Spring-如何避免实现在协作服务之间锁定

Question

I am writing a small framework which uses spring for DI. I have a number of services which collaborate with each other.

ServiceA has reference to ServiceB - has reference to ServiceC etc. All these are prewired in spring configuration xml.

The issue occurs when the user tries to override one of these implementations, say ServiceB with his own, say ChildServiceB. Now, what I really want here is that the users ChildSerivceB should be wired into ServiceA. Can it be done in spring? If not, what is the best design pattern for this scenario?

Something like a late-binding for spring is what I am looking for.

I would like the user's spring configuration needs to be as minimal as possible in such scenarios.

Other Notes:

I use interfaces for all my services

To make it easy for people who use the default services, the spring congiuration framework-beans.xml is provided in the jar, they just need to instantiate it.

Users who want to override implementations can create their own beans.xml, but that is where I am stumped, how do they override the "wiring" of framework-beans.xml?

Answer 1

The issue occurs when the user tries to override one of these implementations, say ServiceB with his own, say ChildServiceB. Now, what I really want here is that the users ChildSerivceB should be wired into ServiceA. Can it be done in spring? If not, what is the best design pattern for this scenario?

1 Use Interface programming
2 Let user implement its own Service for ServiceB
3 Configure Bean in Spring xml

<bean name="serviceB" class="com.something.DefaultServiceBImpl"/>

now if you want user to have its own implementation just change it to

<bean name="serviceB" class="com.something.CustomServiceBImpl"/>

and in Class use interface