开发环境idea2018.1+tomcat9.0
一、先创建web project
在菜单栏选File->New->Project->Java Enterprice
SDK ，java EE version， Application server(选择配置好的tomcat版本)，默认值，Next
选择create project from project，Next
project name可以随便起一个，Finish
二.编写控制器代码
1、在src目录下新建包，我的是com.cmcc.servlet
2、在包com.cmcc.servlet下编写AcountBean.java文件，代码如下：
package com.cmcc.servlet;
public class AccountBean {
private Stringusername ="";
private Stringpassword ="";
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;
}
}
3、在包com.cmcc.servlet下编写servlet类CheckAccount.java文件，代码如下：
package com.cmcc.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 CheckAccountextends 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;
}
}
4、创建jsp页面。在web目录下新建一个jsp页面，选中web文件夹右键，new，jsp/jspx，名称为login，代码如下：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page language="java" import="com.cmcc.servlet.*"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<body>
<form action="login">
username:<input type="text" name="username"><br>
password:<input type="password" name="pwd"><br>
<input type="submit">
</form>
</body>
</body>
</html>
5、创建jsp页面。在web目录下新建一个jsp页面，选中web文件夹右键，new，jsp/jspx，名称为sucess，成功后跳转，代码如下：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page language="java" import="com.cmcc.servlet.*"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<body>
<%
AccountBean account = (AccountBean)session.getAttribute("account");
%>username:<%= account.getUsername()%><br>
password:<%= account.getPassword() %></body>
</body>
</html>
6、创建jsp页面。在web目录下新建一个jsp页面，选中web文件夹右键，new，jsp/jspx，名称为fail，登录失败后跳转，代码如下：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
Login Failed!<br>
</body>
</html>
7、修改web.xml配置文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app 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_4_0.xsd"
version="4.0">
<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.cmcc.servlet.CheckAccount</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>CheckAccount</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
</web-app>
三.运行项目
选择使用tomcat运行项目
可以看到浏览器自动打开该项目的欢迎页面，即logoin.jsp页面（网址的端口可能会不一样）
账号输入jsp，密码为1，成功跳转（账号密码在CheckAccount.java中设置）
参考出处：
