Inversion of Control Inversion of Control (IoC) is the reversal of responsibility with regard to how an object obtains references to other objects. Normally, each object is responsible for obtaining its own references to its dependencies. With IoC, objects are given their dependencies at creation time by an external entity which handles all the objects in the system.Dependency Injection
Dependency Injection is merely a more apt name for IoC, given that dependencies are injected into objects. There are 3 types of IoC:
1) Interface Dependent - Dependencies are managed by implementing special interfaces.
2) Setter Injection - Dependencies and properties are configured via the setter methods.
3) Constructor Injection - Dependencies and properties are configured via the constructor.
IoC allow the Java objects to be loosely coupled, interacting through interfaces. It allows the programmer to set up and configure the objects as desired, while leaving little trace of it in the code itself.
Application design for Spring would be based on interfaces. Overall, the code would be normal POJO, until arriving at the Spring setup; a class using all the objects coded and a Spring configuration file, usually XML.
2) Setter Injection - Dependencies and properties are configured via the setter methods.
3) Constructor Injection - Dependencies and properties are configured via the constructor.
IoC allow the Java objects to be loosely coupled, interacting through interfaces. It allows the programmer to set up and configure the objects as desired, while leaving little trace of it in the code itself.
Application design for Spring would be based on interfaces. Overall, the code would be normal POJO, until arriving at the Spring setup; a class using all the objects coded and a Spring configuration file, usually XML.
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