Spring Technical Manual Reading Notes

1. dependency Injection (Dependency Injection) is an abstract interface that allows components to depend on abstract interfaces. When a component needs to be dependent on other actual objects, abstract interfaces are used to inject dependent objects. There are three basic implementation methods for dependency injection: Interface injection, setter injection, and construction injection. They are called Type 1 IoC, Type 2 IoC, and Type 3 IoC respectively .. Spring encourages setter injection, but Construction injection is also allowed.