Additional: [login information storage] and [login status verification]; (including: summarizing all the contents of [login information storage] and [login status verification] so far;)

explain ：

（1） Why did you write this blog ？：

          ●  stay 【27： The third chapter ： Developing a pass service ：10：【 register / Sign in 】 Interface ： register / Sign in OK after , Send the user session information （uid,utoken） Save to redis and cookie in ;】 in , Register in development / When logging into the interface , We put the user session related information （uid and utoken）, They exist separately 【 Front end browsing cookie】 and 【 Back end redis】;

          ● Obviously , This is for all the following “ Need to verify user login ” Prepare for the situation ; however , This is the practice in the case of distributed microservices ; and , I am relatively unfamiliar with this ;

          ● therefore , In order to better understand the above practice ;;; Feeling , Need to summarize , All the contents about login verification encountered before ;

（2） The content of this blog , Understanding may be biased 、 Incomplete 、 Even the wrong place ;

Catalog

One ：【（6） Enterprise portal case , Project development knowledge points ;】： A simple Servlet project ;

Two ：【（12） MOOC OA System （Mybatis Project case , More important ！）】 ： One is used Mybatis Of Servlet project ;

3、 ... and ：【 （17）SSM Develop Book Review Network 】： One SSM project ;

Four ：【（19）Spring Boot E-commerce projects 】： One Spring Boot project ;

5、 ... and ： The solution of this project ;

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One ：【（6） Enterprise portal case , Project development knowledge points ;】： A simple Servlet project ;

The project is simple , Login verification is not used ;

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Two ：【（12） MOOC OA System （Mybatis Project case , More important ！）】 ： One is used Mybatis Of Servlet project ;

The basic logic of this project is ：

          ●  When logging in , It stores the information of the logged in user session in ;

          ●  In some places where you need to have a current login user , It will try from session Get the current login user information in ;;; If session There is login user information in , Everything OK;;; If not , The null pointer exception will be reported ;

（1） Front end landing page , enter one user name / After the password , If login is successful , Just put the information of the currently logged in user , It's stored in Session In the object ;

          ●  After the above login is successful , Will jump to the page ;;;

          ●  then , Jump to the new page , It will automatically call other interfaces ;

（2）  then , In other places where you need the information of the currently logged in user , In this interface , Will try to start from session Get the current login user information in ;;; If session There is login user information in , Everything OK;

（3） natural , When you sign out here , Is to put Session Delete the data of user information in （ Or just put that session Get reimbursed ）;

（4） then , If at this time , Let's visit those 【 need session in , Interface with user information 】 when , Interface to try from session The statement to obtain user information in will report a null pointer exception ;

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3、 ... and ：【（17）SSM Develop Book Review Network 】： One SSM project ;

（1） register OK after , It just jumps to the login page ;

（2） After successful login , It stores user information in session In the object ;

（3） then , In other interfaces that require user login , from session Get user information in the object ;

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Four ：【（19）Spring Boot E-commerce projects 】： One Spring Boot project ;

（1） After successful login , User information is also stored in session In the object ;

（2） then , In other interfaces that require user login , from session Get user information in the object ;;; If you can get , Everything goes smoothly ;;; If not , Throw an exception ;

 

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5、 ... and ： The solution of this project ;

Simply speaking , This project is used to save user login information at the back end , There is no session, But use Redis; 

however , Some distributed micro service projects , On the back end, it seems that the information is still stored session Medium , This seems to involve sharing session Wait for the content ;

Own to share session The content such as , Do not know much about , At present, there is no need to see ; When needed later , It's not too late to look for relevant information ;