IOC Vs DI Vs Factory Pattern

[Bhairava Surya]

Hi All,

I am new to Spring concepts. As I read IOC, I am confused what wrong with Factory Pattern that we are going for this IOC Pattern(hope this is also a pattern).

Please provide some basic examples for IOC/DI/Factory Pattern with their differences.

Thanks & Regards,
Ravi.

[Nathan Pruett]

Inversion of Control (IoC) and Dependency Injection (DI) usually refer to the same thing. IoC is a more general concept (instead of doing X itself, a class relies on some other class to do it) DI is IoC as applied to dependent classes (instead of creating a class that I depend on, it will be passed to me). DI is the most common use of IoC, so usually when they are discussed the terms are used interchangeably.

The Factory Pattern's main concern is creating things - DI's main concern is how things are connected together.

In practice, these two concerns (creating and connecting) are usually related, so most DI/IoC containers do both. You could think of most implementations as very configurable factories - but because the implementations address both concerns - not because the Factory pattern and DI/IoC are the same.

[Mark Spritzler]

And it isn't an OR thing. I can have Factories and still use IOC/DI

Mark