jsp+oracle兑现简单的分页

oracle脚本：drop table t_student cascade constraints;

/*==============================================================*/
/* Table: t_student                                           */
/*==============================================================*/
create table t_student  (
   s_id              char(10)                        not null,
   s_name             varchar2(20)                    not null,
   s_age              char(2)                         not null,
   s_sex              char(2)                         not null,
   s_class            varchar2(20),
   constraint PK_T_STUDENT primary key (s_id)
);

insert into t_student values('0001','张三','20','男','08级二班') ;
insert into t_student values('0002','李四','21','女','08级二班') ;
insert into t_student values('0003','王五','20','男','08级二班') ;
insert into t_student values('0004','赵柳','20','女','08级一班') ;
insert into t_student values('0005','杨梅','21','男','08级二班') ;
insert into t_student values('0006','刘海','23','女','08级一班') ;
insert into t_student values('0007','孙江','20','女','08级一班') ;
insert into t_student values('0008','苏灿','22','男','08级二班') ;
insert into t_student values('0009','王霞','23','女','08级一班') ;
insert into t_student values('0010','王猛','22','男','08级二班') ;
insert into t_student values('0011','张相','22','女','08级一班') ;
insert into t_student values('0012','香橙','20','女','08级一班') ;
insert into t_student values('0013','李心','21','女','08级二班') ;
insert into t_student values('0014','张强','20','男','08级一班') ;
insert into t_student values('0015','赵琳','21','女','08级一班') ;
insert into t_student values('0016','刘达','21','男','08级二班') ;
insert into t_student values('0017','苏惠','20','女','08级二班') ;
insert into t_student values('0018','贾瑞','20','女','08级一班') ;
insert into t_student values('0019','谷瑞坤','22','男','08级二班') ;
insert into t_student values('0020','祥还','21','男','08级一班') ;
commit;

??采用单利模式创建DbUtil类获得Connection对象：package com.stmcc.test.util;

import java.sql.*;

public class DbUtil {

	private static final String driver = "oracle.jdbc.driver.OracleDriver" ;
	private static final String url = "jdbc:oracle:thin:@10.10.10.2:1521:orcl" ;
	private static final String username = "test" ;
	private static final String password = "test" ;
	public static Connection getConnection(){
		Connection conn = null ;
		try{
			Class.forName(driver) ;
			conn = DriverManager.getConnection(url, username, password) ;
		}catch(Exception e){
			e.printStackTrace() ;
		}
		return conn ;
	}

	public static void close(Connection conn) {
		if (conn != null) {
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
	
	public static void close(PreparedStatement pstmt) {
		if (pstmt != null) {
			try {
				pstmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
	
	public static void close(ResultSet rs ) {
		if (rs != null) {
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
	public static void main(String[] args) {
		System.out.println(DbUtil.getConnection());
	}
}

?创建学生实体类：package com.stmcc.test;

public class Student {

	private String s_id ;
	private String s_name ;
	private String s_age ;
	private String s_sex ;
	private String s_class ;
	public String getS_id() {
		return s_id;
	}
	public void setS_id(String s_id) {
		this.s_id = s_id;
	}
	public String getS_name() {
		return s_name;
	}
	public void setS_name(String s_name) {
		this.s_name = s_name;
	}
	public String getS_age() {
		return s_age;
	}
	public void setS_age(String s_age) {
		this.s_age = s_age;
	}
	public String getS_sex() {
		return s_sex;
	}
	public void setS_sex(String s_sex) {
		this.s_sex = s_sex;
	}
	public String getS_class() {
		return s_class;
	}
	public void setS_class(String s_class) {
		this.s_class = s_class;
	}
}

??创建学生管理类：package com.stmcc.test.util;

import com.stmcc.test.*;
import java.sql.* ;
import java.util.*; 
public class StuManager {

	private static StuManager instance = new StuManager() ;
	
	private StuManager(){} ;
	
	public static StuManager getInstance(){
		return instance ;
	}
//  oracle实现分页的查询语句
//	select s_id, s_name, s_age, s_sex, s_class
//	from
//	(
//	  select rownum rn, s_id, s_name, s_age, s_sex, s_class
//	  from
//	    (select s_id, s_name, s_age, s_sex, s_class 
//	     from t_student order by s_id
//	    )where rownum <= 10
//	)where rn > 5 ;
	public PageModel findStudentList(int pageNo, int pageSize){
		PageModel pageModel = null ;
		StringBuffer sql = new StringBuffer() ;
		sql.append("select s_id, s_name, s_age, s_sex, s_class ")
			.append("from")
			.append("(")
			.append("select rownum rn, s_id, s_name, s_age, s_sex, s_class ")
			.append("from")
			.append("(")
			.append("select s_id, s_name, s_age, s_sex, s_class ")
			.append("from t_student order by s_id")
			.append(")")
			.append("where rownum <= ?")
			.append(")")
			.append("where rn > ? ");
		Connection conn = null ;
		PreparedStatement pstmt = null ;
		ResultSet rs = null ;
		try{
			conn = DbUtil.getConnection() ;
			pstmt = conn.prepareStatement(sql.toString()) ;
			pstmt.setInt(1, pageNo*pageSize) ;
			pstmt.setInt(2, (pageNo - 1)*pageSize) ;
			rs = pstmt.executeQuery() ;
			List<Student> stuList = new ArrayList<Student>() ;
			while (rs.next()){
				Student stu = new Student() ;
				stu.setS_id(rs.getString("s_id")) ;
				stu.setS_name(rs.getString("s_name")) ;
				stu.setS_age(rs.getString("s_age")) ;
				stu.setS_sex(rs.getString("s_sex")) ;
				stu.setS_class(rs.getString("s_class")) ;
				stuList.add(stu) ;
			}
			pageModel = new PageModel() ;
			pageModel.setList(stuList) ;
			pageModel.setTotalRecords(getTotalRecords(conn)) ;
			pageModel.setPageSize(pageSize);
			pageModel.setPageNo(pageNo);
		}catch(Exception e){
			e.printStackTrace() ;
		}finally{
			DbUtil.close(rs) ;
			DbUtil.close(pstmt) ;
			DbUtil.close(conn) ;
		}
		return pageModel ;
	}
	/**
	 * 取得总记录数
	 * @param conn
	 * @return
	 */
	private int getTotalRecords(Connection conn) 
	throws SQLException {
		String sql = "select count(*) from t_student";
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		int count = 0;
		try {
			pstmt = conn.prepareStatement(sql);
			rs = pstmt.executeQuery();
			rs.next();
			count = rs.getInt(1);
		}finally {
			DbUtil.close(rs);
			DbUtil.close(pstmt);
		}
		return count;
	}
}

?创建分页模型类实现业务逻辑：package com.stmcc.test.util;

import java.util.* ;
public class PageModel {

	//结果集
	private List list ;
	
	//查询总记录数
	private int totalRecords ;
	
	//每页多少条数据
	private int pageSize ;
	
	//第几页
	private int pageNo ;
	
	/**
	 * 总页数
	 * @return
	 */
	public int getTotalPages(){
		return (totalRecords + pageSize -1) / pageSize ;
	}
	
	/**
	 * 取得首页
	 * @return
	 */
	public int getTopPageNo(){
		return 1 ;
	}
	
	/**
	 * 上一页
	 * @return
	 */
	public int getPreviousPageNo(){
		if(pageNo <= 1){
			return 1 ;
		}
		return pageNo - 1 ;
	}
	
	/**
	 * 下一页
	 * @return
	 */
	public int getNextPageNo(){
		if(pageNo >= getBottomPageNo()){
			return getBottomPageNo() ;
		}
		return pageNo + 1 ;
	}
	
	/**
	 * 取得尾页
	 * @return
	 */
	public int getBottomPageNo(){
		return getTotalPages() ;
	}

	public List getList() {
		return list;
	}

	public void setList(List list) {
		this.list = list;
	}

	public int getTotalRecords() {
		return totalRecords;
	}

	public void setTotalRecords(int totalRecords) {
		this.totalRecords = totalRecords;
	}

	public int getPageSize() {
		return pageSize;
	}

	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}

	public int getPageNo() {
		return pageNo;
	}

	public void setPageNo(int pageNo) {
		this.pageNo = pageNo;
	}
}

?jsp页面：<%@ page contentType="text/html" pageEncoding="GBK"%>

<%@ page import="com.stmcc.test.util.*"%>
<%@ page import="com.stmcc.test.*"%>
<%@ page import="java.sql.*"%>
<%@ page import="java.util.*"%>
<html>
<head><title>分页展示</title></head>
<%
	int pageNo = 1 ;
	int pageSize = 5 ;
	String pageNoString = request.getParameter("pageNo") ;
	if(pageNoString != null){
		pageNo = Integer.parseInt(pageNoString) ;
	}
	PageModel pageModel = StuManager.getInstance().findStudentList(pageNo,pageSize) ;
%>
<script type="text/javaScript">
	function topPage() {
		window.self.location = "student.jsp?pageNo=<%=pageModel.getTopPageNo()%>";
	}
	
	function previousPage() {
		window.self.location = "student.jsp?pageNo=<%=pageModel.getPreviousPageNo()%>";
	}	
	
	function nextPage() {
		window.self.location = "student.jsp?pageNo=<%=pageModel.getNextPageNo()%>";
	}
	
	function bottomPage() {
		window.self.location = "student.jsp?pageNo=<%=pageModel.getBottomPageNo()%>";
	}
</script>
<body>
<center>
  <table border="1">
  <tr>
  	<td>学生编号</td>
  	<td>学生姓名</td>
  	<td>学生年龄</td>
  	<td>学生性别</td>
  	<td>学生班级</td>
  </tr>
  <%
  	List stuList = pageModel.getList() ;
  	for(Iterator<Student> iter = stuList.iterator(); iter.hasNext();){
  		Student stu = iter.next() ;
  %>
  <tr>
  	<td><%=stu.getS_id() %></td>
  	<td><%=stu.getS_name() %></td>
  	<td><%=stu.getS_age() %></td>
  	<td><%=stu.getS_sex() %></td>
  	<td><%=stu.getS_class() %></td>
  </tr>
  <%
  	}
  %>
  <tr><td colspan="5">
      共&nbsp;<%=pageModel.getTotalPages() %>&nbsp;页&nbsp;&nbsp;&nbsp;&nbsp;
      当前第&nbsp;<%=pageModel.getPageNo() %>页&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
  <input type="button" value="首页" onClick="topPage()">
  <input type="button" value="上一页" onClick="previousPage()">
  <input type="button" value="下一页" onClick="nextPage()">
  <input type="button" value="尾页" onClick="bottomPage()">
  </td></tr>
  </table>
</center>
</body>
</html>