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
时间： 2025-01-05 14:32:56