Spring

framework design concepts (Spring concepts)

• Inversion of Control (IoC)控制反转—Control of object creation is given to the framework (Spring)
• Dependency Injection (DI)依赖注入—A way to implement IoC
• AOP(Aspect-Oriented Programming)面向切片—Add extra behavior (like logging, transactions) without changing business code
• in Spring projects, you always see them together:

  @Service           // Bean (IoC) → manage objects
  @Autowired        // DI → inject dependencies
  @Transactional    // AOP → enhance behavior

what is a framework

• A framework is: A reusable structure that controls how your application runs
  • you write business code, framework controls execution.
• This is called Inversion of Control (IoC)
• Without framework:

  public static void main(String[] args) {
      // you create everything manually
  }

Spring — engine

• Spring = a large Java framework that provides core infrastructure for building applications
• It gives you fundamental capabilities:
  • IoC container (Bean management)
  • DI (dependency injection)
  • AOP (transactions, logging, etc.)
  • Spring MVC (web framework)
  • data access support (JDBC, ORM integration)
• But:
  • Configuration is complex
  • Need XML or lots of setup