分页的基类
代码语言：javascript复制import java.util.List;
/**
分页显示的标准类,基本操作,是先给予-当前页数一共的数据条数-每页显示的条数,
然后在初始化该类,得到总共页数,和开始序号和结束序号,
然后数据库分页用到开始序号和结束序号,得到数据集合后赋值给该类的list属性,
然后把该类发送到jsp页面,进行访问
@author admin
*
@param <T>
*/
public class PageBean<T> {
private int pageIndex;//当前页数
private int pageSize;//一共的页数
private int count;//数据条数
private int pageCount;//每页的数据条数
private int start;//起始数据位置
private int end;//结束
private List<T> list=null;
public void init(){
/*根count 和pageCount计算页数pageSize
*/
int pageSize_x=(int)count/pageCount;
if(count>=pageCount){
this.pageSize=count%pageCount==0?pageSize_x:pageSize_x 1;
}else{
this.pageSize=1;
}
//判断页数和当前页数
if(pageIndex>pageSize){
pageIndex=pageSize;
}
if(pageIndex<1){
pageIndex=1;
}
//根据当前页计算起始和结束条目
this.start=(pageIndex-1)*pageCount 1;
this.end=pageIndex*pageCount;
}
public PageBean(int pageIndex, int count, int pageCount) {
super();
this.pageIndex = pageIndex;
this.count = count;
this.pageCount = pageCount;
}
public PageBean(int pageIndex, int count, int pageCount, List<T> list) {
super();
this.pageIndex = pageIndex;
this.count = count;
this.pageCount = pageCount;
this.list = list;
}
public PageBean() {
super();
// TODO Auto-generated constructor stub
}
@Override
public String toString() {
return "PageBean [count=" count ", end=" end ", list=" list
", pageCount=" pageCount ", pageIndex=" pageIndex
", pageSize=" pageSize ", start=" start "]";
}
public int getPageIndex() {
return pageIndex;
}
public void setPageIndex(int pageIndex) {
this.pageIndex = pageIndex;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public int getCount() {
return count;
}
public void setCount(int count) {
this.count = count;
}
public int getPageCount() {
return pageCount;
}
public void setPageCount(int pageCount) {
this.pageCount = pageCount;
}
public int getStart() {
return start;
}
public void setStart(int start) {
this.start = start;
}
public int getEnd() {
return end;
}
public void setEnd(int end) {
this.end = end;
}
public List<T> getList() {
return list;
}
public void setList(List<T> list) {
this.list = list;
}
}
</pre>
servlet调用
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.dao.MessageDao;
import com.dao.impl.MessageDaoImpl;
import com.vo.Message;
import com.vo.PageBean;
public class ShowMessageServlet extends HttpServlet{
/**
*
*/
private static final long serialVersionUID = 6646899131087204214L;
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doGet(req, resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
resp.setContentType("text/html;charset=utf-8");
int pageIndex=0;
MessageDao md=new MessageDaoImpl();
String pageIndexStr=req.getParameter("pageIndex");
if(pageIndexStr!=null){
try{
pageIndex=Integer.parseInt(pageIndexStr);
}catch (Exception e) {
}
}
PageBean<Message> pb=new PageBean<Message>(pageIndex,md.getMessageCount(),10);
pb.init();
pb.setList(md.getMessageListOfPage(pb.getStart(), pb.getEnd()));
req.setAttribute("pagebean", pb);
req.getRequestDispatcher("index.jsp").forward(req, resp);
}
}
</pre>
jsp页面的显示调用
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() "://" request.getServerName() ":" request.getServerPort() path "/";
%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<c:if test="${empty pagebean}">
<jsp:forward page="showmessage"></jsp:forward>
</c:if>
<body>
<c:forEach var="message" items="${pagebean.list}">
${message.title } ${message.editdate }<br/>
</c:forEach>
<a href="showmessage?pageIndex=${pagebean.pageIndex 1}">下一个</a>[${pagebean.pageIndex }<span>/</span>${pagebean.pageSize}]
</body>
</html>
</pre>
