Package org.apache.openjpa.lib.graph

Class Edge

  • public class Edge
extends java.lang.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

      Fields 
      Modifier and Type Field Description
      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

      Constructors 
      Constructor Description
      Edge​(java.lang.Object from, java.lang.Object to, boolean directed)
      Constructor.
      Edge​(java.lang.Object from, java.lang.Object to, boolean directed, java.lang.Object userObject)
      Constructor.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clearTraversal()
      Clear traversal info.
      java.util.List<Edge> getCycle()
      List of edges forming a cycle.
      java.lang.Object getFrom()
      Return the node the edge links from.
      java.lang.Object getOther​(java.lang.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.
      java.lang.Object getTo()
      Return the node the edge links to.
      int getType()
      Traversal bookkeeping info.
      java.lang.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​(java.lang.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​(java.lang.Object node)
      Return true if this edge links to the given node.
      void setCycle​(java.util.List<Edge> 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​(java.lang.Object obj)
      Arbitrary user object associated with the edge.
      void setWeight​(double weight)
      Set the weight of the edge.
      java.lang.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​(java.lang.Object from,
            java.lang.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​(java.lang.Object from,
            java.lang.Object to,
            boolean directed,
            java.lang.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 java.lang.Object getFrom()
        Return the node the edge links from.

      • getTo

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

      • getOther

        public java.lang.Object getOther​(java.lang.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​(java.lang.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​(java.lang.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 java.lang.Object getUserObject()
        Arbitrary user object associated with the edge.

      • setUserObject

        public void setUserObject​(java.lang.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 java.util.List<Edge> getCycle()
        List of edges forming a cycle. Only set for TYPE_BACK and TYPE_FORWARD edges.

      • setCycle

        public void setCycle​(java.util.List<Edge> 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 java.lang.String toString()
        Overrides:
        toString in class java.lang.Object