JSP简单登录窗口

本代码要求在Tomcat配置完成下运行

部分文件结构

 User代码段

package mybean;

public class User {
    private String name;
    private String pass;
    public User(){
        this.name="";
        this.pass="";
    }
    public void setName(String name){
        this.name=name;
    }
    public void setPass(String pass){
        this.pass=pass;
    }
    public String getName(){
        return name;
    }
    public String getPass(){
        return pass;
    }
}

LoginCheckServlet代码段

package Servlet;

import mybean.User;
import org.apache.commons.beanutils.BeanUtils;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.InvalidPropertiesFormatException;
import java.util.Map;

@WebServlet(name = "LoginCheckServlet", value = "/LoginCheckServlet")
public class LoginCheckServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("/text/utf-8;charaset=utf-8");
        Mapparas=request.getParameterMap();
        User user=new User();
        try{
            BeanUtils.populate(user,paras);
            if (user.getName().equals("张三")&&user.getPass().equals("123"))
            {

                request.getSession().setAttribute("user",user);
                request.getRequestDispatcher("/main.jsp").forward(request,response);
            }
            else
            {
               if(!user.getName().equals("张三"))
               {
                   request.getSession().setAttribute("name-err","用户名输入有误");
                   response.sendRedirect(request.getContextPath()+"/login.jsp");
                   return;
               }
                if(!user.getPass().equals("123"))
                {
                    request.getSession().setAttribute("pass-err","密码名输入有误");

                    response.sendRedirect(request.getContextPath()+"/login.jsp");
                }
            }
        }catch (IllegalAccessException e){
            e.printStackTrace();
        }catch (InvocationTargetException e){
            e.printStackTrace();
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
             this.doGet(request,response);
    }
}

login代码段

<%--
  Created by IntelliJ IDEA.
  User: 16205
  Date: 2021/10/15
  Time: 10:44
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    
    
        color
    


 method="post">
    username:
    <%=session.getAttribute("name-err")==null?"":session.getAttribute("name-err")%>

    password:
    

    
    

 main代码段

<%@ page import="mybean.User" %><%--
  Created by IntelliJ IDEA.
  User: 16205
  Date: 2021/10/15
  Time: 11:11
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


欢迎:<%=((User)session.getAttribute("user")).getName()%>

运行结果