Springboot project built from zero

The first is the four recent basic folders (I won't explain too much)

Create a mapper.xml path in resources that is the same as the mapper interface. If the path is the same, it does not need to be configured. If it is different, it needs to be configured. Here is the mybatis plus configuration for the. yaml file
Represented as mapper.xml file under mapper

mybatis-plus:
  mapper-locations: classpath*:/mapper/**Mapper.xml

The most basic database configuration. If the front-end uses thymeleaf, you also need to configure it

spring:
  thymeleaf:
    mode: HTML
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/yqt?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai
    username: root
    password: *******

Log configuration (there are many types of logs)

logging:
  level:
    root: info
    com.crz: debug
  file:
    path: log/blog-dev.log

The overall configuration of application.yaml (it is still the most basic, and shiro and redis will be added to the project later)

spring:
  thymeleaf:
    mode: HTML
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/yqt?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai
    username: root
    password: 201317201317


logging:
  level:
    root: info
    com.crz: debug
  file:
    path: log/blog-dev.log

Creation of entity class (one to one to many to many)

One to one correspondence between entity classes and database tables
Before creating tables, you must find out the relationship between tables

exception handling

Log processing

(if necessary for later log processing, you need to copy the data in that project and import the section)
(these two things are... Too delicious. I feel I don't understand them at all. I feel that I need to learn them in the later stage)

Annotation related

When I configured annotations for various folders, I found that the annotation configured for the Mapper (dao) layer in my previous project was @ Repository. Now I configured @ Mapper for the Mapper (dao) layer, so I found relevant information on the Internet.

Add @ mapper or @ repository to the dao layer of mapper.

The difference between these two annotations is:

1,use@mapper After that, you don't need to spring Set the scanning address in the configuration through mapper.xml Inside namespace Attribute corresponds to the related mapper Class, spring Dynamic generation Bean After injection into ServiceImpl Yes.

2,@repository You need to Spring Configure scan package address in(@mapperscan)，Then generate dao Layered bean，Then injected into ServiceImpl in

Interaction between applet and backend

The description of this blog is quite good. There are descriptions for objects, arrays and common parameters
The @ RequestBody comment should be filled in at the back end,

The boolean value is found when passing the value. The passed value is always false

Solution

Boolean type, uppercase instead of lowercase

Boolean is a class, and Boolean is a basic data type. Boolean Defines an object and can be called as an object. Boolean Defines a data type and can only be called as a data type.

Modify the get and set methods of Boolean values
isAs => getAs

 1     private boolean as;
 2 
 3 
 4 //    public boolean isAs() {
 5 //        return as;
 6 //    }
 7 //
 8 //    public void setAs(boolean as) {
 9 //        this.as = as;
10 //    }
11 
12    //Modify to normal get and set
13     public boolean getAs() {
14         return as;
15     }
16 
17     public void setAs(boolean as) {
18         this.as = as;
19     }

An error occurred in the insert statement

Solution: one of my variables goes to the key from of sql, and there are always errors during operation,
Remember not to use sql keywords in sql statements

Let's stop here today... In fact, we haven't done anything at all. Tomorrow, we will add an additional field to the database user table, that is, the front end obtains the user name when the user logs in, or according to a unique information, I'm ready to use the name, and then send the user name to the session, so that we can share a user when signing in

Application of global variables of wechat applet

First define the global variables you want to use
Defined in app.js

  globalData: {
    userInfo: null,
    userNickName: null
  }

If this variable is used in the current app.js, then
this.globalData.userNickName

If you use this global variable in other js files,
const app = getApp()
app.globalData.userNickName

Realization of main function

The main function of my project is (mainly for airport and port managers) After an overseas person enters the house, after 14 days of isolation, I open the applet to sign in for 14 days. After he signs in, I will catch his location in the background, that is, for these high-risk groups, I will conduct a 14 day location monitoring. If a person makes a mistake, I will upload the person's track to the superior at the first time (there is a web terminal for managers)

Main code (disorderly copied)
In fact, the main functions are realized by the mutual use of the two methods
Use of setInterval method and clearinterval

In the wechat applet, I tested it with a real machine and found that the function can be realized on the client but not on the mobile phone. Originally, the url in wx.request should be changed to its own ip address, and then the mobile phone and computer should use the same network

summary

Finally, I encountered some problems... It blew up. I haven't written such bad code... Change it later?