com.phoenixst.plexus.examples
Class FileSystemForest

java.lang.Object
  com.phoenixst.plexus.AbstractGraph
      com.phoenixst.plexus.examples.FileSystemForest

All Implemented Interfaces:

Graph, OrientedForest

public class FileSystemForest
extends AbstractGraph
implements OrientedForest

A lazy forest graph of the local file system. The single instance of this class should be retrieved through the getInstance() method.

Since:

1.0

Version:

$Revision: 1.21 $

Author:

Ray A. Conner

Nested Class Summary

Nested classes/interfaces inherited from interface com.phoenixst.plexus.Graph

Graph.Edge

Method Summary

Traverser	childTraverser(Object node) Traverses over the children of the specified node.
boolean	containsEdge(Graph.Edge edge) This implementation traverses over the edges in this graph incident on the tail of the specified edge, looking for it and returning true if found.
boolean	containsNode(Object node) This implementation iterates over the nodes in this graph looking for the specified element.
int	degree(Object node) This implementation counts the number of elements accessed by this graph's traverser( node, null ) method, counting self-loops twice.
protected Collection	edges() Returns a Collection view of all the Graph.Edges in this Graph.
int	getDepth(Object node) Gets the depth of the specified node.
int	getHeight(Object node) Gets the height of the specified node.
static FileSystemForest	getInstance()
Object	getLeastCommonAncestor(Object aNode, Object bNode) Returns the least common ancestor of the specified nodes, or null if none exists.
Object	getParent(Object node) Gets the parent of the specified node, or null if it doesn't have one.
Graph.Edge	getParentEdge(Object node) Gets the parent Edge of the specified node, or null if it doesn't have one.
Object	getParentEndpoint(Graph.Edge edge) Returns the parent endpoint of the specified forest Edge.
Object	getRoot(Object node) Gets the root of the subgraph containing the specified node.
boolean	isAncestor(Object ancestor, Object descendant) Returns true if ancestor is actually an ancestor of descendant.
boolean	isForestEdge(Graph.Edge edge) Gets whether or not the specified Edge is a forest edge.
boolean	isLeaf(Object node) Returns true if the specified node has no children.
protected Collection	nodes() Returns a Collection view of all the nodes in this Graph.
boolean	removeNode(Object node) This implementation iterates over the nodes in this graph looking for the specified element.
Collection	rootNodes() Returns the root nodes of this forest.
protected Traverser	traverser(Object node) Returns an unfiltered Traverser over those Graph.Edges incident to the specified node.

Methods inherited from class com.phoenixst.plexus.AbstractGraph

addEdge, addNode, adjacentNodes, degree, edges, getAdjacentNode, getEdge, getIncidentEdge, getNode, incidentEdges, nodes, removeEdge, traverser

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static final FileSystemForest getInstance()

nodes

protected Collection nodes()

Description copied from class: AbstractGraph

Returns a Collection view of all the nodes in this Graph. This method is only called by nodes( Predicate ).

Specified by:

nodes in class AbstractGraph

edges

protected Collection edges()

Description copied from class: AbstractGraph

Returns a Collection view of all the Graph.Edges in this Graph. This method is only called by edges( Predicate ).

Specified by:

edges in class AbstractGraph

traverser

protected Traverser traverser(Object node)

Description copied from class: AbstractGraph

Returns an unfiltered Traverser over those Graph.Edges incident to the specified node. This method is only called by traverser( node, Predicate ).

Specified by:

traverser in class AbstractGraph

degree

public int degree(Object node)

Description copied from class: AbstractGraph

This implementation counts the number of elements accessed by this graph's traverser( node, null ) method, counting self-loops twice.

Specified by:

degree in interface Graph

Overrides:

degree in class AbstractGraph

Parameters:

node - return the degree of this node.

Returns:

the degree of node.

containsNode

public boolean containsNode(Object node)

Description copied from class: AbstractGraph

This implementation iterates over the nodes in this graph looking for the specified element.

Specified by:

containsNode in interface Graph

Overrides:

containsNode in class AbstractGraph

Parameters:

node - the node whose presence in this Graph is to be tested.

Returns:

true if this Graph contains the specified node.

removeNode

public boolean removeNode(Object node)

Description copied from class: AbstractGraph

This implementation iterates over the nodes in this graph looking for the specified element. If it finds the element, it removes the element using using the Iterator.remove() operation.

Note that this implementation will throw an UnsupportedOperationException if the iterator returned by this graph's nodes( null ).iterator() method does not implement the remove method and this graph contains the specified node.

Specified by:

removeNode in interface Graph

Overrides:

removeNode in class AbstractGraph

Parameters:

node - the node to be removed from this Graph.

Returns:

true if this Graph contained node.

containsEdge

public boolean containsEdge(Graph.Edge edge)

Description copied from class: AbstractGraph

This implementation traverses over the edges in this graph incident on the tail of the specified edge, looking for it and returning true if found.

Specified by:

containsEdge in interface Graph

Overrides:

containsEdge in class AbstractGraph

Parameters:

edge - the Graph.Edge whose presence in this Graph is to be tested.

Returns:

true if this Graph contains the specified Graph.Edge.

getParent

public Object getParent(Object node)

Description copied from interface: OrientedForest

Gets the parent of the specified node, or null if it doesn't have one. If null is a valid node, then OrientedForest.getParentEdge(java.lang.Object) must be used to distinguish the two cases.

Specified by:

getParent in interface OrientedForest

childTraverser

public Traverser childTraverser(Object node)

Description copied from interface: OrientedForest

Traverses over the children of the specified node.

Specified by:

childTraverser in interface OrientedForest

getParentEdge

public Graph.Edge getParentEdge(Object node)

Description copied from interface: OrientedForest

Gets the parent Edge of the specified node, or null if it doesn't have one.

Specified by:

getParentEdge in interface OrientedForest

isForestEdge

public boolean isForestEdge(Graph.Edge edge)

Description copied from interface: OrientedForest

Gets whether or not the specified Edge is a forest edge.

Specified by:

isForestEdge in interface OrientedForest

getParentEndpoint

public Object getParentEndpoint(Graph.Edge edge)

Description copied from interface: OrientedForest

Returns the parent endpoint of the specified forest Edge. If the specified Edge is not a forest edge, throws an IllegalArgumentException.

Specified by:

getParentEndpoint in interface OrientedForest

rootNodes

public Collection rootNodes()

Description copied from interface: OrientedForest

Returns the root nodes of this forest.

Specified by:

rootNodes in interface OrientedForest

getRoot

public Object getRoot(Object node)

Description copied from interface: OrientedForest

Gets the root of the subgraph containing the specified node.

Specified by:

getRoot in interface OrientedForest

isLeaf

public boolean isLeaf(Object node)

Description copied from interface: OrientedForest

Returns true if the specified node has no children.

Specified by:

isLeaf in interface OrientedForest

isAncestor

public boolean isAncestor(Object ancestor,
                          Object descendant)

Description copied from interface: OrientedForest

Returns true if ancestor is actually an ancestor of descendant.

Specified by:

isAncestor in interface OrientedForest

getLeastCommonAncestor

public Object getLeastCommonAncestor(Object aNode,
                                     Object bNode)

Description copied from interface: OrientedForest

Returns the least common ancestor of the specified nodes, or null if none exists. If null is a valid node, then some other method must be used to distinguish the two cases.

Specified by:

getLeastCommonAncestor in interface OrientedForest

getDepth

public int getDepth(Object node)

Description copied from interface: OrientedForest

Gets the depth of the specified node.

Specified by:

getDepth in interface OrientedForest

getHeight

public int getHeight(Object node)

Description copied from interface: OrientedForest

Gets the height of the specified node.

Specified by:

getHeight in interface OrientedForest