de.ipcon.tools.graph

Class DefaultGraphEdge

java.lang.Object

de.ipcon.tools.graph.DefaultGraphEdge

All Implemented Interfaces:

GraphEdgeI

public class DefaultGraphEdge
extends java.lang.Object
implements GraphEdgeI

A straightforward, immutable implementation of the GraphEdgeI interface.

This class represents a directed edge connecting a specified source node (fromNode) to a target node (toNode). Both nodes are instances of OnlyToDirectedGraphNodeI.

Instances of DefaultGraphEdge are immutable: the source and target nodes are set at construction time via the constructor DefaultGraphEdge(OnlyToDirectedGraphNodeI, OnlyToDirectedGraphNodeI) and cannot be changed thereafter. This design makes them inherently thread-safe and suitable for use in various graph data structures and algorithms.

This class also provides standard and consistent implementations for equals(Object), hashCode(), and toString() methods, making it well-behaved for use in collections and for debugging.

See Also:

The interface this class implements., The type of the nodes connected by this edge.

Constructor Summary

Constructors

Constructor and Description
DefaultGraphEdge(OnlyToDirectedGraphNodeI fromNode, OnlyToDirectedGraphNodeI toNode) Constructs a new DefaultGraphEdge connecting the specified source and target nodes.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o) Indicates whether some other object is "equal to" this one.
OnlyToDirectedGraphNodeI	getFromNode() Retrieves the source node from which this directed edge originates.
OnlyToDirectedGraphNodeI	getToNode() Retrieves the target node to which this directed edge points.
int	hashCode() Returns a hash code value for the edge.
java.lang.String	toString() Returns a string representation of this edge, primarily for debugging and logging.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DefaultGraphEdge

public DefaultGraphEdge(OnlyToDirectedGraphNodeI fromNode,
                        OnlyToDirectedGraphNodeI toNode)

Constructs a new DefaultGraphEdge connecting the specified source and target nodes.

Parameters:

fromNode - The non-null source node (from-node or tail) from which this edge originates.

toNode - The non-null target node (to-node or head) to which this edge points.

Throws:

java.lang.IllegalArgumentException - if either fromNode or toNode is null.

Method Detail

getFromNode

public OnlyToDirectedGraphNodeI getFromNode()

Retrieves the source node from which this directed edge originates.

This method is contractually obligated to return a non-null OnlyToDirectedGraphNodeI instance, as every valid edge must have a defined starting point.

In this implementation, this method returns the source node that was provided at the time of construction.

Specified by:

getFromNode in interface GraphEdgeI

Returns:

The non-null source node of this edge, as specified during construction.

getToNode

public OnlyToDirectedGraphNodeI getToNode()

Retrieves the target node to which this directed edge points.

This method is contractually obligated to return a non-null OnlyToDirectedGraphNodeI instance, as every valid edge must have a defined ending point.

In this implementation, this method returns the target node that was provided at the time of construction.

Specified by:

getToNode in interface GraphEdgeI

Returns:

The non-null target node of this edge, as specified during construction.

toString

public java.lang.String toString()

Returns a string representation of this edge, primarily for debugging and logging. The format is generally "DefaultGraphEdge{from=FROM_NODE_STRING, to=TO_NODE_STRING}".

Overrides:

toString in class java.lang.Object

Returns:

A string representation of this edge, typically including the string representations of its source and target nodes.

equals

public boolean equals(java.lang.Object o)

Indicates whether some other object is "equal to" this one.

Two DefaultGraphEdge instances are considered equal if they are of the same class and their source nodes are equal and their target nodes are equal. The equality of the nodes is determined by their respective equals methods.

Overrides:

equals in class java.lang.Object

Parameters:

o - The reference object with which to compare.

Returns:

true if this edge is the same as the o argument (i.e., same class, same from-node, and same to-node); false otherwise.

hashCode

public int hashCode()

Returns a hash code value for the edge. The hash code is calculated based on the hash codes of the source and target nodes, ensuring that two equal DefaultGraphEdge instances will have the same hash code.

Overrides:

hashCode in class java.lang.Object

Returns:

A hash code value for this edge.