jsp的分页查询

jsp页面步骤

1.定义页面位置input类型为hidden的隐藏域名称为pageIndex初始值为1
2.定义页面长度
3.通过请求获得参数的方法传入pageIndex得到pageIndex字符串
4.定义当前页面为1
5.进行页面位置的非空判断 (1)为空则值为1 (2)否则值为页面位置的包装类
6.定义总新闻数,通过实现类的getNewsCount()获得
7.创建分页类的对象
8.设置属性页面长度,当前页面,总新闻数,再通过分页对象的自定义方法得到总页数
9.进行判断:当前页为1以下时,或者大于总页数
10.定义总页数input类型为hidden的隐藏域名称为totalpagecount值为totalpagecont
11.通过c标签导入页面,同时用c标签的name,value属性传递三个参数,总新闻数,当前页码,总页数

接口

//获取新闻信息总数
public int getNewsCount();

//得到分页列表
public List<News> getPageNewsList(int pageNum,int pageSize);

实现类

@Override
public int getNewsCount() {
// TODO Auto-generated method stub
int count=0;
String sql="select count(*)as count from news_detail";
Object[] obj={};
if(this.getConnection()){
ResultSet rs=this.executeSQL(sql, obj);
try {
if(rs.next()){
count=rs.getInt("count");

}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
//释放资源
this.closeResource();
}
}
return count;

}

@Override
public List<News> getPageNewsList(int pageNum, int pageSize) {
// TODO Auto-generated method stub
List<News> newsList=new ArrayList<News>();
String sql="SELECT id,title,author,createDate FROM news_detail ORDER BY id ASC LIMIT ?,?";
pageNum=(pageNum-1)*pageSize;
Object[] params={pageNum,pageSize};
if(this.getConnection()){
ResultSet rs=executeSQL(sql, params);
try {
while(rs.next()){
News news=new News();
news.setId(rs.getInt("id"));
news.setTitle(rs.getString("title"));
news.setAuthor(rs.getString("author"));
news.setCreateDate(rs.getTimestamp("createDate"));
newsList.add(news);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
//释放资源
this.closeResource();
}
}
return newsList;
}

对象类

//总页数
private int totalpageCount=1;
//页面容量
private int pageSize=0;

//总记录数
private int totalCount=0;

//当前页码
private int currentPageNo=1;

public int getTotalpageCount() {
return totalpageCount;
}

public void setTotalpageCount(int totalpageCount) {
this.totalpageCount = totalpageCount;
}

public int getTotalCount() {
return totalCount;
}

public void setTotalCount(int totalCount) {
if(totalCount>0){
this.totalCount = totalCount;
this.setTotalPageCountByRs();
}
}

public int getCurrentPageNo() {
return currentPageNo;
}

public void setCurrentPageNo(int currentPageNo) {
if(currentPageNo>0)
this.currentPageNo = currentPageNo;
}

public int getPageSize() {
return pageSize;
}

public void setPageSize(int pageSize) {
if(pageSize>0)
this.pageSize = pageSize;
}

public void setTotalPageCountByRs(){
if(this.totalCount%this.pageSize==0){
this.totalpageCount=this.totalCount/this.pageSize;
}else if(this.totalCount%this.pageSize>0){
this.totalpageCount=this.totalCount/this.pageSize+1;
}else{
this.totalpageCount=0;
}
}

jsp页面

<%@page import="com.pb.news.entity.News"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@page import="com.pb.news.util.PageSupport"%>
<%@include file="../../common/common.jsp" %>
<script type="text/javascript">

function addNews(){
window.location="newsDetailCreateSimple.jsp";
}
function page_nav(frm,num){
frm.pageIndex.value=num;
frm.submit();
}
function jump_to(frm,num){
var regexp=/^[1-9]d*$/;
var totalpagecount= document.getElementById("totalpagecount");
if(!regexp.test(num)){
alert("输入正整数");
return false;
}else if(num>totalpagecount){
alert("超过总页数");
return false;
}else{
page_nav(frm,num);
}

}

</script>

<input type="hidden" name="pageIndex" value="1"/>

<%

//页面容量
int pageSize=5;

//当前页码
String pageIndex=request.getParameter("pageIndex");
int currentPageNo=1;
if(pageIndex==null){
currentPageNo=1;
}else{

try{
currentPageNo=Integer.parseInt(pageIndex);
}catch(NumberFormatException e){
response.sendRedirect("error.jsp");
}
}



//总记录数
int totalCount=newsService.getNewsCount();

//总页数
PageSupport pageSupport=new PageSupport();
pageSupport.setPageSize(pageSize);
pageSupport.setCurrentPageNo(currentPageNo);
pageSupport.setTotalCount(totalCount);
int totalpagecount=pageSupport.getTotalpageCount();
if(currentPageNo<1){
currentPageNo=1;
}
if(currentPageNo>totalpagecount){
currentPageNo=totalpagecount;
}



List<News> newsList=newsService.getPageNewsList(currentPageNo,pageSize);
int i=0;
for(News news:newsList){
i++;
%>
<tbody>
<input type="hidden" id="totalpagecount" name="totalpagecount" value=<%=totalpagecount %>/>
<tr <%if(i%2!=0){%>class="admin-list-td-h2"<%} %>>
<td><a href='adminNewsView.jsp?id=<%=news.getId() %>'><%=news.getTitle() %></a></td>
<td><%=news.getAuthor()%></td>
<td><%=news.getCreateDate() %></td>
<td><a href='adminNewsCreate.jsp?id=<%=news.getId() %>'>修改</a>
<a href="javascript:if(confirm('确认是否删除此新闻？')) location='adminNewsDel.jsp?id=<%=news.getId() %>'">删除</a>
</td>
</tr>
</tbody>
<%
}
%>

</table>
<div class="page-bar">
<ul class="page-num-ul clearfix">
<li>共<%=totalCount %></>条记录&nbsp;&nbsp; <%=currentPageNo%>/<%=totalpagecount %>页</li>
<%if(currentPageNo>1){%>
<a href="javascript:page_nav(document.forms[0],1)">首页</a>
<a href="javascript:page_nav(document.forms[0],<%=currentPageNo-1%>)">上一页</a>
<%}if(currentPageNo<totalpagecount){ %>
<a href="javascript:page_nav(document.forms[0],<%=currentPageNo+1%>)">下一页</a>
<a href="javascript:page_nav(document.forms[0],<%=totalpagecount%>)">最后一页</a>&nbsp;&nbsp;
<%} %>
</ul>
<span class="page-go-form"><label>跳转至</label>
<input type="text" name="inputPage" id="inputPage" class="page-key" />页
<button type="button" class="page-btn" onClick='jump_to(document.forms[0],document.getElementById("inputPage").value)'>GO</button>
</span>
</div>
</div>