需求：
每页列表下都有一个分页的功能，显示总数量、当前页/总页数、首页、上一页、下一页、最后一页、GO到第几页
效果动态图：
实现思路：
因为每个列表页都需要，在每个出列表页数据的servlet中都要求出总数量、当前页、总页数、结果list这几个值，那么我就把这些变量封装到一个基本实体类中，然后在service实现类中去求出这些变量的算法，那么我servlet执行时候，只用获取页面当前页的值，就可以算出所有变量的值。说的有点不清晰，那么我们直接上代码吧！
首先我们先看一下JSP的页面结构：
列表页newsDetailList.jsp:
底部调用公共分页的jsp
<!--隐藏域，当前页码 -->
<input type="hidden" id="pageIndex" name="pageIndex" value="1"/>
<input type="hidden" id="totalPageCount" name="totalPageCount" value="${totalPageCount }"/>
<c:import url="rollPage.jsp">
<c:param name="totalCount" value="${totalCount }"></c:param>
<c:param name="currentPageNo" value="${currentPageNo }"></c:param>
<c:param name="totalPageCount" value="${totalPageCount}"></c:param> </c:import>
上面当前页的设置为隐藏域，只是为了获取当前在第几页这个数据，用来算出其它几个值。
totalPageCount的隐藏域是为了执行输入页面GO到相应页的操作
看一下rollPage.jsp：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
<script type="text/javascript">
function page_nav(frm,num){
frm.pageIndex.value=num;
frm.submit();
} function go(frm,pageno){
//var regexp=/^\d+$/;
var regexp=/^[1-9]\d*$/;
var totalPage = document.getElementById("totalPageCount").value;
if(!regexp.test(pageno)){
alert("请输入 正确的数字！");
return false;
}else if((pageno-totalPageCount) > 0){
alert("总页码一共"+totalPageCount+"页，请输入正确的页码！");
return false;
}else{
page_nav(frm,pageno);
} } </script>
</head> <body> <div class="page-bar">
<ul class="page-num-ul clearfix">
<li>共${param.totalCount}条记录
${param.currentPageNo}/${param.totalPageCount }页</li>
<c:if test="${param.currentPageNo>1}">
<a href="javaScript:page_nav(document.forms[0],1)">首页</a>
<a
href="javaScript:page_nav(document.forms[0],${param.currentPageNo-1});">上一页</a>
</c:if>
<c:if test="${param.currentPageNo<param.totalPageCount}">
<a
href="javaScript:page_nav(document.forms[0],${param.currentPageNo+1});">下一页</a>
<a
href="javaScript:page_nav(document.forms[0],${param.totalPageCount });">最后一页</a>
</c:if>
</ul>
<span class="page-go-form"><label>跳转至</label> <input
type="text" name="inputPage" id="inputPage" class="page-key" value="" />页 <button type="submit" class="page-btn"
onclick='go(document.forms[0],document.getElementById("inputPage").value)'>GO</button> </span>
</div>
</body>
</html>
这个公共的分页，作用：控制分页界面的显示及提交到当前选择的页码
后端DAO实体类：
package com.cn.pb.dao.util; import java.sql.Connection;
import java.util.List; public class PageBase<M> {
//当前页码,默认为第1页
private int currentPageNo =1;
//总页数
private int totalPageCount;
//总记录数
private int totalCount;
//页面容量
private int pageSize=5;
//上一页
private int upPageNo;
//下一页
private int nextPageNo; //一页的结果
private List<M> list; public int getUpPageNo() {
return upPageNo;
}
public void setUpPageNo(int upPageNo) {
//如果当前页>1
if(this.currentPageNo>1){
this.upPageNo = this.currentPageNo-1;
} }
public int getNextPageNo() {
return nextPageNo;
}
public void setNextPageNo(int nextPageNo) {
//如果当前页>0且小于总页数，则可以有下一页
if(this.currentPageNo>0 &&this.currentPageNo<this.totalPageCount){
this.nextPageNo = currentPageNo+1;
} }
public List<M> getList() {
return list;
}
public void setList(List<M> list) {
this.list = list;
}
public int getCurrentPageNo() {
return currentPageNo;
}
//如果当前页码大于0才设置当前页码值
public void setCurrentPageNo(int currentPageNo) {
if(currentPageNo>0){
this.currentPageNo = currentPageNo;
} } public int getTotalCount() {
return totalCount;
}
public void setTotalCount(int totalCount) {
if(totalCount>0){
this.totalCount = totalCount;
} }
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
if(pageSize >0){
this.pageSize = pageSize;
} } public int getTotalPageCount() {
return totalPageCount;
}
public void setTotalPageCount(int totalPageCount) {
if(this.getTotalCount()%this.pageSize==0){
this.totalPageCount = this.getTotalCount()/this.pageSize;
}else if(this.getTotalCount()%this.pageSize>0){
this.totalPageCount = this.getTotalCount()/this.pageSize +1 ;
}else{
this.totalPageCount =0;
}
} /*//设置总页数
public void setTotalPageCount(int ) {
if(this.getTotalCount()%this.pageSize==0){
this.totalPageCount = this.getTotalCount()/this.pageSize;
}else if(this.getTotalCount()%this.pageSize>0){
this.totalPageCount = this.getTotalCount()/this.pageSize +1 ;
}else{
this.totalPageCount =0;
} }
*/ }
service接口：
//分页和list独立出一个javabean
public PageBase<NewsDetail> getPages(int pageNo,String where);
service实现类：
public PageBase<NewsDetail> getPages(int pageNo,
String where) {
PageBase<NewsDetail> pb=new PageBase<NewsDetail>();
pb.setCurrentPageNo(pageNo);
pb.setTotalCount(this.getNewsCount(where));
pb.setTotalPageCount(pb.getTotalCount()/pb.getPageSize());
pb.setNextPageNo(pageNo-1);
pb.setUpPageNo(pageNo+1);
pb.setList(this.getPageNewsList(pageNo, pb.getPageSize(), where));
return pb;
}
web.xml
<servlet>
<servlet-name>newsListByLikeServlet</servlet-name>
<servlet-class>com.cn.pb.servlet.NewsListByLike3</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>newsListByLikeServlet</servlet-name>
<url-pattern>/servlet/newsListServlet</url-pattern>
</servlet-mapping>
其实也就是把我上一篇<JSP+Servlet+javabean实现页面多条件模糊查询>中servlet那部分分页和求结果list给抽出来封装了,好吧，我只是改了web.xml中的类名，其它地方啥都不用改。可以多个servlet切着来