org.globus.cog.util.graph
Class Graph

java.lang.Object
  org.globus.cog.util.graph.Graph

All Implemented Interfaces:

Cloneable, GraphInterface

public class Graph

extends Object

implements GraphInterface

Implements the graph interface

See Also:

org.globus.ogce.util.Graph, org.globus.ogce.util.GraphEdge, org.globus.ogce.util.GraphNode

Constructor Summary

Graph()
Constructs a new Graph object without any nodes or edges

Method Summary

Edge	addEdge(Node FromNode, Node ToNode, Object contents) Adds an edge from FromNode to ToNode
void	addGraphListener(GraphListener l) Adds a listener to listen for structural changes in the graph
Node	addNode() Creates a new node in the graph
Node	addNode(Object Contents) Creates a new node storing Contents in it
void	clear() Removes all nodes and edges from this graph
Object	clone() Returns a shallow copy of the graph.
int	edgeCount() Returns No of edges in the graph
boolean	equals(Object o) Determines if the specified graph is structurally equivalen to the specified graph.
Edge	findEdge(Object contents)
Node	findNode(Object contents) Finds the node that has the specified contents
EdgeIterator	getEdgesIterator() Returns an iterator with the edges in the graph
Set	getEdgesSet() Returns a list with the edges in the graph.
NodeIterator	getNodesIterator() Returns an iterator with all the nodes in the graph
Set	getNodesSet() Returns a list with the nodes in the graph.
int	hashCode()
int	nodeCount() Returns No of nodes in the graph
void	removeEdge(Edge edge) Removes an edge from the graph
void	removeEdge(Node fromNode, Node toNode) Removes an edge going from FromNode to ToNode
void	removeGraphListener(GraphListener l) Removes a listener
void	removeNode(Node node) Removes the specified node from the graph It will also remove all the edges connected to the node

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Graph

public Graph()

Constructs a new Graph object without any nodes or edges

Method Detail

addGraphListener

public void addGraphListener(GraphListener l)

Description copied from interface: GraphInterface

Adds a listener to listen for structural changes in the graph

Specified by:

addGraphListener in interface GraphInterface

Parameters:

l - the listener to be added

removeGraphListener

public void removeGraphListener(GraphListener l)

Description copied from interface: GraphInterface

Removes a listener

Specified by:

removeGraphListener in interface GraphInterface

Parameters:

l -

clear

public void clear()

Description copied from interface: GraphInterface

Removes all nodes and edges from this graph

Specified by:

clear in interface GraphInterface

addNode

public Node addNode()

Creates a new node in the graph

Specified by:

addNode in interface GraphInterface

Returns:

a reference to the newly created node

addNode

public Node addNode(Object Contents)

Creates a new node storing Contents in it

Specified by:

addNode in interface GraphInterface

Parameters:

Contents - The feature to be added to the Node attribute

Returns:

a reference to the newly created node

addEdge

public Edge addEdge(Node FromNode,
                    Node ToNode,
                    Object contents)
             throws NodeNotFoundException

Adds an edge from FromNode to ToNode

Specified by:

addEdge in interface GraphInterface

Parameters:

FromNode - the node the edge starts from

ToNode - the node the edge goes to

contents - The object to be stored in the edge

Returns:

The newly created edge

Throws:

NodeNotFoundException - If one of the specified nodes is not found

edgeCount

public int edgeCount()

Returns No of edges in the graph

Specified by:

edgeCount in interface GraphInterface

Returns:

Description of the Return Value

nodeCount

public int nodeCount()

Returns No of nodes in the graph

Specified by:

nodeCount in interface GraphInterface

Returns:

Description of the Return Value

getNodesIterator

public NodeIterator getNodesIterator()

Returns an iterator with all the nodes in the graph

Specified by:

getNodesIterator in interface GraphInterface

Returns:

The nodesIterator value

getNodesSet

public Set getNodesSet()

Description copied from interface: GraphInterface

Returns a list with the nodes in the graph. The order of nodes is a given. New nodes are added at the end of the list. This method allows manipulation of the graph based on the indexes of nodes.

Specified by:

getNodesSet in interface GraphInterface

Returns:

the list of nodes in this graph

getEdgesIterator

public EdgeIterator getEdgesIterator()

Returns an iterator with the edges in the graph

Specified by:

getEdgesIterator in interface GraphInterface

Returns:

The edgesIterator value

getEdgesSet

public Set getEdgesSet()

Description copied from interface: GraphInterface

Returns a list with the edges in the graph. The order of edges should not change between calls to this method, unless changes are made to the graph. New edges are added at the end of the list. This method allows manipulation of the graph based on the indexes of edges.

Specified by:

getEdgesSet in interface GraphInterface

Returns:

the list of edges in this graph

removeNode

public void removeNode(Node node)
                throws NodeNotFoundException

Removes the specified node from the graph It will also remove all the edges connected to the node

Specified by:

removeNode in interface GraphInterface

Parameters:

node - Description of the Parameter

Throws:

NodeNotFoundException - thrown if the node was not found in this graph

removeEdge

public void removeEdge(Node fromNode,
                       Node toNode)
                throws NodeNotFoundException,
                       EdgeNotFoundException

Removes an edge going from FromNode to ToNode

Specified by:

removeEdge in interface GraphInterface

Parameters:

fromNode - Description of the Parameter

toNode - Description of the Parameter

Throws:

NodeNotFoundException - Description of the Exception

EdgeNotFoundException - Description of the Exception

removeEdge

public void removeEdge(Edge edge)
                throws EdgeNotFoundException

Removes an edge from the graph

Specified by:

removeEdge in interface GraphInterface

Parameters:

edge - Description of the Parameter

Throws:

EdgeNotFoundException - Description of the Exception

findEdge

public Edge findEdge(Object contents)

Specified by:

findEdge in interface GraphInterface

findNode

public Node findNode(Object contents)

Description copied from interface: GraphInterface

Finds the node that has the specified contents

Specified by:

findNode in interface GraphInterface

clone

public Object clone()

Returns a shallow copy of the graph. The Node and Edge objects will be different, but their contained objects will remain the same

Specified by:

clone in interface GraphInterface

Returns:

the cloned graph

equals

public boolean equals(Object o)

Determines if the specified graph is structurally equivalen to the specified graph. Structural equivalence, in this case, means: Given graph A and B:

• The number of nodes and edges are the same for A and B
• Nodes from A and B having the same index in the nodes list contain the same objects
• Edges from A and B having the same index in the edges list contain the same objects
• Edges from A and B having the same index in the edges list point to (and from) nodes with the same indices
The objects contained within nodes and edges are compare using equals()

Parameters:

o - The object to be compared to this graph

Returns:

True if the graphs are equivalent

hashCode

public int hashCode()