jsp+jdbc+javaBean+servlet实现分页显示功能

深藏阁楼爱情的钟 2022-05-23 04:59 208阅读 0赞

数据库中的数据表数据如下：

![20180602144151480][]

javaBean: 建立Page类用来存储从数据库查询到的数据信息和当前页面信息。

public class Page {
    	private int pagenum;//当前页面
    	private int pagesize;//页面大小
    	private List<Book> books;//页面数据
    	public int getPagenum() {
    		return pagenum;
    	}
    	public void setPagenum(int pagenum) {
    		this.pagenum = pagenum;
    	}
    	public int getPagesize() {
    		return pagesize;
    	}
    	public void setPagesize(int pagesize) {
    		this.pagesize = pagesize;
    	}
    	public List<Book> getBooks() {
    		return books;
    	}
    	public void setBooks(List<Book> books) {
    		this.books = books;
    	}
    }

Dao层（只给出了方法）：

public List<Book> getPageDates(int startindex, int endindex) {
    		// TODO Auto-generated method stub
    				List<Book> bookList=new ArrayList<Book>();
    				Connection con=null;
    				PreparedStatement ps=null;
    				ResultSet rs=null;
    				String sql="select * " + 
    						"from book " + 
    						"limit ?,? ";
    				con=DbUtils.getConnection();//连接数据库
    		    	try {
    		    		ps=con.prepareStatement(sql);
    		    		ps.setInt(1,startindex);
    		    		ps.setInt(2, endindex);
    		    		rs=ps.executeQuery();
    		    		while(rs.next()) {
    		    			Book b1=new Book();
    		    			b1.setBookid(rs.getInt(1));
    		    			b1.setBookname(rs.getString(2));
    		    			b1.setAuthor(rs.getString(3));
    		    			b1.setPublishing_house(rs.getString(4));
    		    			b1.setPrice(rs.getDouble(5));
    		    			b1.setInformation(rs.getString(6));
    		    			b1.setStock(rs.getInt(7));
    		    			bookList.add(b1);
    		    		}
    		    		return bookList;
    		    	}catch(Exception e) {
    		    		return null;
    		    	}
    	}

Service层（只给出了查找页面数据的方法）：

public Page getPageDates(int startindex,int endindex) {
        	Page page=new Page();
        	page.setBooks(bookDao.getPageDates(startindex, endindex));
        	return page;
        }

Servlet（doGet方法）:首先判断当前页面是那一页，若获取当前页面为空或者值等于0，则从数据表0索引位置开始查找；反之，当前页面的大小乘每页数据量为起始索引位置开始查找。

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		String pagenum=(String)request.getParameter("pagenum");//获取当前页面大小
    		int startindex=0;
    		int endindex=0;
    		Integer page_num;
    		if(pagenum==null) {//当前页面为空
    			page_num=0;
    			startindex=0;
    			endindex=5;
    		}else {//当前页面不为空
    			 page_num=Integer.parseInt(pagenum);
    			 if(page_num<=0) {
    				 page_num=0;
    					startindex=0;
    					endindex=5;
    			 }else {
    				 startindex=5*page_num;
    					endindex=5;
    			 }
    			
    		}
    		Page page=businessService.getPageDates(startindex, endindex);  //查找数据
    		page.setPagenum(page_num);
    		request.setAttribute("page", page);  //将页面信息作为参数传递给jsp页面
    		request.getRequestDispatcher("showBookByPage.jsp").forward(request, response);
    	}

jsp页面：

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%@ page import="java.util.ArrayList" %>
    <%@ page import="java.util.List" %>
    <%@ page import="com.bsol.hss.bean.Book" %>
    <%@ page import="com.bsol.hss.bean.Page" %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>书籍信息</title>
    </head>
    <body>
    <% 
       Page page1=(Page)request.getAttribute("page");//获取从Servlet传递过来的页面信息
        List<Book> books=page1.getBooks();//得到页面存储的书籍信息
        int pagenum=page1.getPagenum();   //得到当前页面为第几页
    %>
    	<div>
    		<big>所有书籍信息</big>
    	</div>
    	<div >
    		<table >
    			<% for(int i=0;i<books.size();i++){
    			Book book=books.get(i); %>
    				<tr>
    					<td>
    						<%= i+1 %>.<%=book.getBookname() %> 
    					</td>
    					<td>
    						库存：<%= book.getStock() %>
    					</td>
    				</tr>
    			<% } %>
    		</table>

jsp页面显示如下：

![20180602150329860][]

[20180602144151480]: /images/20220523/b2a5b37d8a674c42b3449678b81c72b9.png
[20180602150329860]: /images/20220523/adf5bf56b711451c9b7945158505eeee.png