com.kedwards.swt
Interface ServiceBackend

All Superinterfaces:

Checkpointed

All Known Implementing Classes:

ActivatableServiceBackend, UnicastServiceBackend

public interface ServiceBackend

extends Checkpointed

ServiceBackend.java

The stages in a service backend's life are:

• Creation. Most backends won't do much during this stage.
• preInitialize() is called. This is a chance for the backend to do any initialization that--for whatever reason--it doesn't want to do in its constructor. At this point the wrapper has been created (which is accessible to the backend via getServiceWrapper), debug flags have been parsed, a security manager is installed, a class exporter is running, and a persistifier has been loaded.
• After this, EITHER recoverFromCheckpointState OR initialize will be called. RecoverFromCheckPointState is called only if the service is restoring from checkpointed data. The backend uses this opportunity to initialize any backend-specific state from the loaded data. NOTE that the method is not called if the service has no checkpoint file from a previous run. Initialize is called only for the service to do any first-run set up that may be needed.
• postInitialize() is called as soon as the service ID is known. This will happen immediately if the service has been recovered from checkpoint data (and note that this doesn't necessarily mean that any lookup services have been discovered), and asynchronously at some indeterminant point in the future, when a lookup service is discovered, if this is the first time the service has been run. Any services that REQUIRE a service ID (for whatever reason) before they can fully initialize themselves should do such initialization at this point.
• shutdown() is called when the wrapper is terminated (usually through the administrative interfaces).

Thus, the order is:

creation - preInit - (restore|init) -> postInit - shutdown

See http://www.kedwards.com/jini

No warranty expressed or implied; use at your own risk; for educational purposes only.

Author:

Keith Edwards

Method Summary

java.lang.Object	getAdmin() Optionally called by the service's to get the admin proxy when asked.
net.jini.core.entry.Entry[]	getInitialAttributes() Services can specify their initial attributes.
java.lang.String[]	getInitialGroups() Services can specify their initial lookup groups.
net.jini.core.discovery.LookupLocator[]	getInitialLocators() Services can specify their initial lookup locators.
java.lang.Object	getProxy() Called by the service wrapper to fetch the proxy for publication.
java.lang.String	getServiceName() Return a name for this service; this will likely be the same name attached in a Name attribute.
ServiceWrapper	getServiceWrapper() Gets the current service wrapper.
void	initialize() Called the first time the service is run, before a JoinManager is created.
void	postInitialize() Called by the service wrapper once the service ID has been set.
void	preInitialize() Called by the service wrapper for post-construction initialization after the sevice wrapper is all set to go.
void	setServiceID(net.jini.core.lookup.ServiceID serviceID) Called when the service's ID is available to inform the backend of its ID.
void	setServiceWrapper(ServiceWrapper wrapper) Sets the current service wrapper.
void	shutdown() Called by the service wrapper when the backend should be terminated.

Methods inherited from interface com.kedwards.swt.persist.Checkpointed

getCheckpointData, setCheckpointData

Method Detail

getServiceName

public java.lang.String getServiceName()

Return a name for this service; this will likely be the same name attached in a Name attribute.

Returns:

The name of the service.

getProxy

public java.lang.Object getProxy()
                          throws java.rmi.RemoteException

Called by the service wrapper to fetch the proxy for publication.

Returns:

The service's proxy.

getAdmin

public java.lang.Object getAdmin()
                          throws java.rmi.RemoteException

Optionally called by the service's to get the admin proxy when asked.

Returns:

An admin object for the service.

preInitialize

public void preInitialize()
                   throws java.lang.Exception

Called by the service wrapper for post-construction initialization after the sevice wrapper is all set to go.

initialize

public void initialize()
                throws java.lang.Exception

Called the first time the service is run, before a JoinManager is created.

postInitialize

public void postInitialize()
                    throws java.lang.Exception

Called by the service wrapper once the service ID has been set.

shutdown

public void shutdown()

Called by the service wrapper when the backend should be terminated.

setServiceWrapper

public void setServiceWrapper(ServiceWrapper wrapper)

Sets the current service wrapper. Should only be called once.

getServiceWrapper

public ServiceWrapper getServiceWrapper()

Gets the current service wrapper.

getInitialGroups

public java.lang.String[] getInitialGroups()

Services can specify their initial lookup groups. The value returned from this method will only be used on the initial run.

getInitialLocators

public net.jini.core.discovery.LookupLocator[] getInitialLocators()

Services can specify their initial lookup locators. The value returned from this method will only be used on the initial run.

getInitialAttributes

public net.jini.core.entry.Entry[] getInitialAttributes()

Services can specify their initial attributes. The value returned from this method will only be used on the initial run.

setServiceID

public void setServiceID(net.jini.core.lookup.ServiceID serviceID)

Called when the service's ID is available to inform the backend of its ID.