Easy to master SSO single sign on, see this article

One 、 introduction

as everyone knows , A web system , The most basic function is login , As a JAVA The programmer , From write down Hello Word In the process of becoming a technological bull , Login function is not necessarily the most written , But it must be the most common , This article briefly introduces SSO The concept and principle of , And then use SpringBoot A simple SSO System . System use token In the form of , rely on cookie carry token towards sso The server validates , Allow access to the requested address after verification .

Two 、SSO Introduce

as everyone knows , When we first started writing business , There may be only one module , But as the development time increases , There will be more and more code , It will be very redundant , Then at this time, we will split the code into small modules one after another , Every module is a system , For example, we have built an e-commerce system , He has a shopping cart system , Commodity system , Purchase system, etc , Then after we log in , When accessing another system , If you want to log in again , It will be very troublesome , So here we introduce SSO Single sign on System , As long as a system logs in successfully , The other system doesn't need to log in .

3、 ... and 、 Common examples

The e-commerce we use most in our daily life APP It's probably Taobao , Here we use Taobao as an example

First , We log into the main interface of Taobao , And log in

Click to jump to Taobao main interface

ad locum , We can see the domain name of Taobao ,taobao.com, This is the time , Let's take a look at the shopping cart , We will find that , After entering the shopping cart menu , The domain name of the website has changed

that , We can know , ad locum , Single sign on occurs , As long as we log in to the main interface , Accessing other systems , Like a shopping cart , Favorites , We are also logged in , Then there is no need to do it again , This saves a lot of things , So today we will learn how to do this .

3、 ... and 、SSO Code implementation

At present, there are two common login , One is to store user information session in , Judge when the mirror is operating session Whether there is , Another is through token To judge . We know session It's not shared , that , Can we put token There is cookie in , When a system logs in , When accessing another system , Let's judge token Whether it is right , If correct , Just let it go , error , The intercept , Here we simply implement

Assign a domain name to this machine

Before you write the code , We need to assign a domain name to our host first , This will facilitate our next work

Let's check our LAN first ip

Turn on my computer , Find this path ：C:\Windows\System32\drivers\etc

Then open the host file , Compiling , The domain name can be chosen by yourself , Save and exit after finishing

Write code

We need two services to simulate , So we first set up the following two files , And then to client Set port 8081,server Set up 8082

then , Let's add the rest of the code , First, client Under the

User class

package com.znb.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    
    private int id;
    private String username;
    private String password;
}

LoginCacheUtil

package com.znb.utils;



import com.znb.pojo.User;

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

public class LoginCacheUtil {
    
    public static Map<String , User> loginUser = new HashMap<>();
}

LoginController

package com.znb.controller;


import com.znb.pojo.User;
import com.znb.utils.LoginCacheUtil;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.thymeleaf.util.StringUtils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.HashSet;
import java.util.Optional;
import java.util.Set;
import java.util.UUID;


@Controller
@RequestMapping("/login")
public class LoginController {
    
    private static Set<User> dbUsers;
    static {
    
        dbUsers = new HashSet<>();
        dbUsers.add(new User(0,"xiaoyan","000000"));
        dbUsers.add(new User(1,"tangsan","000000"));
        dbUsers.add(new User(2,"yecheng","000000"));
    }

    @PostMapping
    public String doLogin(User user, HttpSession session, HttpServletResponse response){
    


        // Simulate finding users in the database by logging in user name and password from the database 
        Optional<User> first = dbUsers.stream().filter(dbUser -> dbUser.getUsername().equals(user.getUsername()) &&
                dbUser.getPassword().equals(user.getPassword()))
                .findFirst();
        // Judge whether the user logs in 
        if(first.isPresent()){
    
            // Save the user's login information 
            String token = UUID.randomUUID().toString();
            Cookie cookie = new Cookie("TOKEN",token);
            cookie.setDomain("codeicee.com");
            response.addCookie(cookie);
            LoginCacheUtil.loginUser.put(token,first.get());
        }
        else{
    
            // Login failed 
            session.setAttribute("msg"," Wrong user name or password ");
            return "login";
        }
        // Redirect to target Address 
        return "index" ;
    }

    @GetMapping("info")
    @ResponseBody
    public ResponseEntity<User> getUserInfo(String token){
    
        if(!StringUtils.isEmpty(token)){
    
            User user = LoginCacheUtil.loginUser.get(token);
            return ResponseEntity.ok(user);
        }else {
    
            return new ResponseEntity<>(null, HttpStatus.BAD_REQUEST);
        }
    }
}

ViewController

package com.znb.controller;


import com.znb.pojo.User;
import com.znb.utils.LoginCacheUtil;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.thymeleaf.util.StringUtils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpSession;

/** *  Page Jump logic  */
@Controller
@RequestMapping("/view")
public class ViewController {
    


    @RequestMapping("/")
    public String index(){
    
        return "index";
    }


    /** *  Go to the login page  * @return */
    @GetMapping("/login")
    public String toLogin(@RequestParam(required = false,defaultValue = "")String target,
                          HttpSession session,
                          @CookieValue(required = false,value = "TOKEN")Cookie cookie){
    

        if(StringUtils.isEmpty(target)){
    
            target = "http://www.codeicee.com:8081";
        }
        // If the logged in user visits the login page again , Need to redirect 
        if(cookie != null){
    
            //token
            String value = cookie.getValue();
            User user = LoginCacheUtil.loginUser.get(value);
            if(user != null){
    
                return "product";
            }
        }


        // Redirect address 
        session.setAttribute("target",target);
        return "login";
    }
}

index

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1> home page </h1>
</body>
</html>

login

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8"/>
    <title>Login Module</title>
</head>
<body>
<h1> Welcome to the login page </h1>
<p style="color: red;" th:text="${session.msg}"></p>
<form action="/login" method="POST">
     user name ：<input name="username" value=""/>
     password ：<input name="password" value=""/>
    <button type="submit"> Sign in </button>
</form>
</body>
</html>

product

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1> product </h1>
</body>
</html>

And then there was server

ViewController

package com.znb.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CookieValue;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.client.RestTemplate;
import org.thymeleaf.util.StringUtils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpSession;
import java.util.Map;

@Controller
@RequestMapping("/view")
public class ViewController {

    @Autowired
    private RestTemplate restTemplate;

    private final String USER_INFO_ADDRESS = "http://codeicee.com:8081/login/info?token=";


    @GetMapping("/index")
    public String toIndex(@CookieValue(required = false,value = "TOKEN") Cookie cookie,
                          HttpSession session){
        if(cookie != null){
            String token = cookie.getValue();
            if(!StringUtils.isEmpty(token)){
                Map result = restTemplate.getForObject(USER_INFO_ADDRESS + token,Map.class);
                session.setAttribute("loginUser",result);
            }
        }
        return "index";
    }
}

Start both projects , We will find that , When client After logging in server Your login was also successful