org.osgi.service.cm.ManagedServiceFactory Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2001, 2008). All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.osgi.service.cm;
import java.util.Dictionary;
/**
* Manage multiple service instances.
*
* Bundles registering this interface are giving the Configuration Admin service
* the ability to create and configure a number of instances of a service that
* the implementing bundle can provide. For example, a bundle implementing a
* DHCP server could be instantiated multiple times for different interfaces
* using a factory.
*
*
* Each of these service instances is represented, in the persistent
* storage of the Configuration Admin service, by a factory
* Configuration object that has a PID. When such a
* Configuration is updated, the Configuration Admin service
* calls the ManagedServiceFactory updated method with the new
* properties. When updated is called with a new PID, the Managed
* Service Factory should create a new factory instance based on these
* configuration properties. When called with a PID that it has seen before, it
* should update that existing service instance with the new configuration
* information.
*
*
* In general it is expected that the implementation of this interface will
* maintain a data structure that maps PIDs to the factory instances that it has
* created. The semantics of a factory instance are defined by the Managed
* Service Factory. However, if the factory instance is registered as a service
* object with the service registry, its PID should match the PID of the
* corresponding Configuration object (but it should not
* be registered as a Managed Service!).
*
*
* An example that demonstrates the use of a factory. It will create serial
* ports under command of the Configuration Admin service.
*
*
*
* class SerialPortFactory
* implements ManagedServiceFactory {
* ServiceRegistration registration;
* Hashtable ports;
* void start(BundleContext context) {
* Hashtable properties = new Hashtable();
* properties.put( Constants.SERVICE_PID,
* "com.acme.serialportfactory" );
* registration = context.registerService(
* ManagedServiceFactory.class.getName(),
* this,
* properties
* );
* }
* public void updated( String pid,
* Dictionary properties ) {
* String portName = (String) properties.get("port");
* SerialPortService port =
* (SerialPort) ports.get( pid );
* if ( port == null ) {
* port = new SerialPortService();
* ports.put( pid, port );
* port.open();
* }
* if ( port.getPortName().equals(portName) )
* return;
* port.setPortName( portName );
* }
* public void deleted( String pid ) {
* SerialPortService port =
* (SerialPort) ports.get( pid );
* port.close();
* ports.remove( pid );
* }
* ...
* }
*
*
*
* @version $Revision: 5673 $
*/
public interface ManagedServiceFactory {
/**
* Return a descriptive name of this factory.
*
* @return the name for the factory, which might be localized
*/
public String getName();
/**
* Create a new instance, or update the configuration of an existing
* instance.
*
* If the PID of the Configuration object is new for the
* Managed Service Factory, then create a new factory instance, using the
* configuration properties provided. Else, update the
* service instance with the provided properties.
*
*
* If the factory instance is registered with the Framework, then the
* configuration properties should be copied to its registry
* properties. This is not mandatory and security sensitive properties
* should obviously not be copied.
*
*
* If this method throws any Exception, the Configuration
* Admin service must catch it and should log it.
*
*
* When the implementation of updated detects any kind of error in the
* configuration properties, it should create a new
* {@link ConfigurationException} which describes the problem.
*
*
* The Configuration Admin service must call this method asynchronously.
* This implies that implementors of the ManagedServiceFactory
* class can be assured that the callback will not take place during
* registration when they execute the registration in a synchronized method.
*
* @param pid The PID for this configuration.
* @param properties A copy of the configuration properties. This argument
* must not contain the service.bundleLocation" property. The value
* of this property may be obtained from the
* Configuration.getBundleLocation method.
* @throws ConfigurationException when the configuration properties are
* invalid.
*/
public void updated(String pid, Dictionary properties)
throws ConfigurationException;
/**
* Remove a factory instance.
*
* Remove the factory instance associated with the PID. If the instance was
* registered with the service registry, it should be unregistered.
*
* If this method throws any Exception, the Configuration
* Admin service must catch it and should log it.
*
* The Configuration Admin service must call this method asynchronously.
*
* @param pid the PID of the service to be removed
*/
public void deleted(String pid);
}