Internship log - day07

spring framework Frame diagram

Spring What is it? ？ First of all, it is an open source project , And very active ; It is based on IOC and AOP It's multi-layered j2ee The framework of the system , But it doesn't force you to have to use in every layer Spring, Because it's modular , It allows you to choose one of its modules according to your own needs ; It achieves a very elegant MVC, It provides a unified interface for different data access technologies , use IOC Make it easy to implement bean The assembly of , Provides a concise AOP And based on it Transaction Management

spel :spring express languge,spring Expression language
AOP： Tangent oriented programming
aspect： aspect , level , Looks like , appearance
instrutation： Method
ORM: Object relation mapping （Object Relational Mapping, abbreviation ORM）, In fact, it is to convert the data into another form

1、IOC
inversion of control—— Inversion of control （ One of the core ）
The operation of acquiring objects in a passive way

2、DI:dependency Injection Dependency injection
Use bean Tags create objects , Put data in it
getbean from spring Get an object in the container , Not creating objects

3、 Used in labels 102 The configuration order needs to match the formal parameter list in the corresponding method