Spring Framework & Inversion of Control

By Nazim Sitmanbetov

Preconditions Keep calm Sit back Relax

Inversion of Control OOP principle, not design pattern One of

Principle in OOP Modules depend on abstractions Low level modules do not depend on

high level modules

Modules depend on abstractions

Bad Good

Low level modules do not depend on high level modules

Bad Good

Tip: Avoid cyclic dependencies

IoC implementations Factory Method Service Locator Dependency Injection (DI)

Factory Method

Service Locator

Dependency Injection Allow client of module to set

dependencyModule Client

Achievement unlocked

Framework

Java Light-weight Open Source

What means Light-Weight? No container requirements Quick start Application easy-to-test

Spring & IoC Dependency Injection Service Locator

Spring & Dependency InjectionXML Based Configurationmcdonalds-with-kazatin.xml

Java Program

Spring & Service LocatorAnnotation Basedmcdonalds-locator.xml

Spring & Service Locator

Dependency Injection vs Service Locator

DI Service Locator

• Imperative• Can be used with

existing classes

• Declarative• Need to modify

existing classes

Spring components

Time to cook