
        return intPageCount;
    }

    public void setIntPageCount(int intPageCount) {
        this.intPageCount = intPageCount;
    }
    public int getK() {
        return k;
    }

    public void setK(int k) {
        this.k = k;
    }
@SuppressWarnings("unchecked")
    @Override
//显示新闻列表
    public String execute() throws Exception {

        NewsDao npage=new NewsDaoImpl();
        intRowCount=npage.count();
        k=(intRowCount + pageSize - 1) / pageSize;
        intPageCount = (intRowCount + pageSize - 1) / pageSize;//计算出总页数
        if(pageNow<1){
            pageNow=1;
        }

        if(pageNow > intPageCount)
             pageNow=intPageCount;
             i = (pageNow -1)*pageSize;
        NewsDao nlist=new NewsDaoImpl();
        if(null!=nlist.queryByPage(i,pageSize)){
        Newss = nlist.queryByPage(i,pageSize);
            return SUCCESS;
        }else{
            return "failure";
        }
    }
          ..
}

listNews.jsp

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%
    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 ‘index.jsp‘ starting page</title>
    </head>
    <body>

..

        <center>
        共<s:property value="intRowCount"/>记录
        第<s:property value="pageNow"/>页
         <s:url id="url_pre" value="list.action">
         <s:param name="pageNow" value="pageNow-1"></s:param>
     </s:url>

     <s:url id="url_next" value="list.action">
         <s:param name="pageNow" value="pageNow+1"></s:param>
     </s:url>
     <s:iterator value="Newss" status="status">
        <s:url id="url" value="list.action">
            <s:param name="pageNow" value="pageNow"/>
        </s:url>
     </s:iterator>
     <s:if test="pageNow==1">
    <s:a href="%{url_pre}">最前一页</s:a>
     </s:if>
     <s:else>
     <s:a href="%{url_pre}">上一页</s:a>
     </s:else>
     <s:if test="pageNow==k">
     <s:a href="%{url_next}">最后一页</s:a>
       </s:if>
       <s:else>
       <s:a href="%{url_next}">下一页</s:a>
       </s:else>
       </center>
    </body>
</html>

NewsDao.java

package com.sy.dao.impl;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;

import com.sy.dao.NewsDao;
import com.sy.util.DataBaseConnection;
import com.sy.util.StringUtil;
import com.sy.vo.News;

public class NewsDaoImpl implements NewsDao {


        //获取分页新闻列表
    @SuppressWarnings("unchecked")
    public List<News> queryByPage(int i,int pageSize){
        List<News> newss=new ArrayList();

        PreparedStatement pstmt    = null ;
        String sql                = null ;
        ResultSet rs            = null ;
        DataBaseConnection dbc    = null ;
        dbc = new DataBaseConnection() ;

        sql = "select * from struts2new order by id asc limit " + i + "," + pageSize;
        try
        {

            pstmt = dbc.getConnection().prepareStatement(sql);

            rs = pstmt.executeQuery() ;
            while(rs.next())
            {
                News news=new News();
                news.setId(rs.getInt("id"));
                news.setName(rs.getString("name"));
                news.setTitle(rs.getString("title"));
                news.setDate(rs.getString("date"));
                news.setEmail(rs.getString("email"));
                news.setContent(rs.getString("content"));
                i++;
                newss.add(news);
            }
            rs.close() ;
            pstmt.close() ;
        }
        catch(Exception e)
        {
            System.out.println(e) ;
        }
        finally
        {
            dbc.close();
        }
        return newss;
    }
             //查询总行数
    public int count() {
        int intRowCount = 0;//总行数
        PreparedStatement pstmt    = null ;
        String sql                = null ;
        ResultSet rs            = null ;
        DataBaseConnection dbc    = null ;
        dbc = new DataBaseConnection() ;

        sql = "select count(id) from struts2new order by id asc";
        try
        {
            pstmt = dbc.getConnection().prepareStatement(sql);
            rs = pstmt.executeQuery();
            rs.next();//游标指向第一行
            intRowCount=rs.getInt(1);//取得总行数
            rs.close() ;
            pstmt.close() ;
        }
        catch(Exception e)
        {
            System.out.println(e) ;
        }
        finally
        {
            dbc.close();
        }
        return intRowCount;
    }
}