分頁技術(shù)：將所有數(shù)據(jù)分段展示給用戶的技術(shù)。

分頁的意義：增加系統(tǒng)的復(fù)雜度，另外可以將大量的數(shù)據(jù)限制在某一個(gè)特定的范圍。

選擇分頁的標(biāo)準(zhǔn)：

?首先，判斷的標(biāo)準(zhǔn)是速度,顯而易見,數(shù)據(jù)庫服務(wù)器,Web應(yīng)用服務(wù)器和客戶端之間是網(wǎng)絡(luò),如果網(wǎng)絡(luò)傳遞的數(shù)據(jù)量越少,則客戶端獲得響應(yīng)的速度越快。一般來說,數(shù)據(jù)庫服務(wù)器和Web應(yīng)用服務(wù)器的處理能力一般比客戶端要強(qiáng)很多.從這兩點(diǎn)來看,在客戶端分頁的方案是最不可取的。

?其次，在Web服務(wù)器端分頁和在數(shù)據(jù)庫端分頁,如果選擇在Web服務(wù)器端分頁的話,大部分的被過濾掉的數(shù)據(jù)還是被傳輸?shù)搅薟eb應(yīng)用服務(wù)器端,與其這樣還不如直接在數(shù)據(jù)庫端進(jìn)行分頁。

?因此比較好的分頁做法應(yīng)該是每次翻頁的時(shí)候只從數(shù)據(jù)庫里檢索頁面大小的塊區(qū)的數(shù)據(jù)。

?雖然每次翻頁都需要查詢數(shù)據(jù)庫，但查詢出的記錄數(shù)很少，網(wǎng)絡(luò)傳輸數(shù)據(jù)量不大，如果使用連接池更可以略過最耗時(shí)的建立數(shù)據(jù)庫連接過程。而在數(shù)據(jù)庫端有各種成熟的優(yōu)化技術(shù)用于提高查詢速度，比在應(yīng)用服務(wù)器層做緩存有效得多。

?Web服務(wù)器端分頁和在數(shù)據(jù)庫端分頁：

?數(shù)據(jù)庫端分頁：通過JDBC的方式訪問數(shù)據(jù)庫，根據(jù)數(shù)據(jù)庫類型采取不同的SQL分頁語句。

? ?對(duì)于MySql數(shù)據(jù)庫：采用limit m,n語句進(jìn)行分頁，需要指定m和n的2個(gè)值

? ? ?Limit后的兩個(gè)參數(shù)中，參數(shù)m是起始下標(biāo)[頁碼]，它從0開始；參數(shù)n是返回的記錄數(shù)。?

? ? SQL語句形式： ?

??語句1:?select?*?from?表名?limit?m,n;?--返回表中m-n行的數(shù)據(jù)語句2:?select?*?from?表名?limit?m?offset?n;?--從n行開始到返回表中m行的數(shù)據(jù)假設(shè)?numberpage?表示每頁要顯示的條數(shù),pagenumber表示頁碼:語句3：select?*?from?表名?limit?(pagenumber-1)*numberpage,numberpage;語句4：select?*?from?表名?limit?numberpage?offset(pagenumber-1)*numberpage;

? ?對(duì)于Oracle數(shù)據(jù)庫：采用rownum的方式進(jìn)行分頁,rownum表示一條記錄的行號(hào),注意Oracle獲取每一行后才賦予.因此,指定rownum區(qū)間來取得分頁數(shù)據(jù)在一層查詢語句中是無法做到的,要分頁還要進(jìn)行一次查詢。

? ?SQL形式：

???select?*?from?(select?page.*,rownum?rn?from?(select?*?from?表名)?page?where?rownum?<=?(?-1)*?+?)where?rn?>?(?-1)*?;--其中page是將表中的數(shù)據(jù)查詢出來取名為page

另外,不論使用哪種數(shù)據(jù)庫，都的想知道數(shù)據(jù)中有幾條數(shù)據(jù)，自然需要一個(gè)獲取總行的SQL：

? ?SQL形式：

????select?count(*)?from?表名;

首先：實(shí)現(xiàn)分頁的具體實(shí)現(xiàn)需要結(jié)合JDBC和Java代碼實(shí)現(xiàn)：

? 分頁的時(shí)，返回的參數(shù)包括查詢的結(jié)果集(List)，總的頁數(shù)(pageCount)、當(dāng)前第幾頁(pageNo)等等信息，所以我們封裝一個(gè)查詢結(jié)果Page類，當(dāng)然還需要分頁的一個(gè)實(shí)體類，這里我以Entity為例，具體代碼：

Page.java: //第一種實(shí)現(xiàn)方式： import?java.util.List; import?entity.Entity; public?class?Page?{private?int?pageNo;//當(dāng)前頁數(shù)private?int?hangCount;//每頁顯示的行數(shù)private?int?sumCount;//總條數(shù)private?int?sumPage;//總頁數(shù)private?List<Entity>??entitys;//需要生成setXX()和getXX()方法public?int?getPageNo()?{return?pageNo;}public?void?setPageNo(int?pageNo)?{//給當(dāng)前頁賦值if?(pageNo<=1)?{this.pageNo=1;}else?if?(pageNo>=this.sumPage)?{this.pageNo=this.sumPage;}else?{this.pageNo?=?pageNo; }}public?int?getHangCount()?{return?hangCount;}public?void?setHangCount(int?hangCount)?{this.hangCount?=?hangCount;}public?int?getSumCount()?{return?sumCount;}public?void?setSumCount(int?sumCount)?{this.sumCount?=?sumCount;if(this.sumCount%this.hangCount==0){this.sumPage?=?this.sumCount/this.hangCount;}else{this.sumPage?=?this.sumCount/this.hangCount+1;}}public?int?getSumPage()?{return?sumPage;}public?void?setSumPage(int?sumPage)?{this.sumPage?=?sumPage;}//List<Entity>??entitys?生成的setXX()和getXX()方法} //第二種實(shí)現(xiàn)方式： import?java.util.List; import?entity.Entity; public?class?Page?{private?int?pageNo;//當(dāng)前頁數(shù)private?int?hangCount;//每頁顯示的行數(shù)private?int?sumCount;//總條數(shù)private?int?sumPage;//總頁數(shù)private?List<Entity>??entitys;//需要生成setXX()和getXX()方法public?int?getPageNo()?{return?pageNo;}public?void?setPageNo(int?pageNo)?{this.pageNo?=?pageNo;??}public?int?getHangCount()?{return?hangCount;}public?void?setHangCount(int?hangCount)?{this.hangCount?=?hangCount;}public?int?getSumCount()?{return?sumCount;}public?void?setSumCount(int?sumCount)?{this.sumCount?=?sumCount;setSumPage((getSumCount()%hangCount)==0?(getSumCount()/hangCount):(getTotalNum()?/hangCount+1));??}public?int?getSumPage()?{return?sumPage;}public?void?setSumPage(int?sumPage)?{this.sumPage?=?sumPage;}//?獲取首頁??public?int?getFirstPage()?{??return?1;??}??//?獲取末頁??public?int?getLastPage()?{??return?sumPage;??}??//?獲取上一頁??public?int?getPrePage()?{??if?(pageNo?>?1)??return?pageNo?-?1;??return?1;??}??//?獲取下一頁??public?int?getBackPage()?{??if?(pageNo<sumPage)??return?pageNo?+?1;??return?sumPage;??}??//?判斷'首頁'及‘上一頁’是否可用??public?String?isPreable()?{??if?(pageNo?==?1)??return?"disabled";??return?"";??}??//?判斷'尾頁'及‘下一頁’是否可用??public?String?isBackable()?{??if?(pageNo?==?totalPage)??return?"disabled";??return?"";??}?? //List<Entity>??entitys?生成的setXX()和getXX()方法 }

其次：編寫數(shù)據(jù)數(shù)據(jù)連接類，以BaseDao為例，具體代碼：

數(shù)據(jù)庫驅(qū)動(dòng)類名：oracle.jdbc.driver.OracleDriver

數(shù)據(jù)庫連接URL：jdbc:oracle:thin:@localhost:1521:連接名

數(shù)據(jù)庫用戶名和密碼：userName，passWord

//BaseDao.java 第一種方式： import?java.sql.Connection;?? import?java.sql.DriverManager;?? import?java.sql.PreparedStatement;?? import?java.sql.ResultSet;?? import?java.sql.SQLException;?? public?class?BaseDao{?//使用ThreadLocal是為了保證事務(wù)的一致，使得同一個(gè)線程的所有數(shù)據(jù)庫操作使用同一個(gè)Connection?private?static?ThreadLocal<Connection>?threadLocal?=?new?ThreadLocal<Connection>();??public?static?Connection?getConnection()?{??Connection?conn?=?null;??conn?=?threadLocal.get();??if?(conn?==?null)?{??try?{??Class.forName("數(shù)據(jù)庫驅(qū)動(dòng)類名");??conn?=?DriverManager.getConnection(??"數(shù)據(jù)庫連接URL",?"用戶名","密碼");??threadLocal.set(conn);??}?catch?(ClassNotFoundException?e)?{??e.printStackTrace();??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??return?conn;??}??//?封裝設(shè)置Connection自動(dòng)提交??public?static?void?setAutoCommit(Connection?conn,?Boolean?flag)?{??try?{??conn.setAutoCommit(flag);??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//?設(shè)置事務(wù)提交??public?static?void?commit(Connection?conn)?{??try?{??conn.commit();??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//?封裝設(shè)置Connection回滾??public?static?void?rollBack(Connection?conn)?{??try?{??conn.rollback();??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//?封裝關(guān)閉Connection、PreparedStatement、ResultSet的函數(shù)??public?static?void?closeConnection()?{??Connection?conn?=?threadLocal.get();??try?{??if?(conn?!=?null)?{??conn.close();??conn?=?null;??threadLocal.remove();??}??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//關(guān)閉PreparedStatementpublic?static?void?closePreparedStatement(PreparedStatement?pstmt)?{??try?{??if?(pstmt?!=?null)?{??pstmt.close();??pstmt?=?null;??}??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//關(guān)閉ResultSetpublic?static?void?closeResultSet(ResultSet?rs)?{??try?{??if?(rs?!=?null)?{??rs.close();??rs?=?null;??}??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//公共的增刪改方法public?int?allUpdateAndAddAndDel(List<Object>?list,String?sql){try?{conn=getConnection();ps=conn.prepareStatement(sql);if(list.size()>0){for?(int?i?=?0;?i?<?list.size();?i++)?{ps.setObject((i+1),?list.get(i));}}return?ps.executeUpdate();}?catch?(Exception?e)?{e.printStackTrace();return?-1;}finally{closeAll();}}//查詢公共方法public?ResultSet?select(String?sql,List<Object>?list)?{try?{conn=getConnection();ps=conn.prepareStatement(sql);if?(list.size()>0)?{for?(int?i?=?0;?i?<?list.size();?i++)?{ps.setObject((i+1),?list.get(i));}}rs=ps.executeQuery(); return?rs; }?catch?(Exception?e)?{e.printStackTrace();return?null; }} } 第二種方式：import?java.sql.Connection; import?java.sql.DriverManager; import?java.sql.PreparedStatement; import?java.sql.ResultSet; import?java.util.List;public?class?BaseDao?{private?String?name="用戶名";private?String?pwd="密碼";private?String?drivername="數(shù)據(jù)庫驅(qū)動(dòng)名";private?String?url="數(shù)據(jù)庫連接URL";public?Connection?conn?=?null;public?PreparedStatement?ps?=?null;public?ResultSet?rs?=?null;/***?關(guān)閉所有接口對(duì)象的方法*/public?void?closeAll(){try?{if(rs!=null)rs.close();if(ps!=null)ps.close();if(conn!=null)conn.close();}?catch?(Exception?e)?{e.printStackTrace();}}/***?獲取連接對(duì)象的方法*/public?Connection?getConnection(){try?{Class.forName(drivername);conn?=?DriverManager.getConnection(url,?name,?pwd);return?conn;}?catch?(Exception?e)?{e.printStackTrace();return?null;}}//?封裝設(shè)置Connection自動(dòng)提交??public?static?void?setAutoCommit(Connection?conn,?Boolean?flag)?{??try?{??conn.setAutoCommit(flag);??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//?設(shè)置事務(wù)提交??public?static?void?commit(Connection?conn)?{??try?{??conn.commit();??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//?封裝設(shè)置Connection回滾??public?static?void?rollBack(Connection?conn)?{??try?{??conn.rollback();??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//?封裝關(guān)閉Connection、PreparedStatement、ResultSet的函數(shù)??public?static?void?closeConnection()?{??Connection?conn?=?threadLocal.get();??try?{??if?(conn?!=?null)?{??conn.close();??conn?=?null;??threadLocal.remove();??}??}?catch?(SQLException?e)?{??e.printStackTrace();??}??}??//公共的增刪改方法public?int?allUpdateAndAddAndDel(List<Object>?list,String?sql){try?{conn=getConnection();ps=conn.prepareStatement(sql);if(list.size()>0){for?(int?i?=?0;?i?<?list.size();?i++)?{ps.setObject((i+1),?list.get(i));}}return?ps.executeUpdate();}?catch?(Exception?e)?{e.printStackTrace();return?-1;}finally{closeAll();}}//查詢公共方法public?ResultSet?select(String?sql,List<Object>?list)?{try?{conn=getConnection();ps=conn.prepareStatement(sql);if?(list.size()>0)?{for?(int?i?=?0;?i?<?list.size();?i++)?{ps.setObject((i+1),?list.get(i));}}rs=ps.executeQuery(); return?rs; }?catch?(Exception?e)?{e.printStackTrace();return?null; }} }

利用Jsp/Servlet實(shí)現(xiàn)：

?以實(shí)體類User為例，需要UserInfo.java:

//UserInfo.java import?java.util.Date;?? public?class?UserInfo?{??private?int?id;??private?String?username;??private?String?password;??private?String?truename;??private?String?sex;??private?Date?birthday;??private?String?home;??private?String?colleage;??private?String?comingYear;??public?int?getId()?{??return?id;??}??public?void?setId(int?id)?{??this.id?=?id;??}??public?String?getUsername()?{??return?username;??}??public?void?setUsername(String?username)?{??this.username?=?username;??}??public?String?getPassword()?{??return?password;??}??public?void?setPassword(String?password)?{??this.password?=?password;??}??public?String?getTruename()?{??return?truename;??}??public?void?setTruename(String?truename)?{??this.truename?=?truename;??}??public?String?getSex()?{??return?sex;??}??public?void?setSex(String?sex)?{??this.sex?=?sex;??}??public?Date?getBirthday()?{??return?birthday;??}??public?void?setBirthday(Date?birthday)?{??this.birthday?=?birthday;??}??public?String?getHome()?{??return?home;??}??public?void?setHome(String?home)?{??this.home?=?home;??}??public?String?getColleage()?{??return?colleage;??}??public?void?setColleage(String?colleage)?{??this.colleage?=?colleage;??}??public?String?getCy()?{??return?comingYear;??}??public?void?setCy(String?cy)?{??this.?comingYear=?cy;??}?? }

在dao層實(shí)現(xiàn)：

import?java.sql.Connection;?? import?java.sql.PreparedStatement;?? import?java.sql.ResultSet;?? import?java.sql.SQLException;?? import?java.util.ArrayList;?? import?java.util.List;?? import?entity.UserInfo;?? import?entity.BaseDao;??? public?class?UserInfoDao?{??public?List<UserInfo>?getUserList(UserInfo?userInfo,?int?pageNo,??int?hangCount?)?throws?Exception?{??PreparedStatement?pstmt?=?null;??ResultSet?rs?=?null;??List<UserInfo>?userList?=?null;??try?{??String?sql?=?"select?*?from(select?rownum?num,u.*?from(select?*?from?user_info?where?sex?=???and?home?like?'"??+?userInfo.getHome()??+?"%"??+?"'?and?colleage?like?'"??+?userInfo.getColleage()??+?"%"??+?"'?and?comingyear?like?'"??+?userInfo.getCy()??+?"%"??+?"'?order?by?id)?u?where?rownum<=?)?where?num>=?";??userList?=?new?ArrayList<UserInfo>();??Connection?conn?=?BaseDao.getConnection();??pstmt?=?conn.prepareStatement(sql);??pstmt.setString(1,?userInfo.getSex());??pstmt.setInt(2,?pageNo?*?hangCount);??pstmt.setInt(3,?(pageNo?-?1)?*?hangCount?+?1);??rs?=?pstmt.executeQuery();??while?(rs.next())?{??UserInfo?user?=?new?UserInfo();??user.setId(rs.getInt("id"));??user.setTruename(rs.getString("truename"));??user.setSex(rs.getString("sex"));??user.setHome(rs.getString("home"));??userList.add(user);??}??}?catch?(SQLException?e)?{??e.printStackTrace();??throw?new?Exception(e);??}?finally?{??BaseDao.closeResultSet(rs);??BaseDao.closePreparedStatement(pstmt);??}??return?userList;??}??public?int?getTotalNum(UserInfo?userInfo)?throws?Exception?{??PreparedStatement?pstmt?=?null;??ResultSet?rs?=?null;??int?count?=?0;??try?{??String?sql?=?"select?count(*)?from?user_info?where?sex=??and?home?like?'"??+?userInfo.getHome()??+?"%"??+?"'?and?colleage?like?'"??+?userInfo.getColleage()??+?"%"??+?"'?and?comingyear?like?'"??+?userInfo.getCy()+?"%"?+?"'";??Connection?conn?=?BaseDao.getConnection();??pstmt?=?conn.prepareStatement(sql);??pstmt.setString(1,?userInfo.getSex());??rs?=?pstmt.executeQuery();??if?(rs.next())?{??count?=?rs.getInt(1);??}??}?catch?(SQLException?e)?{??e.printStackTrace();??throw?new?Exception(e);??}?finally?{??BaseDao.closeResultSet(rs);??BaseDao.closePreparedStatement(pstmt);??}??return?count;??}?? }

在service層：

import?java.sql.Connection;?? import?util.BaseDao;?? import?util.Page;?? public?class?UserInfoManage?{??private?UserInfoDao?userInfoDao?=?null;??public?UserInfoManage?()?{??userInfoDao?=?new?UserInfoDao();??}??public?Page?userBasicSearch(UserInfo?u,?int?pageNo,??int?hangCount)?throws?Exception?{??Connection?connection?=?null;??Page?pagination?=?new?Page();??try?{??connection?=?BaseDao.getConnection();??DBUtility.setAutoCommit(connection,?false);??pagination.setList(userInfoDao.getUserList(u,?pageNo,?hangCount));??pagination.setPageNo(pageNo);??pagination.setHangCount(hangCount);??pagination.setSumCount(userInfoDao.getTotalNum(u));??BaseDao.commit(connection);??}?catch?(Exception?e)?{??DBUtility.rollBack(connection);??e.printStackTrace();??throw?new?Exception();??}?finally?{??BaseDao.closeConnection();??}??return?pagination;??}?? }

在Servlet:

import?java.io.*;?? import?java.util.*;??? import?javax.servlet.ServletConfig;?? import?javax.servlet.ServletException;?? import?javax.servlet.http.HttpServlet;?? import?javax.servlet.http.HttpServletRequest;?? import?javax.servlet.http.HttpServletResponse;??import?entity.UserInfo;?? import?service.UserInfoManage;?? import?util.Page;??public?class?UserBasicSearchServlet?extends?HttpServlet?{??private?static?final?long?serialVersionUID?=?1L;??private?int?hangCount?=?0;??@Override??public?void?init(ServletConfig?config)?throws?ServletException?{??hangCount?=?Integer.parseInt(config.getInitParameter("hangCount"));??}??@Override??protected?void?doGet(HttpServletRequest?req,?HttpServletResponse?resp)??throws?ServletException,?IOException?{??doPost(req,?resp);??}??@Override??protected?void?doPost(HttpServletRequest?req,?HttpServletResponse?resp)??throws?ServletException,?IOException?{??//?1.取得頁面參數(shù)并構(gòu)造參數(shù)對(duì)象??int?pageNo?=?Integer.parseInt(req.getParameter("pageNo"));??String?sex?=?req.getParameter("gender");??String?home?=?req.getParameter("newlocation");??String?colleage?=?req.getParameter("colleage");??String?comingyear?=?req.getParameter("ComingYear");??UserInfo?u?=?new?UserInfo();??u.setSex(sex);??u.setHome(home);??u.setColleage(colleage);??u.setCy(comingyear);??//?2.調(diào)用業(yè)務(wù)邏輯取得結(jié)果集??UserInfoManage?userInfoManage?=?new?UserInfoManage();??PageModel<UserInfo>?pagination?=?userInfoManage.userBasicSearch(u,??pageNo,?pageSize);??List<UserInfo>?userList?=?pagination.getList();??//?3.封裝返回結(jié)果??StringBuffer?resultXML?=?new?StringBuffer();??try?{??resultXML.append("<?xml?version='1.0'?encoding='gb18030'?>/n");??resultXML.append("<root>/n");??for?(Iterator<UserInfo>?iterator?=?userList.iterator();?iterator??.hasNext();)?{??UserInfo?userInfo?=?iterator.next();??resultXML.append("<data>/n");??resultXML.append("/t<id>"?+?userInfo.getId()?+?"</id>/n");??resultXML.append("/t<truename>"?+?userInfo.getTruename()??+?"</?truename?>/n");??resultXML.append("/t<sex>"?+?userInfo.getSex()?+?"</sex>/n");??resultXML.append("/t<home>"?+?userInfo.getHome()?+?"</home>/n");??resultXML.append("</data>/n");??}??resultXML.append("<pagination>/n");??resultXML.append("/t<total>"?+?pagination.getTotalPage()??+?"</total>/n");??resultXML.append("/t<start>"?+?pagination.getFirstPage()??+?"</start>/n");??resultXML.append("/t<end>"?+?pagination.getLastPage()?+?"</end>/n");??resultXML.append("/t<pageno>"?+?pagination.getPageNo()??+?"</pageno>/n");??resultXML.append("</pagination>/n");??resultXML.append("</root>/n");??}?catch?(Exception?e)?{??e.printStackTrace();??}??writeResponse(req,?resp,?resultXML.toString());??}??public?void?writeResponse(HttpServletRequest?request,??HttpServletResponse?response,?String?result)?throws?IOException?{??response.setContentType("text/xml");??response.setHeader("Cache-Control",?"no-cache");??response.setHeader("Content-Type",?"text/xml;?charset=gb18030");??PrintWriter?pw?=?response.getWriter();??pw.write(result);??pw.close();??}?? }

利用SSH實(shí)現(xiàn)：

在dao層編寫getSumCount()和List<Student> getStuByPage(Integer pageNo, Integer pageCount)2個(gè)方法：

有2種方法：第一種：使用普通的分頁方法//實(shí)現(xiàn)獲取總行數(shù)的方法import?org.hibernate.HibernateException;import?org.hibernate.Session;import?org.hibernate.Query;private?BaseUtil?baseUtil;//需要生成setXX()和getXX()方法public?Integer?getSumCount()?{//獲取sessionSession?session?=?baseUtil.getHibernateTemplate().getSessionFactory().openSession();//執(zhí)行查詢，調(diào)用查詢結(jié)果唯一的uniqueResult()方法;Object?object?=session.createQuery("select?count(別名.id)?from?類名?別名?").uniqueResult();//根據(jù)數(shù)據(jù)類型確定返回值，類型不對(duì)時(shí)需要強(qiáng)制轉(zhuǎn)換return?Integer.valueOf(object.toString());}//實(shí)現(xiàn)分頁的方法public?List<Entity>?getEntityByPage(Integer?pageNo,?Integer?pageCount)?{Session?session?=?baseUtil.getHibernateTemplate().getSessionFactory().openSession();Query?query?=?session.createQuery("from?類名?別名?");query.setMaxResults(pageCount);return?query.setFirstResult((pageNo-1)*pageCount).list();}第二種：使用Spring框架提供的方法import?org.hibernate.HibernateException;import?org.springframework.orm.hibernate3.HibernateCallback;import?org.hibernate.Query;//實(shí)現(xiàn)獲取總行數(shù)的方法public?Integer?getSumCount()?{Object?obj?=?baseUtil.getHibernateTemplate().execute(new?HibernateCallback()?{public?Object?doInHibernate(Session?session){Query?query?=?session.createQuery("select?count(別名.id)?from?類名?別名?");Object?object?=?query.uniqueResult();return?object;}});return?Integer.valueOf(obj.toString());}//實(shí)現(xiàn)分頁的方法getEntityByPage(final?Integer?pageNo,?final?Integer?pageCount)：方法內(nèi)的變量必須是finalpublic?List<Entity>?getEntityByPage(final?Integer?pageNo,?final?Integer?pageCount)?{List<Entity>?entitys?=?baseUtil.getHibernateTemplate().executeFind(new?HibernateCallback()?{public?Object?doInHibernate(Session?session){Query?query?=?session.createQuery("from?類名?別名");query.setMaxResults(pageCount);query.setFirstResult((pageNo-1)*pageCount);return?query.list();}});return?entitys?;}

? 在service層中：

????//EntityService.javaprivate?Page?page;//需要生成setXX()和getXX()方法private?Integer?pageNo=1；private?Integer?pageCount=1；public?Page?getEntityByPage(Integer?pageNo,?Integer?pageCount)?{if(page==null){page=new?Page();}page.setHangCount(pageCount);page.setSumCount(stuDao.getSumCount());page.setPageNo(pageNo);page.setEntitys(stuDao.getEntityByPage(page.getPageNo(),?page.getHangCount()));return?page;}

在action層中：

//EntityAction.java import?service.EntityService; import?util.Page; import?com.opensymphony.xwork2.ActionSupport; public?class?EntityAction?extends?ActionSupport?{private?EntityService?EntityService;//需要生成setXX()方法private?Page?page;//當(dāng)前頁，需要生成setXX()和getXX()方法private?Integer?pageNo=1;//當(dāng)前頁數(shù)，需要生成setXX()和getXX()方法private?Integer?pageCount=2;//每頁顯示行數(shù)，需要生成setXX()和getXX()方法@SuppressWarnings("unchecked")@Overridepublic?String?execute()?throws?Exception?{page=entityService.getEntityByPage(pageNo,?pageCount);return?SUCCESS;}

最后在jsp頁面：

<div?class=pager> <ul><li?class=current><a?href="form表單action名?pageNo=1">首頁</a></li><li><a?href="form表單action名?pageNo=${page.pageNo-1}">上一頁</a></li><li><a?href="form表單action名?pageNo=${page.pageNo+1}">下一頁</a></li><li><a?href="form表單action名?pageNo=${page.sumPage}">末頁</a></li> </ul> </DIV>

綜上所述，分頁功能可以基本實(shí)現(xiàn)。

文責(zé)聲明：本人借鑒得有別的作者的代碼，本人初探JavaWeb，技術(shù)有限，還望各位多多指正批評(píng)。如果文中有涉及之外的事情，還望見諒！

轉(zhuǎn)載于:https://blog.51cto.com/marklin1992/1759413

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