JavaWeb_利用Servlet处理注册登录请求

利用Servlet处理注册登录请求

　　程序结构

　　 JavaWeb_利用Servlet处理注册登录请求

<%@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" method="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>

<%@ 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

<%@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" method="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>

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.servlet;

import java.io.IOException;

import javax.servlet.ServletContext;

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 com.Gary.model.User;

import com.Gary.util.DBUtil;

@WebServlet("/login_do")

public class LoginServlet extends HttpServlet {

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        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;

            //获取到application对象

            ServletContext application = this.getServletContext();

            //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

            request.getSession().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);

        }

    }

}

LoginServlet.java

package com.Gary.servlet;

import java.io.IOException;

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 com.Gary.util.DBUtil;

@WebServlet("/register_do")

public class RegisterServlet extends HttpServlet {

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        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);

        }

    }

}

RegisterServlet.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

　　通过RegisterServlet.java和LoginServlet.java来处理注册登录请求

用户注册

　　通过户数据模型驱动User,java和DBUtild.java中对数据进行本地处理

　　登录同理注册

<form action="register_do" method="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>

　　RegisterServlet.java通过doPost()方法处理注册信息

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        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);

        }

    }

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JavaWeb_利用Servlet处理注册登录请求

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