JavaWeb_(session和application)用户登录注册模板_进阶版

 

 

　　用户登录注册模板_基础版　　传送门

 

用户登录注册模板进阶版

　　添加了获得获得当前登录用户信息及存储登录人数

　　用户登录后，在首页、注册页、登录页显示登录用户信息和存储登录人数信息

 

　　目录结构　　

 

 

<%@page import="com.Gary.model.User"%>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>

<%
Object o = session.getAttribute("user");
if(o!=null){
    User user = (User)o;
    out.println("当前登录用户："+user.getUsername()+"<br/>");
}
%>

<%
Object o2 = application.getAttribute("userNumber");
if(o2!=null){
    out.println("当前登录用户"+o2+"个<br/>");
}
%>

<a href="login.jsp">登录</a>
<a href="register.jsp">注册</a>

</body>
</html>
index.jsp

 

<%@page import="com.Gary.model.User"%>
<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>
<%
Object o = session.getAttribute("user");
if(o!=null){
    User user = (User)o;
    out.println("当前登录用户："+user.getUsername()+"<br/>");
}
%>

<%
Object msg = request.getAttribute("message");
if(msg!=null)
    out.println(msg);
%>

登录<hr>
<form action="login_do.jsp" methon="post">
用户名：<input type="text" name="username" /><br/>
密码    ：<input type="password" name="password" /><br/>

<input type="submit" value="登录"/>
</form>
</body>
</html>
login.jsp

 

<%@page import="com.Gary.util.DBUtil" %>
<%@page import="com.Gary.model.User" %>
<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>
<%
String username = request.getParameter("username");
String password = request.getParameter("password");

User user = DBUtil.verifyAccount(username,password);
if(user==null){
//    out.println("登录失败，用户名或密码错误");
    request.setAttribute("message","登录失败，用户名或密码错误");
    request.getRequestDispatcher("login.jsp").forward(request,response);
}else{
//    out.println("登录成功");
    int number = 0;
    
    //第一次登录用户时if不瞒住,number=0
    if(application.getAttribute("userNumber")!=null){
        number = (Integer)application.getAttribute("userNumber");
    }
    
    //登录过一个用户后在原基础number上进行++
    number++;

    application.setAttribute("userNumber",number);
    
    //通过seesion的setAttribute传递数据
    session.setAttribute("user", user);
    //登录请求的转发,将数据传递给personCenter.jsp页面
    request.getRequestDispatcher("personCenter.jsp").forward(request,response);
}
%>
</body>
</html>
login_do.jsp

 

<%@page import="com.Gary.model.User"%>
<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>
<%
Object o = session.getAttribute("user");
if(o!=null){
    User user = (User)o;
    out.println("当前登录用户："+user.getUsername()+"<br/>");
}
%>

<%
Object msg = request.getAttribute("message");
if(msg!=null)
    out.println(msg);
%>

<form action="register_do.jsp" methon="post">
用户名：<input type="text" name="username" /><br/>
密码：    <input type="password" name="password" /><br/>
年龄：    <input type="text" name="age" /><br/>
性别：男<input type="radio" name="sex" value="男" />女<input type="radio" name="sex" value="女"/><br/>

<input type="submit" value="注册"/>
</form>

</body>
</html>
register.jsp

 

<%@ page import="com.Gary.util.DBUtil" %>
<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>
<%

String username = request.getParameter("username");
String password = request.getParameter("password"); 
int age = Integer.parseInt(request.getParameter("age"));
String sex = request.getParameter("sex");

boolean isSuccess = DBUtil.addUser(username,password,age,sex);

//使用请求转发
if(isSuccess){
    request.setAttribute("message", "注册成功，请登录");
    //通过getRequestDispatcher传递路径将请求转发给login.jsp
    request.getRequestDispatcher("login.jsp").forward(request,response);
}else{
    request.setAttribute("message", "注册失败，用户名重复");
    //通过getRequestDispatcher传递路径将请求转发给login.jsp
    request.getRequestDispatcher("register.jsp").forward(request,response);
}

// if(isSuccess){
//     out.println(username);
//      out.println("<font color='green'>注册成功</font>");
// }else{
//     out.println(username);
//     out.println("<font color='red'>注册失败</font>");
// }
%>
</body>
</html>
register_do.jsp

 

<%@ page import="com.Gary.model.User" %>
<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
</head>
<body>
<%
//通过session的getAttribute进行访问
User user = (User)session.getAttribute("user");
%>

用户名：<%=user.getUsername()%><br/>
年龄：<%=user.getAge()%><br/>
性别：<%=user.getSex()%><br/>
</body>
</html>
personCenter.jsp

 

package com.Gary.model;

public class User {
    private String username;
    private String password;
    private int age;
    private String sex;
    public User(String username, String password, int age, String sex) {
        super();
        this.username = username;
        this.password = password;
        this.age = age;
        this.sex = sex;
    }
    
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    
    
    
}
User.java

 

package com.Gary.util;

import java.util.HashMap;
import java.util.Map;

import com.Gary.model.User;


public class DBUtil {
    
    private static Map<String ,User>db = new HashMap<String,User>();
    
    public static boolean addUser(String username,String password,int age,String sex) {
        //TODO
        
        if(db.containsKey(username)) {
            return false;
        }else {
            User user=new User(username,password,age,sex);
            db.put(username, user);
            return true;
        }
    }
    
    //账号校验
    public static User verifyAccount(String username,String password) {
        if(db.containsKey(username)) {
            User user = db.get(username);
            if(user.getPassword().equals(password)) {
                return user;
            }else {
                return null;
            }
        }
        return null;
    }
}
DBUtil.java

 

 

获得当前用户登录

　　注册时通过session的setAttribute传递数据

<%
String username = request.getParameter("username");
String password = request.getParameter("password");

User user = DBUtil.verifyAccount(username,password);
if(user==null){
//    out.println("登录失败，用户名或密码错误");
    request.setAttribute("message","登录失败，用户名或密码错误");
    request.getRequestDispatcher("login.jsp").forward(request,response);
}else{
//    out.println("登录成功");
    //通过seesion的setAttribute传递数据
    session.setAttribute("user", user);
    //登录请求的转发,将数据传递给personCenter.jsp页面
    request.getRequestDispatcher("personCenter.jsp").forward(request,response);
}
%>

 

　　personCenter中通过Session对存储user键值进行访问

<%
//通过session的getAttribute进行访问
User user = (User)session.getAttribute("user");
%>

 

　　index.jsp、login.jsp、register.jsp中添加session会话获得当前登录用户

<%
Object o = session.getAttribute("user");
if(o!=null){
    User user = (User)o;
    out.println("当前登录用户："+user.getUsername()+"<br/>");
}
%>

 

 

存储登录人数

　　当用户web启动的时候会创建application内置对象，当用户关闭web时销毁application内置对象

　　application存放的数据通常是所有客户端所共享的数据

　　

　　当用户注册时，login_do.jsp中定义一个number变量用来存储登录人数，每次有用户进行登录时，使number数量+1

<%
String username = request.getParameter("username");
String password = request.getParameter("password");

User user = DBUtil.verifyAccount(username,password);
if(user==null){
//    out.println("登录失败，用户名或密码错误");
    request.setAttribute("message","登录失败，用户名或密码错误");
    request.getRequestDispatcher("login.jsp").forward(request,response);
}else{
//    out.println("登录成功");
    int number = 0;
    
    //第一次登录用户时if不瞒住,number=0
    if(application.getAttribute("userNumber")!=null){
        number = (Integer)application.getAttribute("userNumber");
    }
    
    //登录过一个用户后在原基础number上进行++
    number++;

    application.setAttribute("userNumber",number);
    
    //通过seesion的setAttribute传递数据
    session.setAttribute("user", user);
    //登录请求的转发,将数据传递给personCenter.jsp页面
    request.getRequestDispatcher("personCenter.jsp").forward(request,response);
}
%>

 

　　在index.jsp中添加application应用

<%
Object o2 = application.getAttribute("userNumber");
if(o2!=null){
    out.println("当前登录用户"+o2+"个<br/>");
}
%>

 

posted @ 2019-01-20 13:34  Cynical丶Gary  阅读(1900)  评论(0)  编辑  收藏  举报