consciouscode.seedling.tree
Class StandardBranch

java.lang.Object
  consciouscode.seedling.tree.GenericNode
      consciouscode.seedling.tree.GenericBranch
          consciouscode.seedling.tree.StandardBranch

All Implemented Interfaces:

BranchingBranch, BranchNode, EventfulBranch, GrowingBranch, LocatableNode, ServiceNode

Direct Known Subclasses:

ScopeRoot, StandardRoot

public class StandardBranch
extends GenericBranch
implements BranchingBranch

The canonical implementation of BranchNode, providing dynamic node provisioning via a NodeProvider.

Field Summary

protected NodeProvider

myNodeProvider

Constructor Summary

StandardBranch()
Constructs a new branch, inheriting its NodeProvider from its parent branch.

StandardBranch(NodeProvider nodeProvider)

Method Summary

Collection<String>	availableChildNames() Extracts a collection of the names of child nodes that are available on request from this branch.
protected StandardBranch	constructChildBranch() Strategy method called by GenericBranch.provisionChildBranch() to do initial construction of child branches.
NodeProvider	getNodeProvider() Returns the object responsible for provisioning nodes for this branch.
void	nodeInstalled(NodeLocation location) Register the Seedling address at which this node has been installed.
protected Object	provisionChild(String nodeName) Attempts to provision a child node, where one doesn't currently exist.

Methods inherited from class consciouscode.seedling.tree.GenericBranch

addBranchChangeListener, availableChild, createChild, fireChildInstalled, fireChildUninstalled, getChild, getInstalledNode, getLocalPathForChild, getLocalRoot, getNode, installChild, installedChild, installedChildNames, provisionChildBranch, startService, stopService, uninstallChild

Methods inherited from class consciouscode.seedling.tree.GenericNode

getLog, getNodeLocation, getNodeName, getParentBranch, isLoggingDebug, setLog, setLoggingDebug

Methods inherited from class java.lang.Object

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

Methods inherited from interface consciouscode.seedling.BranchingBranch

provisionChildBranch

Methods inherited from interface consciouscode.seedling.GrowingBranch

installChild, uninstallChild

Methods inherited from interface consciouscode.seedling.BranchNode

availableChild, getChild, getInstalledNode, getLocalRoot, getLog, getNode, installedChild, installedChildNames

Methods inherited from interface consciouscode.seedling.LocatableNode

getNodeLocation

Methods inherited from interface consciouscode.seedling.ServiceNode

startService, stopService

Field Detail

myNodeProvider

protected NodeProvider myNodeProvider

Constructor Detail

StandardBranch

public StandardBranch()

Constructs a new branch, inheriting its NodeProvider from its parent branch. This can only be installed inside another instance of StandardBranch.

See Also:

nodeInstalled(NodeLocation)

StandardBranch

public StandardBranch(NodeProvider nodeProvider)

Method Detail

getNodeProvider

public NodeProvider getNodeProvider()

Returns the object responsible for provisioning nodes for this branch.

Returns:

this branch's node provider (not null).

availableChildNames

public Collection<String> availableChildNames()

Description copied from interface: BranchNode

Extracts a collection of the names of child nodes that are available on request from this branch. This set includes all installed children, as well as any other nodes that could be created on demand (usually via automated injection from configuration files).

The result is a snapshot of the current state: subsequent changes to the branch are not reflected in the result. Thus the actual children may have changed by the time the collection is inspected; in particular, another thread may uninstall a node named in this collection (thereby making it unavailable) before the name is even read from this collection.

Implementations must ensure that the result stays usable even when the branch changes in another thread. For example, iterating the result must not throw ConcurrentModificationException if the branch changes during iteration.

Specified by:

availableChildNames in interface BranchNode

Overrides:

availableChildNames in class GenericBranch

Returns:

not null.

nodeInstalled

public void nodeInstalled(NodeLocation location)

Description copied from class: GenericBranch

Register the Seedling address at which this node has been installed. This is called immediately after the node has been installed into the tree.

Note: This is not called setNodeLocation because the location is not intended as a writable property. This implementation calls super and then caches the location's local root.

Specified by:

nodeInstalled in interface LocatableNode

Overrides:

nodeInstalled in class GenericBranch

Parameters:

location - is this node's new location. It must not be null.

See Also:

GenericBranch.getLocalRoot()

constructChildBranch

protected StandardBranch constructChildBranch()

Description copied from class: GenericBranch

Strategy method called by GenericBranch.provisionChildBranch() to do initial construction of child branches. Subclasses will generally override this to construct a new instance of their own class.

Overrides:

constructChildBranch in class GenericBranch

Returns:

a new GenericBranch.

See Also:

GenericBranch.provisionChildBranch()

provisionChild

protected Object provisionChild(String nodeName)
                         throws NodeProvisioningException

Description copied from class: GenericBranch

Attempts to provision a child node, where one doesn't currently exist. This is not guaranteed to succeed; for instance there may be no appropriate configuration, or the branch may not support automatic child provisioning.

This implementation always returns null.

Overrides:

provisionChild in class GenericBranch

Returns:

the newly-created child node, or null if the node is not available.

Throws:

NodeProvisioningException - if there's a problem provisioning the node.