The timing of the execution of the program

client --> Control layer --> The business layer --> The data layer --- Return relevant data layer by layer ---> The business layer --> Control layer --> client （ Render page , Present the results to the customer ）

Page submit request operation

To perform an add operation, you usually use post request
To perform an update operation, you usually use put request
To perform a get operation, you usually use get request
@RequestMapping It has multiple submission functions

Lombok

Lombok It's a third Java library , It's automatically inserted into the editor and build tool ,Lombok Provides a useful set of comments , It is used to tell the compiler tools in the compilation process , In the process of compiling source code into bytecode , Add some quantity template code to bytecode .

spring boot Hot deployment in Engineering

Definition ：
Spring Boot The developer is Spring Boot A hot deployment is provided in the project (spring-boot-devtools) modular , Support the hot deployment of the project ( After modifying some resources, there is no need to restart the service ), To improve development efficiency . The bottom layer is actually implemented with the help of two class loaders , A class loader does not load class, A class loader loading may change the class , To provide class hot deployment performance .
Expand learning content （ Hot replacement technology , Self learning through Baidu engine ）