带有 ds 注释的一个目标服务的多个 PID

Question

我想知道是否可以利用声明性服务注释的 osgi 企业规范的 par.104.7.5（使用多位置）中解释的内容。引用规范：

It is also possible that Bundles are interested in multiple PIDs for one target service, for this reason they can register multiple PIDs for one service. [...]

A Bundle interested in the host configuration would register a Managed Service with the following properties:
service.pid = [ "com.acme.host", "com.acme.system" ]
The Bundle would be called back for both the com.acme.host and com.acme.system PID and must therefore discriminate between these two cases. This Managed Service therefore would have a callback like:

volatile URL url;
public void updated( Dictionary d ) {
if ( d.get("service.pid").equals("com.acme.host"))
    this.url = new URL( d.get("host"));
if ( d.get("service.pid").equals("com.acme.system"))
   ...
}

我尝试使用以下语法：

@Component(
    immediate = true,
    configurationPid = "[com.mycompany.ws.rest,com.mycompany.endpoints]",
    configurationPolicy = ConfigurationPolicy.REQUIRE
) 
public class TestImpl implements Test {
    // ...
}

但这失败了。当然，人们可以获得对配置管理员的引用并根据所需的 pid 浏览配置，但这对我来说似乎有点不雅，因为理论上可以将其委托给 ds 注释。

可能吗？正确的语法是什么？

谢谢！

Answer 1

我认为使用 configurationPid 和 configurationPolicy 值是不可能的。我所做的是：

将服务工厂 pid 定义为服务属性。
实现ManagedService接口。

示例：

@Component(property = {Constants.SERVICE_PID + "=com.acme.host", 
                       Constants.SERVICE_PID + "=com.acme.system"})
public class TestComponent implements ManagedService {

    @Override
    public void updated(Dictionary<String, ?> dict) {
    ...
    }

当然这有一个缺点，即即使没有配置你的组件也会被激活，但是你可以使用两个 PID。

Answer 2

即将推出的 DS 1.3 规范支持多个 PID。有关下载第 6 版规范草案的链接，请参阅 http://www.osgi.org/Specifications/Drafts。

Answer 3

较新的版本解决了这个问题...

发件人：https://osgi.org/specification/osgi.cmpn/7.0.0/service.component.html#org.osgi.service.component.annotations.Component

112.13.4.11 String[] configurationPid default "$" □ The configuration PIDs for the configuration of this Component.

Each value specifies a configuration PID for this Component.

If no value is specified, the name of this Component is used as the configuration PID of this Component.

A special string ("$") can be used to specify the name of the component as a configuration PID. The NAME constant holds this special string. For example:

@Component(configurationPid={"com.acme.system", Component.NAME}) Tools creating a Component Description from this annotation must replace the special string with the actual name of this Component.

See Also The configuration-pid attribute of the component element of a Component Description.

Since 1.2

带有 ds 注释的一个目标服务的多个 PID

Multiple PIDs for one target service with ds annotations

java

osgi

declarative-services