小编给大家分享一下Oracle中Java分页功能有哪些，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！

就如平时我们很在分页中看到的，分页的时候返回的不仅包括查询的结果集(List)，而且还包括总的页数(pageNum)、当前第几页(pageNo)等等信息，所以我们封装一个查询结果PageModel类，代码如下：

packagecom.bjpowernode.test;importjava.util.List;publicclassPageModel<E>{privateList<E>list;privateintpageNo;privateintpageSize;privateinttotalNum;privateinttotalPage;publicList<E>getList(){returnlist;}publicvoidsetList(List<E>list){this.list=list;}publicintgetPageNo(){returnpageNo;}publicvoidsetPageNo(intpageNo){this.pageNo=pageNo;}publicintgetPageSize(){returnpageSize;}publicvoidsetPageSize(intpageSize){this.pageSize=pageSize;}publicintgetTotalNum(){returntotalNum;}publicvoidsetTotalNum(inttotalNum){this.totalNum=totalNum;setTotalPage((getTotalNum()%pageSize)==0?(getTotalNum()/pageSize):(getTotalNum()/pageSize+1));}publicintgetTotalPage(){returntotalPage;}publicvoidsetTotalPage(inttotalPage){this.totalPage=totalPage;}//获取第一页publicintgetFirstPage(){return1;}//获取最后页publicintgetLastPage(){returntotalPage;}//获取前页publicintgetPrePage(){if(pageNo>1)returnpageNo-1;return1;}//获取后页publicintgetBackPage(){if(pageNo<totalPage)returnpageNo+1;returntotalPage;}//判断'首页'及‘前页'是否可用publicStringisPreable(){if(pageNo==1)return"disabled";return"";}//判断'尾页'及‘下页'是否可用publicStringisBackable(){if(pageNo==totalPage)return"disabled";return"";}}

其中使用泛型是为了能使的该分页类能进行重用，比如在查询用户时可以封装User对象、在查询财务中的流向单时可以封装流向单FlowCard类。

我们以查询用户为例，用户选择查询条件，首先调用Servlet获取查询参数，然后请求业务逻辑层取得分页封装结果类。业务逻辑调用Dao层取得结果集、取得中记录数封装成分页类。最后Servlet将结果设置到jsp页面显示。

首先来讲解Servlet，代码如下：

packagecom.bjpowernode.test;importjava.io.*;importjava.util.*;importjavax.servlet.ServletConfig;importjavax.servlet.ServletException;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importkane.UserInfo;importkane.UserInfoManage;importkane.PageModel;publicclassUserBasicSearchServletextendsHttpServlet{privatestaticfinallongserialVersionUID=1L;privateintpageSize=0;@Overridepublicvoidinit(ServletConfigconfig)throwsServletException{pageSize=Integer.parseInt(config.getInitParameter("pageSize"));}@OverrideprotectedvoiddoGet(HttpServletRequestreq,HttpServletResponseresp)throwsServletException,IOException{doPost(req,resp);}@OverrideprotectedvoiddoPost(HttpServletRequestreq,HttpServletResponseresp)throwsServletException,IOException{//1.取得页面参数并构造参数对象intpageNo=Integer.parseInt(req.getParameter("pageNo"));Stringsex=req.getParameter("gender");Stringhome=req.getParameter("newlocation");Stringcolleage=req.getParameter("colleage");Stringcomingyear=req.getParameter("ComingYear");UserInfou=newUserInfo();u.setSex(sex);u.setHome(home);u.setColleage(colleage);u.setCy(comingyear);//2.调用业务逻辑取得结果集UserInfoManageuserInfoManage=newUserInfoManage();PageModel<UserInfo>pagination=userInfoManage.userBasicSearch(u,pageNo,pageSize);List<UserInfo>userList=pagination.getList();//3.封装返回结果StringBufferresultXML=newStringBuffer();try{resultXML.append("<?xmlversion='1.0'encoding='gb18030'?>/n");resultXML.append("<root>/n");for(Iterator<UserInfo>iterator=userList.iterator();iterator.hasNext();){UserInfouserInfo=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(Exceptione){e.printStackTrace();}writeResponse(req,resp,resultXML.toString());}publicvoidwriteResponse(HttpServletRequestrequest,HttpServletResponseresponse,Stringresult)throwsIOException{response.setContentType("text/xml");response.setHeader("Cache-Control","no-cache");response.setHeader("Content-Type","text/xml;charset=gb18030");PrintWriterpw=response.getWriter();pw.write(result);pw.close();}}

其中User对象代码如下：

packagecom.bjpowernode.test;importjava.util.Date;publicclassUserInfo{privateintid;privateStringusername;privateStringpassword;privateStringtruename;privateStringsex;privateDatebirthday;privateStringhome;privateStringcolleage;privateStringcomingYear;publicintgetId(){returnid;}publicvoidsetId(intid){this.id=id;}publicStringgetUsername(){returnusername;}publicvoidsetUsername(Stringusername){this.username=username;}publicStringgetPassword(){returnpassword;}publicvoidsetPassword(Stringpassword){this.password=password;}publicStringgetTruename(){returntruename;}publicvoidsetTruename(Stringtruename){this.truename=truename;}publicStringgetSex(){returnsex;}publicvoidsetSex(Stringsex){this.sex=sex;}publicDategetBirthday(){returnbirthday;}publicvoidsetBirthday(Datebirthday){this.birthday=birthday;}publicStringgetHome(){returnhome;}publicvoidsetHome(Stringhome){this.home=home;}publicStringgetColleage(){returncolleage;}publicvoidsetColleage(Stringcolleage){this.colleage=colleage;}publicStringgetCy(){returncomingYear;}publicvoidsetCy(Stringcy){this.comingYear=cy;}}

接着是业务逻辑层代码，代码如下：

packagecom.bjpowernode.test;importjava.sql.Connection;importkane.DBUtility;importkane.PageModel;publicclassUserInfoManage{privateUserInfoDaouserInfoDao=null;publicUserInfoManage(){userInfoDao=newUserInfoDao();}publicPageModel<UserInfo>userBasicSearch(UserInfou,intpageNo,intpageSize)throwsException{Connectionconnection=null;PageModel<UserInfo>pagination=newPageModel<UserInfo>();try{connection=DBUtility.getConnection();DBUtility.setAutoCommit(connection,false);pagination.setList(userInfoDao.getUserList(u,pageNo,pageSize));pagination.setPageNo(pageNo);pagination.setPageSize(pageSize);pagination.setTotalNum(userInfoDao.getTotalNum(u));DBUtility.commit(connection);}catch(Exceptione){DBUtility.rollBack(connection);e.printStackTrace();thrownewException();}finally{DBUtility.closeConnection();}returnpagination;}}

其中DBUtility为数据库的连接封装类。

最后是Dao层代码实现，代码如下：

packagecom.bjpowernode.test;importjava.sql.Connection;importjava.sql.PreparedStatement;importjava.sql.ResultSet;importjava.sql.SQLException;importjava.util.ArrayList;importjava.util.List;importkane.UserInfo;importkane.DBUtility;publicclassUserInfoDao{publicList<UserInfo>getUserList(UserInfouserInfo,intpageNo,intpageSize)throwsException{PreparedStatementpstmt=null;ResultSetrs=null;List<UserInfo>userList=null;try{Stringsql="select*from(selectrownumnum,u.*from(select*fromuser_infowheresex=?andhomelike'"+userInfo.getHome()+"%"+"'andcolleagelike'"+userInfo.getColleage()+"%"+"'andcomingyearlike'"+userInfo.getCy()+"%"+"'orderbyid)uwhererownum<=?)wherenum>=?";userList=newArrayList<UserInfo>();Connectionconn=DBUtility.getConnection();pstmt=conn.prepareStatement(sql);pstmt.setString(1,userInfo.getSex());pstmt.setInt(2,pageNo*pageSize);pstmt.setInt(3,(pageNo-1)*pageSize+1);rs=pstmt.executeQuery();while(rs.next()){UserInfouser=newUserInfo();user.setId(rs.getInt("id"));user.setTruename(rs.getString("truename"));user.setSex(rs.getString("sex"));user.setHome(rs.getString("home"));userList.add(user);}}catch(SQLExceptione){e.printStackTrace();thrownewException(e);}finally{DBUtility.closeResultSet(rs);DBUtility.closePreparedStatement(pstmt);}returnuserList;}publicintgetTotalNum(UserInfouserInfo)throwsException{PreparedStatementpstmt=null;ResultSetrs=null;intcount=0;try{Stringsql="selectcount(*)fromuser_infowheresex=?andhomelike'"+userInfo.getHome()+"%"+"'andcolleagelike'"+userInfo.getColleage()+"%"+"'andcomingyearlike'"+userInfo.getCy()+"%"+"'";Connectionconn=DBUtility.getConnection();pstmt=conn.prepareStatement(sql);pstmt.setString(1,userInfo.getSex());rs=pstmt.executeQuery();if(rs.next()){count=rs.getInt(1);}}catch(SQLExceptione){e.printStackTrace();thrownewException(e);}finally{DBUtility.closeResultSet(rs);DBUtility.closePreparedStatement(pstmt);}returncount;}}

最后就是servlet将得到的结果返回给jsp页面显示出来。

注：其中DBUtility代码是封装数据库连接操作的代码，如下：

1.package com.bjpowernode.test;

importjava.sql.Connection;importjava.sql.DriverManager;importjava.sql.PreparedStatement;importjava.sql.ResultSet;importjava.sql.SQLException;publicclassDBUtility{privatestaticThreadLocal<Connection>threadLocal=newThreadLocal<Connection>();publicstaticConnectiongetConnection(){Connectionconn=null;conn=threadLocal.get();if(conn==null){try{Class.forName("oracle.jdbc.driver.OracleDriver");conn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:oracle","admin","admin");threadLocal.set(conn);}catch(ClassNotFoundExceptione){e.printStackTrace();}catch(SQLExceptione){e.printStackTrace();}}returnconn;}//封装设置Connection自动提交publicstaticvoidsetAutoCommit(Connectionconn,Booleanflag){try{conn.setAutoCommit(flag);}catch(SQLExceptione){e.printStackTrace();}}//设置事务提交publicstaticvoidcommit(Connectionconn){try{conn.commit();}catch(SQLExceptione){e.printStackTrace();}}//封装设置Connection回滚publicstaticvoidrollBack(Connectionconn){try{conn.rollback();}catch(SQLExceptione){e.printStackTrace();}}//封装关闭Connection、PreparedStatement、ResultSet的函数publicstaticvoidcloseConnection(){Connectionconn=threadLocal.get();try{if(conn!=null){conn.close();conn=null;threadLocal.remove();}}catch(SQLExceptione){e.printStackTrace();}}publicstaticvoidclosePreparedStatement(PreparedStatementpstmt){try{if(pstmt!=null){pstmt.close();pstmt=null;}}catch(SQLExceptione){e.printStackTrace();}}publicstaticvoidcloseResultSet(ResultSetrs){try{if(rs!=null){rs.close();rs=null;}}catch(SQLExceptione){e.printStackTrace();}}}

使用ThreadLocal是为了保证事务的一致，使得同一个线程的所有数据库操作使用同一个Connection。

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