Redis single sign on system + voting system

Redis Single sign on System (SSO)

In distributed systems , There will be multiple services , After we log in to a service , When accessing other services , Don't want to log in again , You need a separate authentication system , We usually call it single sign on System , An authentication server is provided in this system , The service completes user authentication , In some small and medium-sized distributed systems , We usually use redis Store user authentication information , for example :

  Key code implementation

package com.jt;

import redis.clients.jedis.Jedis;

import java.util.UUID;

/**
 *  be based on redis Design and implementation of single sign on 
 * 1) After the user logs in successfully, the login status and other information will be stored in redis
 * 2) The user carries token Visit resources , The resource server should be based on token from redis Query user information 
 */
public class SSODemo01 {
    /**
     *  Perform login authentication , In the future, such services will be written to the authentication server 
     * @param username
     * @param password
     */
    static String doLogin(String username,String password){
       //1. Check the validity of the data ( Determine the user name , Whether the password is empty , The length of the password , Whether there are special symbols of numbers and letters )
       if(username==null||"".equals(username))
           throw new IllegalArgumentException(" User cannot be empty ");
       //2. Query user information based on user name , And determine whether the password is correct 
       if(!"jack".equals(username))
           throw new RuntimeException(" This user does not exist ");
       if(!"123456".equals(password))
           throw new RuntimeException(" Incorrect password ");
       //3. The user exists and the password is correct , Write user information to redis
        Jedis jedis = JedisDataSource.getConnection();
        String token= UUID.randomUUID().toString();
        jedis.hset(token, "username", username);
        jedis.hset(token, "permission", "sys:resource:create");
        jedis.expire(token, 10);// Set up key Effective time of 
        jedis.close();
       //4. take token Return to the client ( Future use response Object responds to the client ).
        return token;
    }
    static String token;

    /**
     *  Demonstrate the resource access process 
     * 1) Allow anonymous access ( No need to log in )
     * 2) Access after login ( certified )
     * 3) After logging in, you must have permission to access 
     */
    static Object doGetResource(String token){
        //1. check token Is it empty 
        if(token==null)
            throw new IllegalArgumentException(" Please log in first ");
        //2. be based on token Inquire about redis data , If there is corresponding data, it indicates that the user has logged in 
        // Mode one Jedis jedis=new Jedis("192.168.126.128", 6379);
        Jedis jedis = JedisDataSource.getConnection();
        String username=jedis.hget(token, "username");
        if(username==null)
            throw new RuntimeException(" login timeout , Please login again ");
        String permission=jedis.hget(token, "permission");
        jedis.close();
        //3. Check whether the user has access to the resource , If so, allow access to 
        if(!"sys:resource:create".equals(permission))
            throw new RuntimeException(" You don't have access to this resource ");
        //4. Returns the resource to access .
        return " Resource access succeeded ！";
    }
    public static void main(String[] args) {
        //1. Login operation ( User authentication )
        token=doLogin("jack", "123456");
        System.out.println(token);
        //2. carry token Access resource server 
        Object result=doGetResource(token);
        System.out.println(result);
    }
}

Simple voting system

In many systems design , There will be an activity design , Before starting an activity , We can conduct a survey on the support for this activity first , For example, design a voting system based on this activity , for example :

package com.jt;

import com.jt.JedisDataSource;
import redis.clients.jedis.Jedis;

import java.util.Set;

/**
 *  Design of a simple voting system based on an activity 
 * 1) The voting data is stored in redis (key For the event id, Multiple users id Set )
 * 2) The same user cannot vote more than once 
 * 3) Specific business operations ( vote , Get the total number of votes , Check whether you have voted , Cancel the vote , Get who voted )
 */
public class VoteDemo01 {

    /**
     *  Get a vote on who performed the event 
     * @param activityId
     * @return
     */
    static  Set<String> doGetMembers(String activityId){
        //1. Establishing a connection 
        Jedis jedis = JedisDataSource.getConnection();
        //2. Get the total number of votes for the current activity 
        Set<String> smembers = jedis.smembers(activityId);
        //3. Release resources 
        jedis.close();
        return smembers;
    }
    /**
     *  Gets the total number of votes for the specified event 
     * @param activityId
     * @return
     */
    static Long doCount(String activityId){
        //1. Establishing a connection 
        Jedis jedis = JedisDataSource.getConnection();
        //2. Get the total number of votes for the current activity 
        Long count=jedis.scard(activityId);
        //3. Release resources 
        jedis.close();
        return count;
    }
    /**
     *  Execute voting operation 
     * @param activityId
     * @param userId
     */
    static void doVote(String activityId,String userId){
        //1. Establishing a connection 
        Jedis jedis = JedisDataSource.getConnection();
        //2. Executive voting 
        //2.1 Check whether you have voted 
        Boolean flag = jedis.sismember(activityId, userId);
        //2.2 Execute a vote or cancel a vote 
        if(flag){
            // If you have voted , Vote again and cancel the vote 
            jedis.srem(activityId, userId);
        }else{
            // If you have not cast a vote, you will vote 
            jedis.sadd(activityId, userId);
        }
        //3. Release resources 
        jedis.close();
    }
    public static void main(String[] args) {
        String activityId="101";
        String userId1="1";
        String userId2="2";
        String userId3="3";
        // Execute voting action 
        doVote(activityId, userId1);
        doVote(activityId, userId2);
        doVote(activityId, userId3);
        // Get the total number of votes 
        Long aLong = doCount(activityId);
        System.out.println(" Total votes ："+aLong);
        // Get the members who voted 
        Set<String> members= doGetMembers(activityId);
        System.out.println(" Number of votes ："+members);
    }

}