状态会话bean

最新推荐文章于 2021-08-24 13:23:49 发布

转载最新推荐文章于 2021-08-24 13:23:49 发布 · 135 阅读

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原文链接：http://www.cnblogs.com/jinrize/archive/2012/04/15/2450759.html

本文介绍了一个使用Stateful EJB和Servlet的Java Web应用案例，演示了如何在Stateful会话Bean中存储和操作数据，并通过Servlet接收用户输入，更新数据并返回结果。

StatefulExample

NewBean.java

View Code

1 /*
2  * To change this template, choose Tools | Templates
3  * and open the template in the editor.
4  */
5 package beans;
6
7 import java.util.ArrayList;
8 import java.util.List;
9 import javax.annotation.PostConstruct;
10 import javax.ejb.Stateful;
11 import javax.ejb.LocalBean;
12
13 /**
14  *
15  * @author teemu
16  */
17 @Stateful
18 @LocalBean
19 public class NamesBean {
20
21     private List<String> names;
22
23     @PostConstruct
24     private void initialize(){
25         names = new ArrayList<String>();
26     }
27
28     public List<String> getNames() {
29         return names;
30     }
31
32     public void addName(String name) {
33         names.add(name);
34     }
35
36
37
38 }

index.jsp

View Code

1 <%@page contentType="text/html" pageEncoding="UTF-8"%>
2 <!DOCTYPE html>
3 <html>
4     <head>
5         <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
6         <title>JSP Page</title>
7     </head>
8     <body>
9          <form action="NamesServlet" method="get">
10             Name: <input type="text" name="name" /> <br/>
11             <input type="submit" value="Add name" />
12         </form>
13     </body>
14 </html>

NamesServlet.java

View Code

  1 /*
  2  * To change this template, choose Tools | Templates
  3  * and open the template in the editor.
  4  */
  5 package servlets;
  6
  7 import beans.NamesBean;
  8 import java.io.IOException;
  9 import java.io.PrintWriter;
10 import java.util.List;
11 import javax.ejb.EJB;
12 import javax.servlet.ServletException;
13 import javax.servlet.annotation.WebServlet;
14 import javax.servlet.http.HttpServlet;
15 import javax.servlet.http.HttpServletRequest;
16 import javax.servlet.http.HttpServletResponse;
17
18 /**
19  *
20  * @author teemu
21  */
22 @WebServlet(name = "NamesServlet", urlPatterns = {"/NamesServlet"})
23 public class NamesServlet extends HttpServlet {
24
25     @EJB
26     private NamesBean bean;
27     private List<String> list;
28
29     /**
30      * Processes requests for both HTTP
31      * <code>GET</code> and
32      * <code>POST</code> methods.
33      *
34      * @param request servlet request
35      * @param response servlet response
36      * @throws ServletException if a servlet-specific error occurs
37      * @throws IOException if an I/O error occurs
38      */
39     protected void processRequest(HttpServletRequest request, HttpServletResponse response)
40             throws ServletException, IOException {
41         response.setContentType("text/html;charset=UTF-8");
42         PrintWriter out = response.getWriter();
43         try {
44
45             bean.addName(request.getParameter("name"));
46             list = bean.getNames();
47
48             /*
49              * TODO output your page here. You may use following sample code.
50              */
51             out.println("<html>");
52             out.println("<head>");
53             out.println("<title>Servlet NamesServlet</title>");
54             out.println("</head>");
55             out.println("<body>");
56             out.println("<h1>List of names: </h1>");
57             for(String s:list)  {
58                 out.println(s+"<br>");
59             }
60             out.println("</body>");
61             out.println("</html>");
62         } finally {
63             out.close();
64         }
65     }
66
67     // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
68     /**
69      * Handles the HTTP
70      * <code>GET</code> method.
71      *
72      * @param request servlet request
73      * @param response servlet response
74      * @throws ServletException if a servlet-specific error occurs
75      * @throws IOException if an I/O error occurs
76      */
77     @Override
78     protected void doGet(HttpServletRequest request, HttpServletResponse response)
79             throws ServletException, IOException {
80         processRequest(request, response);
81     }
82
83     /**
84      * Handles the HTTP
85      * <code>POST</code> method.
86      *
87      * @param request servlet request
88      * @param response servlet response
89      * @throws ServletException if a servlet-specific error occurs
90      * @throws IOException if an I/O error occurs
91      */
92     @Override
93     protected void doPost(HttpServletRequest request, HttpServletResponse response)
94             throws ServletException, IOException {
95         processRequest(request, response);
96     }
97
98     /**
99      * Returns a short description of the servlet.
100      *
101      * @return a String containing servlet description
102      */
103     @Override
104     public String getServletInfo() {
105         return "Short description";
106     }// </editor-fold>
107 }

C:\Users\iltaek\Documents\NetBeansProjects\StatefullApp\StatefullApp-war\nbproject\build-impl.xml:752: The module has not been deployed.
See the server log for details.
BUILD FAILED (total time: 1 second)

转载于:https://www.cnblogs.com/jinrize/archive/2012/04/15/2450759.html