Interface ConfigurationPlugin
A bundle registers a ConfigurationPlugin
object in order to
process configuration updates before they reach the Managed Service or
Managed Service Factory. The Configuration Admin service will detect
registrations of Configuration Plugin services and must call these services
every time before it calls the ManagedService
or
ManagedServiceFactory
updated
method. The
Configuration Plugin service thus has the opportunity to view and modify the
properties before they are passed to the Managed Service or Managed Service
Factory.
Configuration Plugin (plugin) services have full read/write access to all
configuration information. Therefore, bundles using this facility should be
trusted. Access to this facility should be limited with
ServicePermission[ConfigurationPlugin,REGISTER]
.
Implementations of a Configuration Plugin service should assure that they
only act on appropriate configurations.
The Integer
service.cmRanking
registration
property may be specified. Not specifying this registration property, or
setting it to something other than an Integer
, is the same as
setting it to the Integer
zero. The
service.cmRanking
property determines the order in which
plugins are invoked. Lower ranked plugins are called before higher ranked
ones. In the event of more than one plugin having the same value of
service.cmRanking
, then the Configuration Admin service
arbitrarily chooses the order in which they are called.
By convention, plugins with service.cmRanking< 0
or
service.cmRanking > 1000
should not make modifications to
the properties.
The Configuration Admin service has the right to hide properties from plugins, or to ignore some or all the changes that they make. This might be done for security reasons. Any such behavior is entirely implementation defined.
A plugin may optionally specify a cm.target
registration
property whose value is the PID of the Managed Service or Managed Service
Factory whose configuration updates the plugin is intended to intercept. The
plugin will then only be called with configuration updates that are targeted
at the Managed Service or Managed Service Factory with the specified PID.
Omitting the cm.target
registration property means that the
plugin is called for all configuration updates.
- Version:
- $Revision: 5673 $
-
Field Summary
Fields -
Method Summary
Modifier and TypeMethodDescriptionvoid
modifyConfiguration
(org.osgi.framework.ServiceReference reference, Dictionary properties) View and possibly modify the a set of configuration properties before they are sent to the Managed Service or the Managed Service Factory.
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Field Details
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CM_TARGET
A service property to limit the Managed Service or Managed Service Factory configuration dictionaries a Configuration Plugin service receives. This property contains aString[]
of PIDs. A Configuration Admin service must call a Configuration Plugin service only when this property is not set, or the target service's PID is listed in this property.- See Also:
-
CM_RANKING
A service property to specify the order in which plugins are invoked. This property contains anInteger
ranking of the plugin. Not specifying this registration property, or setting it to something other than anInteger
, is the same as setting it to theInteger
zero. This property determines the order in which plugins are invoked. Lower ranked plugins are called before higher ranked ones.- Since:
- 1.2
- See Also:
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Method Details
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modifyConfiguration
View and possibly modify the a set of configuration properties before they are sent to the Managed Service or the Managed Service Factory. The Configuration Plugin services are called in increasing order of theirservice.cmRanking
property. If this property is undefined or is a non-Integer
type, 0 is used.This method should not modify the properties unless the
service.cmRanking
of this plugin is in the range0 <= service.cmRanking <= 1000
.If this method throws any
Exception
, the Configuration Admin service must catch it and should log it.- Parameters:
reference
- reference to the Managed Service or Managed Service Factoryproperties
- The configuration properties. This argument must not contain the "service.bundleLocation" property. The value of this property may be obtained from theConfiguration.getBundleLocation
method.
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