org.apache.openjpa.lib.graph
Class Edge

java.lang.Object
  extended by org.apache.openjpa.lib.graph.Edge

public class Edge
extends Object

A graph edge. Includes the from and to nodes, an arbitrary user object, and a weight. Edges can be either directed or undirected.

Since:
1.0.0
Author:
Abe White

Field Summary
static int TYPE_BACK
          An edge (u, v) is a back edge if it creates a cycle back to an ancestor in the graph.
static int TYPE_FORWARD
          An edge (u, v) is a forward edge if it is not a tree or back edge.
static int TYPE_TREE
          An edge (u, v) is a tree edge if node v was first discovered by traversing the edge.
 
Constructor Summary
Edge(Object from, Object to, boolean directed)
          Constructor.
Edge(Object from, Object to, boolean directed, Object userObject)
          Constructor.
 
Method Summary
 void clearTraversal()
          Clear traversal info.
 List getCycle()
          List of edges forming a cycle.
 Object getFrom()
          Return the node the edge links from.
 Object getOther(Object node)
          Return the node on the opposite end of the given one, or null if the given node is not part of this edge.
 Object getTo()
          Return the node the edge links to.
 int getType()
          Traversal bookkeeping info.
 Object getUserObject()
          Arbitrary user object associated with the edge.
 double getWeight()
          Return the weight of the edge.
 boolean isDirected()
          Return whether the edge is directed.
 boolean isFrom(Object node)
          Return true if this edge links from the given node.
 boolean isRemovedFromGraph()
          Returns if this edge is (still) part of the graph.
 boolean isTo(Object node)
          Return true if this edge links to the given node.
 void setCycle(List cycle)
          List of edges forming a cycle.
 void setRemovedFromGraph()
          Mark this edge as removed from the graph.
 void setType(int type)
          Traversal bookkeeping info.
 void setUserObject(Object obj)
          Arbitrary user object associated with the edge.
 void setWeight(double weight)
          Set the weight of the edge.
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

TYPE_TREE

public static final int TYPE_TREE
An edge (u, v) is a tree edge if node v was first discovered by traversing the edge.

See Also:
Constant Field Values

TYPE_BACK

public static final int TYPE_BACK
An edge (u, v) is a back edge if it creates a cycle back to an ancestor in the graph.

See Also:
Constant Field Values

TYPE_FORWARD

public static final int TYPE_FORWARD
An edge (u, v) is a forward edge if it is not a tree or back edge.

See Also:
Constant Field Values
Constructor Detail

Edge

public Edge(Object from,
            Object to,
            boolean directed)
Constructor.

Parameters:
from - the node the edge comes from
to - the node the edge goes to
directed - whether the edge is directed

Edge

public Edge(Object from,
            Object to,
            boolean directed,
            Object userObject)
Constructor.

Parameters:
from - the node the edge comes from
to - the node the edge goes to
directed - whether the edge is directed
userObject - an associated object
Method Detail

getFrom

public Object getFrom()
Return the node the edge links from.


getTo

public Object getTo()
Return the node the edge links to.


getOther

public Object getOther(Object node)
Return the node on the opposite end of the given one, or null if the given node is not part of this edge.


isTo

public boolean isTo(Object node)
Return true if this edge links to the given node. For undirected edges, this method returns true if either side is equal to the given node.


isFrom

public boolean isFrom(Object node)
Return true if this edge links from the given node. For undirected edges, this method returns true if either side is equal to the given node.


isDirected

public boolean isDirected()
Return whether the edge is directed.


getWeight

public double getWeight()
Return the weight of the edge.


setWeight

public void setWeight(double weight)
Set the weight of the edge.


getUserObject

public Object getUserObject()
Arbitrary user object associated with the edge.


setUserObject

public void setUserObject(Object obj)
Arbitrary user object associated with the edge.


getType

public int getType()
Traversal bookkeeping info.


setType

public void setType(int type)
Traversal bookkeeping info.


getCycle

public List getCycle()
List of edges forming a cycle. Only set for TYPE_BACK and TYPE_FORWARD edges.


setCycle

public void setCycle(List cycle)
List of edges forming a cycle. Only set for TYPE_BACK and TYPE_FORWARD edges.


isRemovedFromGraph

public boolean isRemovedFromGraph()
Returns if this edge is (still) part of the graph.


setRemovedFromGraph

public void setRemovedFromGraph()
Mark this edge as removed from the graph.


clearTraversal

public void clearTraversal()
Clear traversal info.


toString

public String toString()
Overrides:
toString in class Object


Copyright © 2006-2009 Apache Software Foundation. All Rights Reserved.