org.opencastproject.util.osgi

Class SimpleServicePublisher

java.lang.Object

org.opencastproject.util.osgi.SimpleServicePublisher

All Implemented Interfaces:

org.osgi.service.cm.ManagedService

public abstract class SimpleServicePublisher
extends Object
implements org.osgi.service.cm.ManagedService

An implementation of SimpleServicePublisher creates and registers another service with the OSGi environment.

Using this class helps to decouple business logic from the OSGi environment. The business class can be kept clean from any OSGi specific needs like dependency setters, activate/deactivate methods or the implementation of OSGi related interfaces like ManagedService to receive configuration data. This makes the business logic far easier to test and results in a mucher cleaner design.

Another approach to decouple the service logic from the OSGi environment is to create an abstract service class which declares all it's dependencies as abstract getter methods. The OSGi connection is then implemented in an inheriting class. This method, however, has the drawback of having to renounce a constructor implementation since no dependencies have been set yet.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SimpleServicePublisher.ServiceReg

Constructor Summary

Constructors

Constructor and Description
SimpleServicePublisher()

Method Summary

Modifier and Type	Method and Description
void	activate(org.osgi.service.component.ComponentContext cc) OSGi callback.
static Effect0	close(Closeable c) Create an effect to close a closeable suitable to return by registerService(java.util.Dictionary, org.osgi.service.component.ComponentContext).
static Effect0	close(PersistenceEnv penv) Create an effect to close a persistence environment suitable to return by registerService(java.util.Dictionary, org.osgi.service.component.ComponentContext).
void	deactivate() OSGi callback.
abstract boolean	needConfig() Return false if the service to be registered does not need a configuration dictionary provided by the ConfigAdmin.
static org.osgi.framework.ServiceRegistration	registerService(org.osgi.service.component.ComponentContext cc, Object o, Class serviceClass, String serviceDescription) Register a service with the OSGi environment in a standardized way.
abstract SimpleServicePublisher.ServiceReg	registerService(Dictionary properties, org.osgi.service.component.ComponentContext cc) Create and register a service object.
static Effect0	unregisterService(org.osgi.framework.ServiceRegistration sr) Create an effect to unregister a service suitable to return by registerService(java.util.Dictionary, org.osgi.service.component.ComponentContext).
void	updated(Dictionary properties)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SimpleServicePublisher

public SimpleServicePublisher()

Method Detail

registerService

public abstract SimpleServicePublisher.ServiceReg registerService(Dictionary properties,
                                                                  org.osgi.service.component.ComponentContext cc)
                                                           throws org.osgi.service.cm.ConfigurationException

Create and register a service object. Register with the OSGi environment using registerService(org.osgi.service.component.ComponentContext, Object, Class, String) or cc.getBundleContext().registerService(..).

Parameters:

properties - a configuration object received by the ManagedService.updated(java.util.Dictionary) callback, never null

Returns:

a structure of registered services and a list of (optional) effects to run on service shutdown

Throws:

org.osgi.service.cm.ConfigurationException

needConfig

public abstract boolean needConfig()

Return false if the service to be registered does not need a configuration dictionary provided by the ConfigAdmin.

activate

public void activate(org.osgi.service.component.ComponentContext cc)
              throws org.osgi.service.cm.ConfigurationException

OSGi callback.

Throws:

org.osgi.service.cm.ConfigurationException

deactivate

public void deactivate()

OSGi callback.

updated

public void updated(Dictionary properties)
             throws org.osgi.service.cm.ConfigurationException

Specified by:

updated in interface org.osgi.service.cm.ManagedService

Throws:

org.osgi.service.cm.ConfigurationException

registerService

public static org.osgi.framework.ServiceRegistration registerService(org.osgi.service.component.ComponentContext cc,
                                                                     Object o,
                                                                     Class serviceClass,
                                                                     String serviceDescription)

Register a service with the OSGi environment in a standardized way. The service properties Constants.SERVICE_PID and Constants.SERVICE_DESCRIPTION are created properly.

unregisterService

public static Effect0 unregisterService(org.osgi.framework.ServiceRegistration sr)

Create an effect to unregister a service suitable to return by registerService(java.util.Dictionary, org.osgi.service.component.ComponentContext).

close

public static Effect0 close(Closeable c)

Create an effect to close a closeable suitable to return by registerService(java.util.Dictionary, org.osgi.service.component.ComponentContext).

close

public static Effect0 close(PersistenceEnv penv)

Create an effect to close a persistence environment suitable to return by registerService(java.util.Dictionary, org.osgi.service.component.ComponentContext).