使用MVC添加书本信息

一：View addBook.jsp

 1 <%@page language="java" contentType="text/html; charset=utf-8"
 2     pageEncoding="utf-8" import="java.util.*" import="nuc.sw.EL.bean.EL"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
 7 <title>添加书本</title>
 8 </head>
 9 <body>
10 <form action="ELServlet" method="post">
11  <table  align="left" >
12  <tr>
13   <td>书名:</td>
14   <td><input type="text" name="bookName"></td>
15  </tr>
16  <tr>
17   <td>作者:</td>
18   <td><input type="text" name="authorName"></td>
19  </tr>
20  <tr>
21   <td>定价:</td>
22   <td><input type="text" name="bookPrice"></td>
23  </tr>
24  <tr>
25   <td><input type="submit" value="添加"></td>
26  </tr>
27 </table>
28 </form>
29 
30 
31   <% 
32         List all=(List)session.getAttribute("booklist");
33        if(all!=null)
34        {
35    %>
36    <table  align="right" border="1">
37          <caption>全部书籍信息</caption>
38          <tr>
39           <td>书名:</td>
40           <td>作者:</td>
41          <td>定价:</td>
42   </tr>
43   <% 
44         Iterator<EL> iterAlone=((ArrayList<EL>)session.getAttribute("booklist")).iterator();
45         Iterator<EL> iter=all.iterator();  
46         while(iter.hasNext()){
47           pageContext.setAttribute("book",iter.next());
48    %>
49      
50     <tr>
51       <td>${book.bookName} </td>
52       <td>${book.authorName} </td>
53       <td>${book.bookPrice} </td>
54    </tr>    
55 <%
56     }
57 %>
58 
59 </table>
60 <%
61 }       
62   %>
63 </body>
64 </html>

二：nuc.sw.EL.bean Book.java

 1 package nuc.sw.EL.bean;
 2 
 3 public class EL {
 4   private String bookName;
 5   private String authorName;
 6   private float bookPrice;
 7 public String getBookName() {
 8     return bookName;
 9 }
10 public void setBookName(String bookName) {
11     this.bookName = bookName;
12 }
13 public String getAuthorName() {
14     return authorName;
15 }
16 public void setAuthorName(String authorName) {
17     this.authorName = authorName;
18 }
19 public Float getBookPrice() {
20     return bookPrice;
21 }
22 public void setBookPrice(Float bookPrice) {
23     this.bookPrice = bookPrice;
24 }
25   
26 }

三：nuc.sw.EL.servlet RLServlet.java

 1 package nuc.sw.EL.servlet;
 2 
 3 import java.io.IOException;
 4 import java.util.ArrayList;
 5 import java.util.List;
 6 
 7 import javax.servlet.ServletException;
 8 import javax.servlet.http.HttpServlet;
 9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11 
12 import nuc.sw.EL.bean.EL;
13 
14 /**
15  * Servlet implementation class ELServlet
16  */
17 public class ELServlet extends HttpServlet {
18     private static final long serialVersionUID = 1L;
19        
20     /**
21      * @see HttpServlet#HttpServlet()
22      */
23     public ELServlet() {
24         super();
25         // TODO Auto-generated constructor stub
26     }
27 
28     /**
29      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
30      */
31     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
32         // TODO Auto-generated method stub
33         response.getWriter().append("Served at: ").append(request.getContextPath());
34     }
35 
36     /**
37      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
38      */
39     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
40         // TODO Auto-generated method stub
41         //doGet(request, response);
42         //接受表单传过来的数据，并封装到bean中
43         request.setCharacterEncoding("utf-8");
44         EL el=new EL();
45         el.setBookName(request.getParameter("bookName"));
46         el.setAuthorName(request.getParameter("authorName"));
47         el.setBookPrice(Float.parseFloat(request.getParameter("bookPrice")));
48         //request.setAttribute("el", el);
49         //集合模拟数据库，所以不需要连接数据库。
50         //新建集合 的话则一直都是新的，而且每个集合里都只有一个数据。所以需要把list放到一次会话中，即Session范围。
51         List<EL> list;
52         //从session中获取保存的信息。
53         //如果为空，则新建集合，书籍信息存入集合。
54         //Session为jsp的内置对象，如果在servlet中调用需要使用request.getSession().
55         if(request.getSession().getAttribute("booklist")==null){
56             list= new ArrayList<EL>();
57             list.add(el);
58         }
59         //假设不为空，直接获取list，并将书籍信息添加。
60     
61         else{
62             list=(ArrayList<EL>)request.getSession().getAttribute("booklist");
63             list.add(el);
64         }
65         //将集合放入session中
66         request.getSession().setAttribute("booklist", list);
67         //request.getRequestDispatcher("showBookInfo.jsp").forward(request, response);
68         //sevlet不擅长页面显示，所以就需要跳转。
69         request.getRequestDispatcher("addBook.jsp").forward(request, response);
70     }
71 
72 }

四：结果显示