org.thegalactic.dgraph

Class Edge<N,E>

java.lang.Object

org.thegalactic.dgraph.Edge<N,E>

Type Parameters:

N -

E -

All Implemented Interfaces:

Comparable<Edge<N,E>>

public class Edge<N,E>
extends Object
implements Comparable<Edge<N,E>>

This class gives a standard representation for an edge of a graph.

An edge is composed of a content, and two nodes

• source
• target

of class Node.

This class implements class Comparable and provides the compareTo(org.thegalactic.dgraph.Edge<N, E>) method that compares the edge with those in parameter by sorting indexes of the nodes that compose it.

Therefore, edges can be stored in a sorted collection since they are comparable, and in particular in a sorted set where set operations are provided.

Constructor Summary

Constructors

Constructor and Description
Edge(Node<N> source, Node<N> target) Constructs a new edge with the specified node as origin and destination node, and a null value as content.
Edge(Node<N> source, Node<N> target, E content) Constructs a new edge with the specified node as origin and destination node, with the specified content.

Method Summary

Modifier and Type	Method and Description
int	compareTo(Edge<N,E> edge) Compares this edge with those in parameter, based on their identifiers.
boolean	equals(Object object) Compares this edge with the specified one.
E	getContent() Returns the content this edge.
Node<N>	getSource() Returns the source node of this edge.
Node<N>	getTarget() Returns the target node of this edge.
boolean	hasContent() Returns true if content of this edge is not the null value.
int	hashCode() Compute the hash code.
Edge<N,E>	setContent(E content) Replaces the content of this edge with the specified one.
String	toString() Returns a String representation of this edge.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Edge

public Edge(Node<N> source,
            Node<N> target,
            E content)

Constructs a new edge with the specified node as origin and destination node, with the specified content.

Parameters:

source - the origin node

target - the destination node

content - the edge content

Edge

public Edge(Node<N> source,
            Node<N> target)

Constructs a new edge with the specified node as origin and destination node, and a null value as content.

Parameters:

source - the origin node

target - the destination node

Method Detail

getSource

public final Node<N> getSource()

Returns the source node of this edge.

Returns:

the source node

getTarget

public final Node<N> getTarget()

Returns the target node of this edge.

Returns:

the target node

setContent

public final Edge<N,E> setContent(E content)

Replaces the content of this edge with the specified one.

Parameters:

content - The edge content

Returns:

this for chaining

getContent

public final E getContent()

Returns the content this edge.

Returns:

the content

hasContent

public final boolean hasContent()

Returns true if content of this edge is not the null value.

Returns:

true if the content is not null

equals

public boolean equals(Object object)

Compares this edge with the specified one.

Overrides:

equals in class Object

Parameters:

object - The object target be tested with

Returns:

true or false as this node is equal target the specified object.

hashCode

public int hashCode()

Compute the hash code.

Overrides:

hashCode in class Object

Returns:

an integer representing the object

compareTo

public final int compareTo(Edge<N,E> edge)

Compares this edge with those in parameter, based on their identifiers.

The result is zero if the identifiers are equal; positive if this edge’s identifier is greater, and negative otherwise.

This comparison method is needed target define a natural ordering. It allows target use objects of this class in a sorted collection

Specified by:

compareTo in interface Comparable<Edge<N,E>>

Parameters:

edge - the specified element target be compared with this edge

Returns:

a negative integer, zero, or a positive integer as this edge is less than, equal target, or greater than the specified object.

toString

public String toString()

Returns a String representation of this edge.

Overrides:

toString in class Object

Returns:

The string representation of this edge