1.登录项目改造成Servlet版本
(1)login.jsp文件和4.4基本一样，将action中的地址改为LoginServlet：
<form action="${pageContext.request.contextPath }/LoginServlet" method="post">即将之前login_action.jsp的逻辑代码放入Servlet中。
(2)LoginServlet.java。
package cn.cszyedu.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import cn.cszyedu.po.User;
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置编码
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取请求参数
String userName = request.getParameter("userName");
String userPwd = request.getParameter("userPwd");
User user=new User(userName, userPwd, null,null,null);
//获取session对象
HttpSession session = request.getSession();
if(userName==null||userPwd==null){
//request.setAttribute("message", "用户名或密码为空");
response.sendRedirect(request.getContextPath()+"/jsp/login.jsp");
}else if(userName.equals("lan") && userPwd.equals("123")){
session.setAttribute("userName", userName);
session.setAttribute("userPwd", userPwd);
// session.setAttribute("user", user);
request.getRequestDispatcher("/jsp/user.jsp").forward(request, response);
}else{
//request.setAttribute("message", "用户名或密码错误");
response.sendRedirect(request.getContextPath()+"/jsp/login.jsp");
}
}
}
LoginServlet登录成功页面跳转到user.jsp。
(3)web.xml文件中配置LoginServlet
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>cn.cszyedu.servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
</web-app>
2.用Servlet实现留言板
(1)jsp/publish.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>发表文章</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<style type="text/css">
table {
border-color: #aaaaaa;
}
.td_01 {
width: 500px;
height: 50px;
text-align: center;
font-weight: bold;
font-size: 20pt;
background-color: #cccccc;
color: #222222;
}
.td_02{
width: 180px;
text-align: center;
}
.td_03{
height: 100px;
text-align: center;
}
</style>
</head>
<body>
<form action="${pageContext.request.contextPath}/PublishServlet" method="post">
<table border="1" cellspacing="0" align="center">
<tr>
<td colspan="2" class="td_01">发表文章</td>
</tr>
<tr>
<td class="td_02">文章类型：</td>
<td>
<select name="articType">
<option value="程序设计">程序设计</option>
<option value="军事">军事</option>
<option value="艺术设计">艺术设计</option>
<option value="传统文化">传统文化</option>
<option value="篮球体育">篮球体育</option>
<option value="世界地图">世界地图</option>
</select>
</td>
</tr>
<tr>
<td class="td_02">文章标题：</td>
<td>
<input type="text" name="articTitle"/>
</td>
</tr>
<tr>
<td class="td_03">文章内容：</td>
<td>
<textarea rows="10" cols="41" name="articContent"></textarea>
</td>
</tr>
<tr>
<td class="td_02">您已发表的文章数：</td>
<td>${sessionScope.count }篇</td>
</tr>
<tr >
<td colspan="2" align="center">
<input type="submit" value="确定发表">
<input type="button" onclick="out()" value="返回首页">
<input type="button" onclick="back()" value="返回用户界面">
</td>
</tr>
</table>
</form>
<script type="text/javascript">
function out(){
window.location.href="../index.jsp";
}
//var path = ${pageContext.request.contextPath };
function back(){
//alert(1);
window.location.href="./user.jsp";
}
</script>
</body>
</html>
(2)PublishServlet.java
package cn.cszyedu.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.cszyedu.po.Articles;
@WebServlet(description = "PublishServlet", urlPatterns = { "/PublishServlet" })
public class PublishServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取参数
String articType = request.getParameter("articType");
String articTitle = request.getParameter("articTitle");
String articContent = request.getParameter("articContent");
// User user = (User) request.getSession().getAttribute("user");
// String articAuthor = user.getUserName();
if(articTitle==null||articTitle==""||articContent==null||articContent==""){
request.setAttribute("message", "文章标题和文章内容不能为空");
request.getRequestDispatcher("jsp/publish.jsp").forward(request, response);
}else{
Articles article=new Articles(null,articType,articTitle,articContent,request.getSession().getAttribute("userName").toString(),new Date());
request.setAttribute("article", article);
request.getRequestDispatcher("jsp/user.jsp").forward(request, response);
// response.sendRedirect(request.getContextPath()+"/jsp/user.jsp");
}
//System.out.println(articType);
}
}
效果图如下：
