alma.acs.container

Interface ContainerServices

All Superinterfaces:

ContainerServicesBase

All Known Implementing Classes:

ContainerServicesImpl, ContainerServicesProxy, DummyContainerServices

public interface ContainerServices
extends ContainerServicesBase

Through this interface, the container offers services to its hosted components. The component must call these methods explicitly; in this respect, ContainerServices is different from the other services that the container provides without the component implementation knowing about it. It can be thought of as a callback handle or a library.

Currently, methods are added to this interface as the functionality becomes available. At some point we will have to declutter the interface by introducing 2nd-level interfaces that harbor cohesive functionality. For example, instead of calling myContainerServices.getComponent(...), the new call will then be something like myContainerServices.communication().getComponent(...).

created on Oct 24, 2002 12:56:36 PM

Author:

hsommer

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	ContainerServices.ComponentListener
static class	ContainerServices.ComponentReleaseCallback Callback that can be optionally given to releaseComponent(String, ComponentReleaseCallback).
static class	ContainerServices.ComponentReleaseCallbackWithLogging Variant of ContainerServices.ComponentReleaseCallback which logs all errors.

Method Summary

Modifier and Type	Method and Description
<T extends OffShootOperations> OffShoot	activateOffShoot(T offshootImpl, java.lang.Class<T> idlOpInterface) Activates an Object as an OffShoot.
void	assignUniqueEntityId(EntityT entity) Creates a unique id and sets it on the given (binding class) entity object.
java.lang.String[]	findComponents(java.lang.String curlWildcard, java.lang.String typeWildcard) Finds components by their instance name (curl) and/or by their type.
AlarmSource	getAlarmSource() Returns the AlarmSource owned by this object.
org.omg.CORBA.Object	getCollocatedComponent(ComponentQueryDescriptor compSpec, boolean markAsDefaul, java.lang.String targetCompUrl) Dynamic version of getCollocatedComponent(String, String).
org.omg.CORBA.Object	getCollocatedComponent(java.lang.String compUrl, java.lang.String targetCompUrl) Gets a component that will run collocated with a given component.
org.omg.CORBA.Object	getComponent(java.lang.String componentUrl) Gets a component specified by its instance name.
ComponentDescriptor	getComponentDescriptor(java.lang.String componentUrl) Gets the component descriptor which contains meta data for the component.
org.omg.CORBA.Object	getComponentNonSticky(java.lang.String curl) Gets a non-sticky reference to a component.
ComponentStateManager	getComponentStateManager() Delivers the ComponentStateManager object through which the component and the container administrate the state of the component.
org.omg.CORBA.Object	getDefaultComponent(java.lang.String componentIDLType) Gets the default component specified by the component type.
org.omg.CORBA.Object	getDynamicComponent(ComponentQueryDescriptor compSpec, boolean markAsDefault) Gets a component whose instance is not registered in the CDB at deployment time.
org.omg.CORBA.Object	getDynamicComponent(ComponentSpec compSpec, boolean markAsDefault) Deprecated. use getDynamicComponent(ComponentQueryDescriptor, boolean) instead. if you need to set not only the standard fields component_name or component_type, but also the more advanced values component_code or container_name, please send a request to ACS so that access to these fields be included in the ComponentQueryDescriptor given to the recommended version of this method.
org.omg.CORBA.Object	getReferenceWithCustomClientSideTimeout(org.omg.CORBA.Object originalCorbaRef, double timeoutSeconds) Wraps a component reference (or offshoot reference etc) such that the given timeout is applied on the client side of calls to this (possibly remote) object.
<T,F> T	getTransparentXmlWrapper(java.lang.Class<T> transparentXmlIF, F objectReference, java.lang.Class<F> flatXmlIF) Converts a "flat-XML" remote object (RO) interface (as obtained from the various getComponent methods, in the case of components, or by retrieving offshoots from components, in the case of offshoots) to a "transparent-XML" RO interface.
void	registerComponentListener(ContainerServices.ComponentListener listener) Allows a client to register a callback object that gets notified when some component(s) in use by the client (= components the client requested previously) dies or comes back to life (with ComponentListener#includeForeignComponents()==false).
void	releaseComponent(java.lang.String componentUrl) Releases the specified component.
void	releaseComponent(java.lang.String componentUrl, ContainerServices.ComponentReleaseCallback callback) Releases the reference to the specified component.

Methods inherited from interface alma.acs.container.ContainerServicesBase

activateOffShoot, createNotificationChannelPublisher, createNotificationChannelPublisher, createNotificationChannelSubscriber, createNotificationChannelSubscriber, deactivateOffShoot, getAdvancedContainerServices, getCDB, getLogger, getName, getThreadFactory

Method Detail

getComponentStateManager

ComponentStateManager getComponentStateManager()

Delivers the ComponentStateManager object through which the component and the container administrate the state of the component.

The component needs to access the ComponentStateManager if it wishes to change its state. If it doesn't, only the container will change the state based on the information it has available.

Returns:

the state manager

See Also:

alma.ACS.ComponentStates

getComponent

org.omg.CORBA.Object getComponent(java.lang.String componentUrl)
                           throws AcsJContainerServicesEx

Gets a component specified by its instance name. Delegates to get_component.

• This method is necessarily generic and will require a cast to the requested interface, like in HelloComponent helloComp = HelloComponentHelper.narrow(containerServices.getComponent("HELLOCOMP1"));.
• the more general method get_service offered by the manager is deliberately not represented here. It would currently (Oct.03) offer access to "LogFactory", "NotifyEventChannelFactory", "ArchivingChannel@ARCHIVING.channels", "LoggingChannel", "InterfaceRepository", "CDB", "ACSLogSvc"; It seems that if such access is needed, specialized methods should be added to this interface, like ContainerServicesBase.getCDB().
• if requested, we may come up with some additional way (e.g. a code-generated singleton class) to give type safe access to other components, like done with EJB xxxHome.
• the Container will later shortcut calls for components inside the same process. Like in EJB and CORBA, the implementation must therefore not assume receiving a by-value copy of any parameter from the other component.

Parameters:

componentUrl - the ACS CURL of the deployed component instance.

Returns:

the CORBA proxy for the component.

Throws:

AcsJContainerServicesEx - if something goes wrong.

getComponentNonSticky

org.omg.CORBA.Object getComponentNonSticky(java.lang.String curl)
                                    throws AcsJContainerServicesEx

Gets a non-sticky reference to a component. This is typically used by "weak clients" such as graphical user interfaces that only want to observe the running system without interfering with its functioning.

A non-sticky reference does not bind the Manager to keep alive the Component, and the Client requesting a non-sticky reference is not considered when checking for reference counts. The non-sticky reference should not be released, as that call will fail. The Manager can deactivate Components independently of any non-sticky reference. Since a non-sticky reference is not considered in reference counting, it will also not activate the component if it is not already active. As a consequence, asking for a non-sticky reference to a not-active Component throws an exception. The client represented by id (the handle) must have adequate access rights to access the component.

Parameters:

curl - the component URL (component instance name)

Returns:

the CORBA proxy for the component.

Throws:

AcsJContainerServicesEx - if something goes wrong

Since:

ACS 6.0

getDefaultComponent

org.omg.CORBA.Object getDefaultComponent(java.lang.String componentIDLType)
                                  throws AcsJContainerServicesEx

Gets the default component specified by the component type. The type is the IDL type, such as IDL:alma/PS/PowerSupply:1.0.

A default instance for the given type must have been declared beforehand (either statically in the CDB config files, or dynamically), otherwise an exception is thrown.

To get more information on the returned component, call getComponentDescriptor(java.lang.String) with the instance name that you can get from the component using alma.ACS.ACSComponentOperations#name.

Delegates to si.ijs.maci.ManagerOperations#get_default_component.

Parameters:

componentIDLType -

Returns:

Throws:

AcsJContainerServicesEx

getCollocatedComponent

org.omg.CORBA.Object getCollocatedComponent(java.lang.String compUrl,
                                            java.lang.String targetCompUrl)
                                     throws AcsJContainerServicesEx

Gets a component that will run collocated with a given component.

Parameters:

compUrl - the component's name (URL)

targetCompUrl - the name (URL) of the target component, in whose container we also want compUrl to run.

Returns:

the component reference, which should be cast using the appropriate CORBA narrow operation. Never null.

Throws:

AcsJContainerServicesEx - If the call failed and no component reference could be obtained.

Since:

ACS 5.0.3

getCollocatedComponent

org.omg.CORBA.Object getCollocatedComponent(ComponentQueryDescriptor compSpec,
                                            boolean markAsDefaul,
                                            java.lang.String targetCompUrl)
                                     throws AcsJContainerServicesEx

Dynamic version of getCollocatedComponent(String, String).

Parameters:

compSpec - the description of the component to be created

markAsDefaul - if true, the new component will become the default component for its IDL type.

targetCompUrl - targetCompUrl the name (URL) of the target component, in whose container we also want compUrl to run.

Returns:

Throws:

AcsJContainerServicesEx - If the call failed and no component reference could be obtained.

Since:

ACS 6.0.4

getDynamicComponent

org.omg.CORBA.Object getDynamicComponent(ComponentQueryDescriptor compSpec,
                                         boolean markAsDefault)
                                  throws AcsJContainerServicesEx

Gets a component whose instance is not registered in the CDB at deployment time.

The fields of compSpec can be filled in at various levels of detail, allowing the manager to blend in missing data from static deployment information. For a detailed description of the various options, please refer to the ACS documentation.

To get more information on the returned component, call getComponentDescriptor(java.lang.String) with the instance name that you've specified or that you can get from the component in case it was assigned (see alma.ACS.ACSComponentOperations#name()).

Delegates to si.ijs.maci.ManagerOperations#get_dynamic_component.

Parameters:

compSpec - the description of the component to be created

markAsDefault - if true, the new component will become the default component for its IDL type.

Throws:

AcsJContainerServicesEx

getDynamicComponent

org.omg.CORBA.Object getDynamicComponent(ComponentSpec compSpec,
                                         boolean markAsDefault)
                                  throws AcsJContainerServicesEx

Deprecated. use getDynamicComponent(ComponentQueryDescriptor, boolean) instead. if you need to set not only the standard fields component_name or component_type, but also the more advanced values component_code or container_name, please send a request to ACS so that access to these fields be included in the ComponentQueryDescriptor given to the recommended version of this method.

More powerful and thus more dangerous version of getDynamicComponent(ComponentQueryDescriptor, boolean) which exposes a CORBA struct directly.

Parameters:

compSpec - the description of the component to be created

markAsDefault - if true, the new component will become the default component for its IDL type.

Throws:

AcsJContainerServicesEx

findComponents

java.lang.String[] findComponents(java.lang.String curlWildcard,
                                  java.lang.String typeWildcard)
                           throws AcsJContainerServicesEx

Finds components by their instance name (curl) and/or by their type. Wildcards can be used for the curl and type. This method returns a possibly empty array of component curls; for each curl, you may then call getComponent to obtain the reference.

Parameters:

curlWildcard - (null is understood as "*")

typeWildcard - (null is understood as "*")

Returns:

the curls of the component(s) that match the search.

Throws:

AcsJContainerServicesEx

See Also:

si.ijs.maci.ManagerOperations#get_component_info(int, int[], java.lang.String, java.lang.String, boolean)

getComponentDescriptor

ComponentDescriptor getComponentDescriptor(java.lang.String componentUrl)
                                    throws AcsJContainerServicesEx

Gets the component descriptor which contains meta data for the component. (Not to be confused with a component descriptor in the EJB sense.)

To be used primarily after retrieval of a component with getDefaultComponent or getDynamicComponent, when some data like the instance name is not known. The idea behind having this method separately is that in many cases, components are not interested in this information, and are happier to get back from these methods directly the remote reference to another component, instead of always dealing with a ComponentDescriptor.

Parameters:

componentUrl - the unique name of a component

Returns:

the descriptor from which the various data items can be obtained.

Throws:

ContainerException - if componentUrl is unknown or anything else goes wrong

AcsJContainerServicesEx

See Also:

si.ijs.maci.ComponentInfo

releaseComponent

void releaseComponent(java.lang.String componentUrl)

Releases the specified component. This involves notification of the manager, as well as calling _release() on the CORBA stub for that component. If the curl is not known to the container, the request will be ignored.

This method will return only when the component has actually been released, which may take some time in case there are still active requests being processed.

This method is kept for convenience, providing a specific subset of the functionality that the more flexible releaseComponent(String, ComponentReleaseCallback) offers. It blocks the client until the component is released or a timeout of 60 seconds has occurred, and logs all errors of component release at level DEBUG.

Parameters:

componentUrl - the name/curl of the component instance as used by the manager

releaseComponent

void releaseComponent(java.lang.String componentUrl,
                      ContainerServices.ComponentReleaseCallback callback)

Releases the reference to the specified component. Releasing a component reference may result in the deactivation of that component, if no other clients hold (sticky) references.

This call will return as soon as the release request has been delivered to the ACS manager, which means that the reference count evaluation and possible component deactivation will happen only after returning from this call.

If your code must synchronize with the reference evaluation and possible component deactivation in the target container, or if you are interested in exceptions that may occur during component deactivation, then you should supply the optional ComponentRequestCallback object and block execution of your calling thread until you receive the callback.

If an exception (such as no-permission) is thrown during the synchronous first part of the underlying call to the manager, then this exception will not be thrown upward by this method but will instead be reported to the optional callback object, just like any exception that happens later during the asynchronous part of the component release. The idea here is to have either "interested" clients that want to get all exceptions, or "easy" clients that do not care about any exceptions, thus do not provide a callback object, and also do not want to bother about a try/catch block.

Parameters:

componentUrl - the name/curl of the component instance as used by the manager

callback - may be null if you do not need to wait for component deactivation or to see the results. An new instance of ComponentReleaseCallback is required for every call.

Since:

ACS 9.1

registerComponentListener

void registerComponentListener(ContainerServices.ComponentListener listener)

Allows a client to register a callback object that gets notified when some component(s) in use by the client (= components the client requested previously) dies or comes back to life (with ComponentListener#includeForeignComponents()==false).

If the client wants to get notified even for components that it does not hold a reference to, then ComponentListener#includeForeignComponents() should return true; notification about components that this client does not use may be limited though, e.g. to components collocated in the same container.

Parameters:

listener -

Since:

ACS 6.0

See Also:

si.ijs.maci.ClientOperations#components_available(si.ijs.maci.ComponentInfo[])

getReferenceWithCustomClientSideTimeout

org.omg.CORBA.Object getReferenceWithCustomClientSideTimeout(org.omg.CORBA.Object originalCorbaRef,
                                                             double timeoutSeconds)
                                                      throws AcsJContainerServicesEx

Wraps a component reference (or offshoot reference etc) such that the given timeout is applied on the client side of calls to this (possibly remote) object. If the total call, including de-/serialization and network travel, takes longer than the given timeout, an org.omg.CORBA.TIMEOUT exception will be thrown.

This allows us to override the general timeout given at the system level (e.g. orb.properties file in case of jacorb) and the container-level timeout given in the CDB container configuration. It is possible to set the timeout to values that are shorter or longer than the default timeout. You should chose a timeout value that matches the expected response time, with a large safety margin of

Note that calls to which the specified timeout should apply must be made on the object reference returned from this method, and not on the original object that gets passed to this method! Some corba implementations may apply the timeout to both objects though, or return the original object.

Parameters:

corbaRef - Reference to a component or an offshoot as obtained from some of the other container services methods.

timeoutSeconds - the custom client side timeout in seconds, to be used for all calls to the given object reference.

Returns:

A new object reference which should be used to make calls with the specified timeout applied.

Throws:

AcsJContainerServicesEx

assignUniqueEntityId

void assignUniqueEntityId(EntityT entity)
                   throws AcsJContainerServicesEx

Creates a unique id and sets it on the given (binding class) entity object. The id will be redundantly stored in an encrypted format so that later it can be verified that the id is indeed the one originally assigned.

Parameters:

entity - must be freshly created and

Throws:

AcsJContainerServicesEx

getTransparentXmlWrapper

<T,F> T getTransparentXmlWrapper(java.lang.Class<T> transparentXmlIF,
                                 F objectReference,
                                 java.lang.Class<F> flatXmlIF)
                          throws AcsJContainerServicesEx

Converts a "flat-XML" remote object (RO) interface (as obtained from the various getComponent methods, in the case of components, or by retrieving offshoots from components, in the case of offshoots) to a "transparent-XML" RO interface. This is only applicable to ROs that contain XML entities in their IDL interface methods, and for which the build process has been set up to generate XML binding classes and the "transparent-XML" interface in addition to the standard Java-IDL compiler output.

In the case that the remote object is a component, the container can fulfill this request in two different ways:

1. Remote component: if the specified component runs in a different container, a dynamic wrapper object will be created around the provided CORBA stub. The wrapper object will translate between entity object parameters in the form of serialized XML (as found in flatXmlIF) and the corresponding Java binding classes (in transparentXmlIF).
2. Collocated component: if the specified component runs in the same container, the container may choose to shortcut the (de-) serialization of XML binding classes. In this case, Java binding classes are transported in memory, and all communication with the other component is done without CORBA.

In either case, the returned Object implements the transparentXmlIF interface. The client component that calls this method should only cast to that interface, and does not need to know which of the two transport mechanisms are being used.

Parameters:

transparentXmlIF - remote object interface with XML binding classes.

objectReference - reference to the remote object to be wrapped, which implements flatXmlIF. Currently supported remote objects are ACS Components and OffShoots.

flatXmlIF - remote object interface ("xxxOperations") where entity objects are represented as serialized XML inside a CORBA struct.

Returns:

the object that implements transparentXmlIF.

Throws:

AcsJContainerServicesEx

activateOffShoot

<T extends OffShootOperations> OffShoot activateOffShoot(T offshootImpl,
                                                         java.lang.Class<T> idlOpInterface)
                                                  throws AcsJContainerServicesEx

Activates an Object as an OffShoot.

In contrast to the old ContainerServicesBase.activateOffShoot(Servant) method, which always expects a Servant (either subclass of xyzPOA skeleton or a xyzPOATie instance), this method is more flexible and receives two arguments:

• The object implementing alma.ACS.OffShootOperations, but without restricting it to be a Servant, and
• The operations interface that this object directly implements.

This way, we support

• Activation of "normal" OffShoots:
  offshootImpl should be a corba Servant, either a subclass of the XyzPOA skeleton, or a XyzPOATie instance (delegation model).
  idlOpInterface should be XyzOperations.class.
• OffShoots featuring automatic XML (de-)serialization, similar to what has always been offered for ACS Components.
  offshootImpl should be an object that implements the generated XyzJ interface (which uses XML binding classes and extends OffShootOperations). This object is not expected to be a Corba Servant.
  idlOpInterface should be XyzJ.class.

Since ACS 9.0, when giving an OffShoot with XML entities (de-)serialization, automatic interception code is created to wrap the given object, and a XyzPOATie instance is created automatically and used as the servant. Since ACS 4.1.2, a tie servant is detected, and interception code gets inserted between the POATie skeleton and the offshoot implementation class. This way, the container can intercept (and log) calls to offshoots in the same way as it does for calls to components. It is therefore recommended to use the tie approach for all offshoot servants, unless there is a reason to avoid container interception.

Type Parameters:

T - The type of offshootImpl, one of the xyzJ or xyzOperations interfaces

Parameters:

offshootImpl - the object that implements the OffShoot logic

idlOpInterface - the IDL operations interface implemented by offshootImpl; currently, must be one of xyzOperations or xyzJ

Returns:

The Corba-activated offshoot object. Needs a narrow-cast to the subtype, like CBdouble myCBdouble = alma.ACS.CBdoubleHelper.narrow(...).

Throws:

AcsJContainerServicesEx - if anything goes wrong, especially if offshootImpl is does not implement alma.ACS.OffShootOperations.

Since:

ACS 9.0

getAlarmSource

AlarmSource getAlarmSource()

Returns the AlarmSource owned by this object. The AlarmSource object allows to raise and clear alarms, among other advanced operations

Returns:

The AlarmSource owned by this object