IOC / Dependency injection:-
Dependency lookup:-
In this process resource spends rimes to search & gather its dependent values from other resource of the application. In this process the resource pulls the values from other resources.
Example: – The way JDBC data source object is gathered from registry software through JNDI comes under dependency lookup.
Example: – If student gets its course material from institute staff only by asking / demanding for it comes under dependency lookup.
Dependency injection:-
- If the underlying s/w or framework or container or server or special resource of the application is assigning values to our resource dynamically or automatically then that process is called as “Dependency Injection”.
- In this process the underlying s/w processes values to the resource.
Real life example: – The way institute staff person assigns material to students immediately after is registration for course comes under dependency injection.
Technical example: – The way ActionServlet writes form data of form page to form bean class object dynamically comes under dependency injection.
MVC2 in Struts:-
- This design pattern allows the programmer to develop the web application by having multiple layers & clean separation of logics.
- Struts application also contains multiple layers like view controller & model and also allows clean separation of logics.