数据库表格:
customer
分页的实现:
从数据库查询--总记录：totalRecords
自定义--每页显示多少条记录： pageSize
通过总记录数和页容量计算出来--总页数： totalPages ----(totalRecords%pageSize==0? totalRecords/pageSize : totalRecords/pageSize+1)
页面传递--当前页码: currentPage
从数据库查询--每页数据：List
通过当前页数和页容量计算出来--每页查询开始的索引 startIndex startIndex = (currentPage-1)*pageSize
bean
public class Page {
private long totalRecords;//总记录数 从数据库查询
private long pageSize=5;//每页显示多少条
private long totalPages;//总页数 计算出来
private long currentPage;//当前页码
private List list; //每页存放的数据 从数据库查询
private long startIndex;//每页开始查询的索引 计算出来
public Page(long currentPage,long totalRecords){
this.currentPage = currentPage;
this.totalRecords = totalRecords;
this.totalPages = (totalRecords%pageSize==0? totalRecords/pageSize : totalRecords/pageSize+1);
this.startIndex = (currentPage-1)*pageSize;
}
public long getTotalRecords() {
return totalRecords;
}
public void setTotalRecords(long totalRecords) {
this.totalRecords = totalRecords;
}
public long getPageSize() {
return pageSize;
}
public void setPageSize(long pageSize) {
this.pageSize = pageSize;
}
public long getTotalPages() {
return totalPages;
}
public void setTotalPages(long totalPages) {
this.totalPages = totalPages;
}
public long getCurrentPage() {
return currentPage;
}
public void setCurrentPage(long currentPage) {
this.currentPage = currentPage;
}
public List getList() {
return list;
}
public void setList(List list) {
this.list = list;
}
public long getStartIndex() {
return startIndex;
}
public void setStartIndex(long startIndex) {
this.startIndex = startIndex;
}
}
Dao.Impl
public class CustomerDaoImpl implements CustomerDao{
QueryRunner qr = new QueryRunner(C3p0Util.getDataSource());
//显示列表
public List<Customer> findCustomers() {
String sql = "select * from customer";
List<Customer> clist = new ArrayList<Customer>();
try {
clist = qr.query(sql, new BeanListHandler<Customer>(Customer.class));
} catch (SQLException e) {
e.printStackTrace();
}
return clist;
}
//查询每页记录数据
public List<Customer> findPageCustomers(long startIndex, long pageSize) {
String sql = "select * from customer limit ?,?";
Object[] params = {startIndex,pageSize};
List<Customer> clist = new ArrayList<Customer>();
try {
clist = qr.query(sql, new BeanListHandler<Customer>(Customer.class),params);
} catch (SQLException e) {
e.printStackTrace();
}
return clist;
}
//查询总记录数
public long findCustomersCount() {
String sql = "select count(1) from customer";
long i= 0;
try {
i = (Long)qr.query(sql, new ScalarHandler(1));
} catch (SQLException e) {
e.printStackTrace();
}
return i;
}
}
Service.Impl
public class CustomerServiceImpl implements CustomerService{
private CustomerDao dao = new CustomerDaoImpl();
//显示列表
public List<Customer> findCustomers() {
return dao.findCustomers();
}
//与页码相对应的每个列表
public Page findPage(long currentPage) {
long totalRecords = dao.findCustomersCount();//总记录数
Page page = new Page(currentPage, totalRecords);
List<Customer> clist = dao.findPageCustomers(page.getStartIndex(), page.getPageSize());
page.setList(clist);
return page;
}
}
Servlte(在web.xml里设置默认页面为servlte页面)
/**
* servlet页面
* @author Administrator
*下午1:56:49
*/
public class CustomerAction extends HttpServlet {
private CustomerService service = new CustomerServiceImpl();
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String currentPageStr = request.getParameter("pagenum"); //从网页上获取跳转的页数
int currentPage = 1; //默认显示第一页
if(currentPageStr!=null){
currentPage = Integer.parseInt(currentPageStr);
}
Page page = service.findPage(currentPage);//显示与页码相对应的列表
request.setAttribute("page", page);
request.getRequestDispatcher("WEB-INF/jsp/clist.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
jsp(由servlet处理后转发至jsp页面)
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>客户列表</title>
<c:set var="ctp" value="${pageContext.request.contextPath }"></c:set>
<script type="text/javascript" src="${ctp }/js/jquery-1.8.3.js"></script>
</head>
<body>
<h2>客户列表</h2>
<table border="1" width="80%">
<tr>
<th>序号</th>
<th>姓名</th>
<th>性别</th>
<th>生日</th>
<th>电话</th>
<th>邮箱</th>
<th>爱好</th>
<th>类型</th>
<th>描述</th>
</tr>
<c:forEach items="${page.list }" var="ct" varStatus="cs"> <!--使用迭代标签库 -->
<tr style="background-color: ${cs.count%2==0? ‘#E0FFFF‘:‘#EEE685‘}">
<td>${cs.count }</td>
<td>${ct.name }</td>
<td>${ct.gender==1? ‘男‘:‘女‘ }</td>
<td>${ct.birthday }</td>
<td>${ct.phone }</td>
<td>${ct.email }</td>
<td>${ct.hobby }</td>
<td>${ct.type }</td>
<td>${ct.description }</td>
</tr>
</c:forEach>
</table>
<p>
总记录数：${page.totalRecords }条
当前第${page.currentPage }页/共${page.totalPages }页
<a href="${ctp }/customerAction?pagenum=1">首页</a>
<a href="${ctp }/customerAction?pagenum=${page.currentPage-1<1? 1 : page.currentPage-1}">上一页</a>
<a href="${ctp }/customerAction?pagenum=${page.currentPage+1<page.totalPages? page.currentPage+1 : page.totalPages}">下一页</a>
<a href="${ctp }/customerAction?pagenum=${page.totalPages}">尾页</a>
<input id="num" placeholder="请输入整数"/><input type="button" id="btn" value="跳转"/>
<input id="pages" value="${page.totalPages }" type="hidden">
</p>
<!--使用jQuery简单判定跳转的页数是否合法-->
<script type="text/javascript">
$(function(){
$("#btn").click(function(){
var pageNum = Number($("#num").val());
var pages = Number($("#pages").val());
if(isNaN(pageNum)){
alert("请输入数字！");
return;
}
if(pageNum > pages){
alert("输入页码错误！");
return;
}
location.href = "${ctp}/customerAction?pagenum="+pageNum;
});
});
</script>
</body>
</html>
效果图:
注:省略dao层、service层、c3p0连接池工具包
时间： 2024-10-11 04:35:56