org.universAAL.middleware.container.osgi

Class OSGiContainer

java.lang.Object

org.universAAL.middleware.container.osgi.OSGiContainer

All Implemented Interfaces:

EventListener, org.osgi.framework.ServiceListener, Container

public final class OSGiContainer
extends Object
implements Container, org.osgi.framework.ServiceListener

An implementation of the concept of Container for OSGi.

Version:

$LastChangedRevision$ ( $LastChangedDate$ )

Author:

mtazari, Stefano Lenzi

Field Summary

Fields

Modifier and Type	Field and Description
static OSGiContainer	THE_CONTAINER

Method Summary

Modifier and Type	Method and Description
Object	fetchSharedObject(ModuleContext requester, Object[] fetchParams) Returns an object previously shared by another module for usage within this container.
Object[]	fetchSharedObject(ModuleContext requester, Object[] fetchParams, SharedObjectListener listener) Returns an object previously shared by another module for usage within this container.
ModuleContext	installModule(ModuleContext requester, Object[] installParams) Provides possibility for programmatically installing (downloaded) modules.
Iterator<LogListener>	logListeners() Returns an Iterator object over all registered instances of LogListener.
ModuleContext	registerModule(Object[] regParams) Provides possibility for wrapping container-specific context for a module in terms of an instance of the universAAL ModuleContext.
void	removeSharedObject(ModuleContext requester, Object objToRemove, Object[] shareParams) Removes an object previously shared by a module for usage within this container.
void	removeSharedObjectListener(SharedObjectListener listener) This method allows a SharedObjectListener instance to be removed from the list of listeners managed by this container
void	serviceChanged(org.osgi.framework.ServiceEvent se)
void	shareObject(ModuleContext requester, Object objToShare, Object[] shareParams) Makes a given object accessible for the other modules hosted by this container.

Methods inherited from class java.lang.Object

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

Field Detail

THE_CONTAINER

public static final OSGiContainer THE_CONTAINER

Method Detail

fetchSharedObject

public Object fetchSharedObject(ModuleContext requester,
                                Object[] fetchParams)

Description copied from interface: Container

Returns an object previously shared by another module for usage within this container.

Specified by:

fetchSharedObject in interface Container

Parameters:

fetchParams -

• min length = 1, max used length is 2 (elements @ index 2+ are ignored)
• type of both elements must be String
• if element @ index 0 is null, there must be a not-null String object @ index 1
• if length = 1, then element @ index 0 must be not-null
• if length = 1, then BundleContext.getServiceReference(String) will be used to fetch a service object
• if length > 1, then BundleContext.getServiceReferences(String, String) will be used to fetch the first service object from the returned array

requester - The module in the context of which the shared object is going to be used.

Returns:

if the given requester is an instance of OSGiModuleContext and a ServiceReference has been found according to the explanations given for fetchParams, then the result of calling BundleContext.getService(ServiceReference) will be returned.

See Also:

Container.fetchSharedObject(ModuleContext, Object[], SharedObjectListener)

fetchSharedObject

public Object[] fetchSharedObject(ModuleContext requester,
                                  Object[] fetchParams,
                                  SharedObjectListener listener)

Description copied from interface: Container

Returns an object previously shared by another module for usage within this container.

Specified by:

fetchSharedObject in interface Container

Parameters:

requester - The module in the context of which the shared object is going to be used.

fetchParams - Container-specific parameters for fetching shared objects.

listener - If not null, the listener will be notified asynchronously each time a new matching object is shared within this container.

installModule

public ModuleContext installModule(ModuleContext requester,
                                   Object[] installParams)

Description copied from interface: Container

Provides possibility for programmatically installing (downloaded) modules.

Specified by:

installModule in interface Container

Parameters:

installParams -

• min length = 1, max used length is 2 (elements @ index 2+ are ignored)
• type of element @ index 0 must be String (mandatory)
• if existing, type of element @ index 1 must be InputStream
• if length = 1, then BundleContext.installBundle(String) will be used to install the given bundle
• if length > 1, then BundleContext.installBundle(String, java.io.InputStream) will be used to install the given bundle

requester - The module requesting the installation; only an certain modules should be allowed to install modules on the fly

Returns:

a newly created instance of OSGiModuleContext that wraps the newly installed bundle if the given requester is an instance of OSGiModuleContext, the conditions on installParams hold, and the installation is successful, null otherwise.

See Also:

Container.installModule(org.universAAL.middleware.container.ModuleContext, java.lang.Object[])

logListeners

public Iterator<LogListener> logListeners()

Description copied from interface: Container

Returns an Iterator object over all registered instances of LogListener.

Specified by:

logListeners in interface Container

See Also:

Container.logListeners()

registerModule

public ModuleContext registerModule(Object[] regParams)

Description copied from interface: Container

Provides possibility for wrapping container-specific context for a module in terms of an instance of the universAAL ModuleContext.

Specified by:

registerModule in interface Container

Parameters:

regParams - element @ index 0 must exist and be an instance of BundleContext

Returns:

an instance of OSGiModuleContext if the conditions for regParams hold, null otherwise

See Also:

Container.registerModule(java.lang.Object[])

serviceChanged

public void serviceChanged(org.osgi.framework.ServiceEvent se)

Specified by:

serviceChanged in interface org.osgi.framework.ServiceListener

See Also:

ServiceListener.serviceChanged(org.osgi.framework.ServiceEvent)

shareObject

public void shareObject(ModuleContext requester,
                        Object objToShare,
                        Object[] shareParams)

Description copied from interface: Container

Makes a given object accessible for the other modules hosted by this container.

Specified by:

shareObject in interface Container

Parameters:

shareParams -

• min length = 1, no upper limit
• all elements (except for an optional last one - see next bullet) must be instances of String; these strings specify the interfaces that the objToShare has implemented (cf. BundleContext.registerService(String[], Object, java.util.Dictionary) ).
• optionally, a last element can be an instance of Dictionary; it can be used for property-based search of shared objects (cf. BundleContext.registerService(String[], Object, java.util.Dictionary) ).

requester - The module in the context of which the shared object is going to be used.

objToShare - The actual object to be shared.

See Also:

Container.shareObject(org.universAAL.middleware.container.ModuleContext, java.lang.Object, java.lang.Object[])

removeSharedObject

public void removeSharedObject(ModuleContext requester,
                               Object objToRemove,
                               Object[] shareParams)

Description copied from interface: Container

Removes an object previously shared by a module for usage within this container.

Specified by:

removeSharedObject in interface Container

Parameters:

requester - The module in the context of which the shared object was shared.

removeSharedObjectListener

public void removeSharedObjectListener(SharedObjectListener listener)

Description copied from interface: Container

This method allows a SharedObjectListener instance to be removed from the list of listeners managed by this container

Specified by:

removeSharedObjectListener in interface Container

Parameters:

listener - the SharedObjectListener to be removed