一个简单的jsp+servlet实例，实现简单的登录

开发环境myeclipse+tomcat6

1、先创建web project，项目名为RegisterSystem，

2、在WebRoot 目录下创建login.jsp文件，只需修改body中的内容，如下所示：

<body>
    <form action="login">
    username:<input type="text" name="username"><br>
    password:<input type="password" name="pwd"><br>
    <input type="submit">
    </form>
  </body>

3、在scr目录下的com.ht.servlet编写AcountBean.java文件，代码如下：

package com.ht.servlet;

public class AccountBean {
 private String username = "";
 private String password = "";
 public String getPassword() {
  return password;
 }
 public void setPassword(String password) {
  this.password = password;
 }
 public String getUsername() {
  return username;
 }
 public void setUsername(String username) {
  this.username = username;
 }
}

4、在scr目录下的com.ht.servlet编写servlet类CheckAccount.java文件，代码如下：

package com.ht.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;

public class CheckAccount extends HttpServlet {

 @Override
 protected void doPost(HttpServletRequest req, HttpServletResponse resp)
   throws ServletException, IOException {
  doGet(req,resp);
 }

 @Override
 public void doGet(HttpServletRequest req, HttpServletResponse resp)
   throws ServletException, IOException {
  HttpSession session = req.getSession();
  AccountBean account = new AccountBean();
  String username = req.getParameter("username");
  String pwd = req.getParameter("pwd");
  account.setPassword(pwd);
  account.setUsername(username);
  if((username != null)&&(username.trim().equals("jsp"))) {
   if((pwd != null)&&(pwd.trim().equals("1"))) {
    System.out.println("success");
    session.setAttribute("account", account);
    String login_suc = "success.jsp";
    resp.sendRedirect(login_suc);
    return;
   }
  }
  String login_fail = "fail.jsp";
  resp.sendRedirect(login_fail);
  return;
 }
 
}
5、在WebRoot目录下编写success.jsp文件 成功后跳转

<body>
    <%
    AccountBean account = (AccountBean)session.getAttribute("account");
    %>
    username:<%= account.getUsername()%>
     <br>
     password:<%= account.getPassword() %>
  </body>

6、在WebRoot目录下编写fail.jsp文件 失败后跳转

<body>
   Login Failed! <br>
  </body>

7、修改web.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
 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_2_5.xsd">
  <welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>
 
  <servlet>
       <description>This is the description of my J2EE component</description>
       <display-name>This is the display name of my J2EE component</display-name>
         <servlet-name>CheckAccount</servlet-name>
       <servlet-class>com.ht.servlet.CheckAccount</servlet-class>
     </servlet>

     <servlet-mapping>
       <servlet-name>CheckAccount</servlet-name>
       <url-pattern>/login</url-pattern>
     </servlet-mapping>

 
</web-app>