web.xml (添加init-param)
1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app version="2.5" 3 xmlns="http://java.sun.com/xml/ns/javaee" 4 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 5 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 6 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> 7 <display-name></display-name> 8 <servlet> 9 <description>This is the description of my J2EE component</description> 10 <display-name>This is the display name of my J2EE component</display-name> 11 <servlet-name>GetInitParameterServlet</servlet-name> 12 <servlet-class>servlet.GetInitParameterServlet</servlet-class> 13 <init-param> 14 <param-name>username</param-name> 15 <param-value>admin</param-value> 16 </init-param> 17 <init-param> 18 <param-name>password</param-name> 19 <param-value>123456</param-value> 20 </init-param> 21 </servlet> 22 23 <servlet-mapping> 24 <servlet-name>GetInitParameterServlet</servlet-name> 25 <url-pattern>/servlet/GetInitParameterServlet</url-pattern> 26 </servlet-mapping> 27 <welcome-file-list> 28 <welcome-file>index.jsp</welcome-file> 29 </welcome-file-list> 30 </web-app>
index.jsp
1 <h1>获取初始化参数演示案例</h1> 2 <hr> 3 <a href="servlet/GetInitParameterServlet">获取初始化Servlet</a>
GetInitParameterServlet.java:
1 package servlet;
2
3 import java.io.IOException;
4 import java.io.PrintWriter;
5
6 import javax.servlet.ServletException;
7 import javax.servlet.http.HttpServlet;
8 import javax.servlet.http.HttpServletRequest;
9 import javax.servlet.http.HttpServletResponse;
10
11 public class GetInitParameterServlet extends HttpServlet {
12 private String username;
13 private String password;
14
15 public String getUsername() {
16 return username;
17 }
18
19 public void setUsername(String username) {
20 this.username = username;
21 }
22
23 public String getPassword() {
24 return password;
25 }
26
27 public void setPassword(String password) {
28 this.password = password;
29 }
30
31 /**
32 * Constructor of the object.
33 */
34 public GetInitParameterServlet() {
35 super();
36 }
37
38 /**
39 * Destruction of the servlet. <br>
40 */
41 public void destroy() {
42 super.destroy(); // Just puts "destroy" string in log
43 // Put your code here
44 }
45
46 /**
47 * The doGet method of the servlet. <br>
48 *
49 * This method is called when a form has its tag value method equals to get.
50 *
51 * @param request the request send by the client to the server
52 * @param response the response send by the server to the client
53 * @throws ServletException if an error occurred
54 * @throws IOException if an error occurred
55 */
56 public void doGet(HttpServletRequest request, HttpServletResponse response)
57 throws ServletException, IOException {
58
59 doPost(request, response);
60 }
61
62 /**
63 * The doPost method of the servlet. <br>
64 *
65 * This method is called when a form has its tag value method equals to post.
66 *
67 * @param request the request send by the client to the server
68 * @param response the response send by the server to the client
69 * @throws ServletException if an error occurred
70 * @throws IOException if an error occurred
71 */
72 public void doPost(HttpServletRequest request, HttpServletResponse response)
73 throws ServletException, IOException {
74
75 response.setContentType("text/html;charset=utf-8");
76 PrintWriter out = response.getWriter();
77 out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
78 out.println("<HTML>");
79 out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
80 out.println(" <BODY>");
81 out.println("<h2>用户名:"+this.getUsername()+"</h2>");
82 out.println("<h2>密码:"+this.getPassword()+"</h2>");
83 out.println(" </BODY>");
84 out.println("</HTML>");
85 out.flush();
86 out.close();
87 }
88
89 /**
90 * Initialization of the servlet. <br>
91 *
92 * @throws ServletException if an error occurs
93 */
94 public void init() throws ServletException {
95 this.setUsername(this.getInitParameter("username"));
96 this.setPassword(this.getInitParameter("password"));
97 }
98
99 }
时间： 2024-10-17 06:23:09