自己为了测试servlet，用MyEclipse2015写了一个简单的登录程序。
1.登录页面index.jsp.
1 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
2 <%
3 String lUserName = (String)session.getAttribute("iUserName");
4 %>
5
6 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
7 <html>
8 <head>
9 <meta charset="utf-8">
10 <title>My JSP ‘index.jsp‘ starting page</title>
11 <meta http-equiv="pragma" content="no-cache">
12 <meta http-equiv="cache-control" content="no-cache">
13 <meta http-equiv="expires" content="0">
14 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
15 <meta http-equiv="description" content="This is my page">
16 </head>
17
18 <body>
19 <%
20 if (lUserName != ""&&lUserName!=null) {
21 %>
22 欢迎光临，<%=lUserName%>
23 <%
24 } else {
25 %>
26 <form name="loginfrm" action="loginserv" method="post">
27 用户名：<input type="text" name="username" value="zhangsan"><br>
28 密码:<input type="text" name="password" value="mm123456"><br>
29 <input type="submit" value="登录">
30 </form>
31 <%
32 }
33 %>
34 </body>
35 </html>
2.用模版写了一个servlet程序loginserv.java.
1 package com.kaly.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 loginserv extends HttpServlet {
12 public void doGet(HttpServletRequest request, HttpServletResponse response)
13 throws ServletException, IOException {
14 doPost(request, response);
15 }
16
17 public void doPost(HttpServletRequest request, HttpServletResponse response)
18 throws ServletException, IOException {
19 request.setCharacterEncoding("utf-8");
20 response.setContentType("text/html);charset=utf-8");
21 String getUser=request.getParameter("username");
22 String getpassword=request.getParameter("password");
23 PrintWriter pw=response.getWriter();
24 pw.print(getUser);
25 }
26
27 }
这是一个很简单的程序，在收到请求后，把用户名打印出来。
3.运行出现问题：The requested resource is not available.
4.查找咨询，没有解决。后来查看web.xml。
1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app version="3.0" 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 http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> 6 <servlet> 7 <description>This is the description of my J2EE component</description> 8 <display-name>This is the display name of my J2EE component</display-name> 9 <servlet-name>loginserv</servlet-name> 10 <servlet-class>com.kaly.servlet.loginserv</servlet-class> 11 </servlet> 12 13 <servlet-mapping> 14 <servlet-name>loginserv</servlet-name> 15 <url-pattern>/servlet/loginserv</url-pattern> 16 </servlet-mapping> 17 18 </web-app>
因为这些都是自动生成，没有想到过会出现问题。不过记起以前写这个程序时<url-pattern>节点只是在<servlet-name>节点内容前多一个"/"，尝试将其改为/loginserv，重启服务运行页面。一些正常。
总结：这应该是这种问题出现的其中一种解决途径。
时间： 2024-08-02 19:19:45