OSGi声明式服务的绑定顺序 [英] Bind order of OSGi declarative services

问题描述

假设我使用OSGi声明式服务，并且我有一个服务，该服务的数字引用的策略为dynamic ...

Assuming I use OSGi Declarative Services and I have a service that have a number references with policy = dynamic...

A-强制性一元制。

B-强制一元。

C-强制倍数。

D-可选一元。

E-可选倍数。

在我的服务启动时，所有引用均可用。
有什么方法可以控制调用绑定的顺序吗？

All references are available when my service starts. Is there any way to control what order bind is called in?

我想让B首先绑定并对每个传入的E进行操作，但我无法确保B在E之前绑定。

I'd like to have B bind first and do something to each E that comes in, but I have no way of ensuring that B is bound before E.

是的，更合理的方法是让代表B的服务也绑定到E上，做它应该做的一切，但我不能修改B，只能使用它。如果我提供一个仅绑定到B和E的新服务，我仍然会遇到相同的问题。

Yes, the more logical approach would be to let the service that represents B also bind to E and do whatever it should do, but I can't modify B, I can only use it. If I make a new service that just binds to B and E I'll have the same problem still.

我可以在激活方法中做任何事情一切都绑定了，然后像附加的（动态）E绑定了一样，但是我想知道是否还有另一种方法...

I could do whatever I need to do in the activate method when everything is bound, and then do it as additional (dynamic) E's are bound, but I was wondering if there is another way...

推荐答案

使引用B使用静态策略，以确保在调用activate方法之前将其绑定。

Make reference B use the "static" policy, which ensures it will be bound before the activate method is invoked.

如果引用E被声明为Multiple / 动态策略是可选的-当您有多个引用时，这几乎是唯一合理的选择-然后，只要服务已发布/未发布，它将被绑定/取消绑定。这可以从任何线程发生，甚至可以在调用activate方法期间发生（多次！）。

If reference E is declared as multiple/optional with the "dynamic" policy -- which is pretty much the only reasonable choice when you have a multiple reference -- then it will be bound/unbound whenever the services are published/unpublished. This can happen from any thread, and can even happen (multiple times!) during the invocation of the activate method.

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