Java-分页实例

1、PageModel.java

package com.javaweb;

import java.util.List;

public class PageModel<E> {

 private List<E> list; //结果集
 private int totalRecords; //查询记录数
 private int pageSize; //每页多少记录
 private int pageNo; //当前页

 //总页数
 public int getTotalPages(){
  return (totalRecords + pageSize - 1) / pageSize;
 }

 //取得首页
 public int getTopPageNo(){
  return 1;
 }

 //取得上一页
 public int getPreviousPageNo(){
  if(pageNo<=1)
   return 1;
  return pageNo-1;
 }

 // 取得下一页
 public int getNextPageNo(){
  if(pageNo >= getBottomPageNo())
   return getBottomPageNo();
  return pageNo+1;
 }

 //取得尾页
 public int getBottomPageNo(){
  return getTotalPages();
 }

 public List<E> getList() {
  return list;
 }

 public void setList(List<E> 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;
 }

}

2、Book.java

package com.javaweb.book;
public class Book {
 private String id;
 private String name;
 private String title;
 private float price;
 private int year;
 private String description;
 private int saleAmount;

 public String getId() {
  return id;
 }
 public void setId(String id) {
  this.id = id;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public String getTitle() {
  return title;
 }
 public void setTitle(String title) {
  this.title = title;
 }
 public float getPrice() {
  return price;
 }
 public void setPrice(float price) {
  this.price = price;
 }
 public int getYear() {
  return year;
 }
 public void setYear(int year) {
  this.year = year;
 }
 public String getDescription() {
  return description;
 }
 public void setDescription(String description) {
  this.description = description;
 }
 public int getSaleAmount() {
  return saleAmount;
 }
 public void setSaleAmount(int saleAmount) {
  this.saleAmount = saleAmount;
 }
}

3、BookDb.java

package com.javaweb.book;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.*;
import com.javaweb.*;
public class BookDb {

 // 返回所有book
 public List<Book> getAllBooks(){
  String sql = "select * from books order by id";
  Connection conn = null;
  PreparedStatement pstmt = null;
  ResultSet rs = null;
  List<Book> bookList = null;
  try{
   conn = DbUtil.getConnection();
   pstmt = conn.prepareStatement(sql);
   rs = pstmt.executeQuery();
    bookList = new ArrayList<Book>();
   while(rs.next()){
    Book book = new Book();
    book.setId(rs.getString("id"));
    book.setName(rs.getString("name"));
    book.setTitle(rs.getString("title"));
    book.setPrice(rs.getFloat("price"));
    book.setYear(rs.getInt("yr"));
    book.setDescription(rs.getString("description"));
    book.setSaleAmount(rs.getInt("sale_amount"));
    bookList.add(book);
   }
  }catch(SQLException e){
   e.printStackTrace();
  }finally{
   DbUtil.close(rs);
   DbUtil.close(pstmt);
   DbUtil.close(conn);
  }
  return bookList;
 }

 //返回id查询book
 //@param id book的id
 public Book getBookById(String id){
  String sql = "select * from books where id=?";
  Connection conn = null;
  PreparedStatement pstmt = null;
  ResultSet rs = null;
  Book book = null;
  try{
   conn = DbUtil.getConnection();
   pstmt = conn.prepareStatement(sql);
   pstmt.setString(1, id);
   rs = pstmt.executeQuery();
   while(rs.next()){
    book = new Book();
    book.setId(rs.getString("id"));
    book.setName(rs.getString("name"));
    book.setTitle(rs.getString("title"));
    book.setPrice(rs.getFloat("price"));
    book.setYear(rs.getInt("yr"));
    book.setDescription(rs.getString("description"));
    book.setSaleAmount(rs.getInt("sale_amount"));
   }
  }catch(SQLException e){
   e.printStackTrace();
  }finally{
   DbUtil.close(rs);
   DbUtil.close(pstmt);
   DbUtil.close(conn);
  }
  return book;
 }

 //分页查询(上一页、下一页)
 //@param pageNo 第几页
 //@param pageSize 每页多少记录
 public PageModel<Book> findBookList(int pageNo,int pageSize){
  String sql = "select * from books order by id limit ?,?";
  Connection conn = null;
  PreparedStatement pstmt = null;
  ResultSet rs = null;
  PageModel<Book> pageModel = null;
  try{
   conn = DbUtil.getConnection();
   pstmt = conn.prepareStatement(sql);
   pstmt.setInt(1, (pageNo-1)*pageSize);
   pstmt.setInt(2, pageSize);
   rs = pstmt.executeQuery();
   List<Book> bookList = new ArrayList<Book>();
   while(rs.next()){
    Book book = new Book();
    book.setId(rs.getString("id"));
    book.setName(rs.getString("name"));
    book.setTitle(rs.getString("title"));
    book.setPrice(rs.getFloat("price"));
    book.setYear(rs.getInt("yr"));
    book.setDescription(rs.getString("description"));
    book.setSaleAmount(rs.getInt("sale_amount"));
    bookList.add(book);
   }
   pageModel = new PageModel<Book>();
   pageModel.setList(bookList);
   pageModel.setPageNo(pageNo);
   pageModel.setPageSize(pageSize);
   pageModel.setTotalRecords(getTotalRecords(conn));
  }catch(SQLException e){
   e.printStackTrace();
  }finally{
   DbUtil.close(rs);
   DbUtil.close(pstmt);
   DbUtil.close(conn);
  }
  return pageModel;
 } 

 //取得总记录数
 private int getTotalRecords(Connection conn)
 throws SQLException{
  String sql = "select count(*) from books";
  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;
 }
}

4、DbUtil.java

package com.javaweb.book;
import java.sql.*;

public class DbUtil {

 private final static String driver = "com.mysql.jdbc.Driver";
 private final static String url = "jdbc:mysql://localhost:3306/bookdb";
 private final static String user = "root";
 private final static String password = "123456";

 public static Connection getConnection(){
  try{
   Class.forName(driver);
   Connection conn = DriverManager.getConnection(url,user,password);
   return conn;
  }catch(ClassNotFoundException e){
   System.out.println("找不到数据库驱动");
   System.out.println(e.getMessage());
  }catch(SQLException e){
   System.out.println("数据库连接失败");
   System.out.println(e.getMessage());
  }
  return null;
 }

 public static void close(Connection conn){
  if(conn!=null){
   try{
    conn.close();
   }catch(SQLException e){
    System.out.println("关闭数据库连接出错");
    System.out.println(e.getMessage());
   }
  }
 }

 public static void close(ResultSet rs){
  if(rs!=null){
   try{
    rs.close();
   }catch(SQLException e){
    e.printStackTrace();
   }
  }
 }

 public static void close(PreparedStatement pstmt){
  if(pstmt!=null){
   try{
    pstmt.close();
   }catch(SQLException e){
    e.printStackTrace();
   }
  }
 }
}

5、bookstore.jsp

<%@ page contentType="text/html;charset=GBK" %>
<html>
<head><title>Bookstore</title>

</head>
<body>
<center>
<p><b><a href="http://blog.163.com/jesse_zy/blog/<%=request.getContextPath()%>/catalog.jsp">查看所有书目</a></b>
</center>

</body>
</html>

6、catalog.jsp

<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%@ page import="java.util.*" %>
<%@ page import="com.javaweb.*" %>
<%@ page import="com.javaweb.book.*" %>
<%
 int pageNo = 1;
 int pageSize = 4;
 String pageNoString = request.getParameter("pageNo");
 if(pageNoString != null){
  pageNo = Integer.parseInt(pageNoString);
 }
 PageModel<Book> pageModel = new BookDb().findBookList(pageNo,pageSize);
%>

<html>
  <head>
    <title>图书详细信息</title>
    <link rel="stylesheet" href="http://blog.163.com/jesse_zy/blog/style.css">
  </head>

  <script type="text/javascript">

    function topPage() {
  window.self.location = "catalog.jsp?pageNo=<%=pageModel.getTopPageNo()%>";
 }

 function previousPage() {
  window.self.location = "catalog.jsp?pageNo=<%=pageModel.getPreviousPageNo()%>";
 } 

 function nextPage() {
  window.self.location = "catalog.jsp?pageNo=<%=pageModel.getNextPageNo()%>";
 }

 function bottomPage() {
  window.self.location = "catalog.jsp?pageNo=<%=pageModel.getBottomPageNo()%>";
 }
  </script>

  <body>
  <div align="center">
    <form>
      <table width="900" height="30" border="0" cellspacing="0">
        <tr>
          <td>图书列表</td>
          <td align="right"><a href="http://blog.163.com/jesse_zy/blog/bookstore.jsp">返回主页</a></td>
        </tr>
      </table>
      <table  width="900" border="1" cellspacing="0" cellpadding="0">
        <tr>
          <th>ID</th>
          <th>作者</th>
          <th>书名</th>
          <th>价格</th>
          <th>出版年份</th>
          <th>描述</th>
          <th>销量</th>
        </tr>
        <%
         List<Book> bookList = pageModel.getList();
         for(Book book:bookList){
        %>
        <tr>
          <td><%= book.getId()%></td>
          <td><%= book.getName()%></td>
          <td><%= book.getTitle()%></td>
          <td><%= book.getPrice()%></td>
          <td><%= book.getYear()%></td>
          <td><%= book.getDescription()%></td>
          <td><%= book.getSaleAmount()%></td>
        </tr>
        <%
         }
        %>
      </table>
      <table width="900" height="35" border="0" cellspacing="0">
       <tr>
         <td>
          <div>
     共 <%=pageModel.getTotalPages() %> 页</font>    
    当前第 <font color="red"><%=pageModel.getPageNo() %></font> 页
   </div>
         </td>
         <td>
   <div align="right">
    <input type="button" value="首页" onClick="topPage()"
    <% if(pageNo<=1) {
    %>disabled="disabled"
    <% }%>>
    <input type="button" value="上一页" onClick="previousPage()"
    <% if(pageNo<=1) {
    %>disabled="disabled"
    <% }%>>
    <input type="button" value="下一页" onClick="nextPage()"
    <% if(pageNo>=pageModel.getBottomPageNo()) {
    %>disabled="disabled"
    <% }%>>
    <input type="button" value="尾页" onClick="bottomPage()"
    <% if(pageNo>=pageModel.getBottomPageNo()) {
    %>disabled="disabled"
    <% }%>> 
   </div>
    </td>
       <tr>
      </table>
    </form>
    </div>
  </body>
</html>

7、style.css

th{
 font-family : 宋体;
 font-size : 12pt;
}
td{
 font-family : 宋体;
 font-size : 11pt;
}

8、books.sql

drop database BookDB;
create database BookDB;
use BookDB;

create table BOOKS(
ID varchar(8) primary key,
NAME varchar(24),
TITLE varchar(96),
PRICE float,
YR int,
DESCRIPTION varchar(128),
SALE_AMOUNT int);

insert into BOOKS values('001','李建',
'Java面向对象编程',65,
2006, '让读者由浅入深掌握Java语言', 20000);

insert into BOOKS values('001','李建',
'Java面向对象编程',65,
2006, '让读者由浅入深掌握Java语言', 20000);

insert into BOOKS values('002', '李建',
 '精通Struts', 49,
 2004, '真的很棒', 80000);

insert into BOOKS values('003', '李建',
 'Tomcat与JavaWeb开发技术详解',
 45, 2004, '关于Tomcat与JavaWeb开发的技术书', 40000);

insert into BOOKS values('004', '李建',
 'Java网络编程精解',
55, 2007, '很值得一看', 20000);

insert into BOOKS values('005', '李建',
 '精通Hibernate',
 59, 2005, '权威的Hibernate技术资料', 50000);

insert into BOOKS values('006', '李建',

'Java2认证考试指南与试题解析',
 88, 2002, '权威的Java技术资料', 8000);