 java.lang.Object

 org.jgrapht.graph.AbstractGraph<V,E>

 org.jgrapht.graph.AbstractBaseGraph<V,E>

 Type Parameters:
V
 the graph vertex typeE
 the graph edge type
 All Implemented Interfaces:
java.io.Serializable
,java.lang.Cloneable
,Graph<V,E>
 Direct Known Subclasses:
DefaultDirectedGraph
,DefaultUndirectedGraph
,DirectedAcyclicGraph
,DirectedMultigraph
,DirectedPseudograph
,FastutilMapGraph
,FastutilMapIntVertexGraph
,Multigraph
,Pseudograph
,SimpleDirectedGraph
,SimpleGraph
public abstract class AbstractBaseGraph<V,E> extends AbstractGraph<V,E> implements Graph<V,E>, java.lang.Cloneable, java.io.Serializable
The most general implementation of theGraph
interface.Its subclasses add various restrictions to get more specific graphs. The decision whether it is directed or undirected is decided at construction time and cannot be later modified (see constructor for details).
The behavior of this class can be adjusted by changing the
GraphSpecificsStrategy
that is provided from the constructor. All implemented strategies guarantee deterministic vertex and edge set ordering (viaLinkedHashMap
andLinkedHashSet
). The defaults are reasonable for most usecases, only change if you know what you are doing.The default graph implementations are not safe for concurrent reads and writes from different threads. If an application attempts to modify a graph in one thread while another thread is reading or writing the same graph, undefined behavior will result. However, concurrent reads against the same graph from different threads are safe. (Note that the
Graph interface
itself makes no such guarantee, so for nondefault implementations, different rules may apply.)If you need support for concurrent reads and writes, consider using the
AsSynchronizedGraph wrapper
. Author:
 Barak Naveh, Dimitrios Michail
 See Also:
 Serialized Form


Field Summary

Fields inherited from interface org.jgrapht.Graph
DEFAULT_EDGE_WEIGHT


Constructor Summary
Constructors Modifier Constructor Description protected
AbstractBaseGraph(java.util.function.Supplier<V> vertexSupplier, java.util.function.Supplier<E> edgeSupplier, GraphType type)
Construct a new graph.protected
AbstractBaseGraph(java.util.function.Supplier<V> vertexSupplier, java.util.function.Supplier<E> edgeSupplier, GraphType type, GraphSpecificsStrategy<V,E> graphSpecificsStrategy)
Construct a new graph.

Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description E
addEdge(V sourceVertex, V targetVertex)
Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.boolean
addEdge(V sourceVertex, V targetVertex, E e)
Adds the specified edge to this graph, going from the source vertex to the target vertex.V
addVertex()
Creates a new vertex in this graph and returns it.boolean
addVertex(V v)
Adds the specified vertex to this graph if not already present.java.lang.Object
clone()
Returns a shallow copy of this graph instance.boolean
containsEdge(E e)
Returnstrue
if this graph contains the specified edge.boolean
containsVertex(V v)
Returnstrue
if this graph contains the specified vertex.int
degreeOf(V vertex)
Returns the degree of the specified vertex.java.util.Set<E>
edgeSet()
Returns a set of the edges contained in this graph.java.util.Set<E>
edgesOf(V vertex)
Returns a set of all edges touching the specified vertex.java.util.Set<E>
getAllEdges(V sourceVertex, V targetVertex)
Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph.E
getEdge(V sourceVertex, V targetVertex)
Returns an edge connecting source vertex to target vertex if such vertices and such edge exist in this graph.V
getEdgeSource(E e)
Returns the source vertex of an edge.java.util.function.Supplier<E>
getEdgeSupplier()
Return the edge supplier that the graph uses whenever it needs to create new edges.V
getEdgeTarget(E e)
Returns the target vertex of an edge.double
getEdgeWeight(E e)
Returns the weight assigned to a given edge.GraphType
getType()
Get the graph type.java.util.function.Supplier<V>
getVertexSupplier()
Return the vertex supplier that the graph uses whenever it needs to create new vertices.java.util.Set<E>
incomingEdgesOf(V vertex)
Returns a set of all edges incoming into the specified vertex.int
inDegreeOf(V vertex)
Returns the "in degree" of the specified vertex.GraphIterables<V,E>
iterables()
Access the graph using theGraphIterables
interface.int
outDegreeOf(V vertex)
Returns the "out degree" of the specified vertex.java.util.Set<E>
outgoingEdgesOf(V vertex)
Returns a set of all edges outgoing from the specified vertex.boolean
removeEdge(E e)
Removes the specified edge from the graph.E
removeEdge(V sourceVertex, V targetVertex)
Removes an edge going from source vertex to target vertex, if such vertices and such edge exist in this graph.boolean
removeVertex(V v)
Removes the specified vertex from this graph including all its touching edges if present.void
setEdgeSupplier(java.util.function.Supplier<E> edgeSupplier)
Set the edge supplier that the graph uses whenever it needs to create new edges.void
setEdgeWeight(E e, double weight)
Set an edge weight.void
setVertexSupplier(java.util.function.Supplier<V> vertexSupplier)
Set the vertex supplier that the graph uses whenever it needs to create new vertices.java.util.Set<V>
vertexSet()
Returns a set of the vertices contained in this graph.
Methods inherited from class org.jgrapht.graph.AbstractGraph
assertVertexExist, containsEdge, equals, hashCode, removeAllEdges, removeAllEdges, removeAllEdges, removeAllVertices, toString, toStringFromSets

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.jgrapht.Graph
containsEdge, removeAllEdges, removeAllEdges, removeAllVertices, setEdgeWeight




Constructor Detail

AbstractBaseGraph
protected AbstractBaseGraph(java.util.function.Supplier<V> vertexSupplier, java.util.function.Supplier<E> edgeSupplier, GraphType type)
Construct a new graph. Parameters:
vertexSupplier
 the vertex supplier, can be nulledgeSupplier
 the edge supplier, can be nulltype
 the graph type Throws:
java.lang.IllegalArgumentException
 if the graph type is mixed

AbstractBaseGraph
protected AbstractBaseGraph(java.util.function.Supplier<V> vertexSupplier, java.util.function.Supplier<E> edgeSupplier, GraphType type, GraphSpecificsStrategy<V,E> graphSpecificsStrategy)
Construct a new graph. Parameters:
vertexSupplier
 the vertex supplier, can be nulledgeSupplier
 the edge supplier, can be nulltype
 the graph typegraphSpecificsStrategy
 strategy for constructing lowlevel graph specifics Throws:
java.lang.IllegalArgumentException
 if the graph type is mixed


Method Detail

getAllEdges
public java.util.Set<E> getAllEdges(V sourceVertex, V targetVertex)
Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph. If any of the vertices does not exist or isnull
, returnsnull
. If both vertices exist but no edges found, returns an empty set.In undirected graphs, some of the returned edges may have their source and target vertices in the opposite order. In simple graphs the returned set is either singleton set or empty set.
 Specified by:
getAllEdges
in interfaceGraph<V,E>
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge. Returns:
 a set of all edges connecting source vertex to target vertex.

getEdgeSupplier
public java.util.function.Supplier<E> getEdgeSupplier()
Description copied from interface:Graph
Return the edge supplier that the graph uses whenever it needs to create new edges.A graph uses the edge supplier to create new edge objects whenever a user calls method
Graph.addEdge(Object, Object)
. Users can also create the edge in user code and then use methodGraph.addEdge(Object, Object, Object)
to add the edge.In contrast with the
Supplier
interface, the edge supplier has the additional requirement that a new and distinct result is returned every time it is invoked. More specifically for a new edge to be added in a graphe
must not be equal to any other edge in the graph (even if the graph allows edgemultiplicity). More formally, the graph must not contain any edgee2
such thate2.equals(e)
. Specified by:
getEdgeSupplier
in interfaceGraph<V,E>
 Returns:
 the edge supplier
null
if the graph has no such supplier

setEdgeSupplier
public void setEdgeSupplier(java.util.function.Supplier<E> edgeSupplier)
Set the edge supplier that the graph uses whenever it needs to create new edges.A graph uses the edge supplier to create new edge objects whenever a user calls method
Graph.addEdge(Object, Object)
. Users can also create the edge in user code and then use methodGraph.addEdge(Object, Object, Object)
to add the edge.In contrast with the
Supplier
interface, the edge supplier has the additional requirement that a new and distinct result is returned every time it is invoked. More specifically for a new edge to be added in a graphe
must not be equal to any other edge in the graph (even if the graph allows edgemultiplicity). More formally, the graph must not contain any edgee2
such thate2.equals(e)
. Parameters:
edgeSupplier
 the edge supplier

getVertexSupplier
public java.util.function.Supplier<V> getVertexSupplier()
Description copied from interface:Graph
Return the vertex supplier that the graph uses whenever it needs to create new vertices.A graph uses the vertex supplier to create new vertex objects whenever a user calls method
Graph.addVertex()
. Users can also create the vertex in user code and then use methodGraph.addVertex(Object)
to add the vertex.In contrast with the
Supplier
interface, the vertex supplier has the additional requirement that a new and distinct result is returned every time it is invoked. More specifically for a new vertex to be added in a graphv
must not be equal to any other vertex in the graph. More formally, the graph must not contain any vertexv2
such thatv2.equals(v)
.Care must also be taken when interchanging calls to methods
Graph.addVertex(Object)
andGraph.addVertex()
. In such a case the user must make sure never to add vertices in the graph using methodGraph.addVertex(Object)
, which are going to be returned in the future by the supplied vertex supplier. Such a sequence will result into anIllegalArgumentException
when calling methodGraph.addVertex()
. Specified by:
getVertexSupplier
in interfaceGraph<V,E>
 Returns:
 the vertex supplier or
null
if the graph has no such supplier

setVertexSupplier
public void setVertexSupplier(java.util.function.Supplier<V> vertexSupplier)
Set the vertex supplier that the graph uses whenever it needs to create new vertices.A graph uses the vertex supplier to create new vertex objects whenever a user calls method
Graph.addVertex()
. Users can also create the vertex in user code and then use methodGraph.addVertex(Object)
to add the vertex.In contrast with the
Supplier
interface, the vertex supplier has the additional requirement that a new and distinct result is returned every time it is invoked. More specifically for a new vertex to be added in a graphv
must not be equal to any other vertex in the graph. More formally, the graph must not contain any vertexv2
such thatv2.equals(v)
.Care must also be taken when interchanging calls to methods
Graph.addVertex(Object)
andGraph.addVertex()
. In such a case the user must make sure never to add vertices in the graph using methodGraph.addVertex(Object)
, which are going to be returned in the future by the supplied vertex supplier. Such a sequence will result into anIllegalArgumentException
when calling methodGraph.addVertex()
. Parameters:
vertexSupplier
 the vertex supplier

getEdge
public E getEdge(V sourceVertex, V targetVertex)
Returns an edge connecting source vertex to target vertex if such vertices and such edge exist in this graph. Otherwise returnsnull
. If any of the specified vertices isnull
returnsnull
In undirected graphs, the returned edge may have its source and target vertices in the opposite order.

addEdge
public E addEdge(V sourceVertex, V targetVertex)
Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge. Some graphs do not allow edgemultiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, then this method does not change the graph and returnsnull
.The source and target vertices must already be contained in this graph. If they are not found in graph
IllegalArgumentException
is thrown.This method creates the new edge
e
using this graph's edge supplier (seeGraph.getEdgeSupplier()
). For the new edge to be addede
must not be equal to any other edge the graph (even if the graph allows edgemultiplicity). More formally, the graph must not contain any edgee2
such thate2.equals(e)
. If suche2
is found then the newly created edgee
is abandoned, the method leaves this graph unchanged and returnsnull
.If the underlying graph implementation's
Graph.getEdgeSupplier()
returnsnull
, then this method cannot create edges and throws anUnsupportedOperationException
. Specified by:
addEdge
in interfaceGraph<V,E>
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge. Returns:
 The newly created edge if added to the graph, otherwise
null
.  See Also:
Graph.getEdgeSupplier()

addEdge
public boolean addEdge(V sourceVertex, V targetVertex, E e)
Adds the specified edge to this graph, going from the source vertex to the target vertex. More formally, adds the specified edge,e
, to this graph if this graph contains no edgee2
such thate2.equals(e)
. If this graph already contains such an edge, the call leaves this graph unchanged and returnsfalse
. Some graphs do not allow edgemultiplicity. In such cases, if the graph already contains an edge from the specified source to the specified target, then this method does not change the graph and returnsfalse
. If the edge was added to the graph, returnstrue
.The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.
 Specified by:
addEdge
in interfaceGraph<V,E>
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge.e
 edge to be added to this graph. Returns:
true
if this graph did not already contain the specified edge. See Also:
Graph.addEdge(Object, Object)
,Graph.getEdgeSupplier()

addVertex
public V addVertex()
Description copied from interface:Graph
Creates a new vertex in this graph and returns it.This method creates the new vertex
v
using this graph's vertex supplier (seeGraph.getVertexSupplier()
). For the new vertex to be addedv
must not be equal to any other vertex in the graph. More formally, the graph must not contain any vertexv2
such thatv2.equals(v)
. If suchv2
is found then the newly created vertexv
is abandoned, the method leaves this graph unchanged and throws anIllegalArgumentException
.If the underlying graph implementation's
Graph.getVertexSupplier()
returnsnull
, then this method cannot create vertices and throws anUnsupportedOperationException
.Care must also be taken when interchanging calls to methods
Graph.addVertex(Object)
andGraph.addVertex()
. In such a case the user must make sure never to add vertices in the graph using methodGraph.addVertex(Object)
, which are going to be returned in the future by the supplied vertex supplier. Such a sequence will result into anIllegalArgumentException
when calling methodGraph.addVertex()
. Specified by:
addVertex
in interfaceGraph<V,E>
 Returns:
 The newly created vertex if added to the graph.
 See Also:
Graph.getVertexSupplier()

addVertex
public boolean addVertex(V v)
Adds the specified vertex to this graph if not already present. More formally, adds the specified vertex,v
, to this graph if this graph contains no vertexu
such thatu.equals(v)
. If this graph already contains such vertex, the call leaves this graph unchanged and returnsfalse
. In combination with the restriction on constructors, this ensures that graphs never contain duplicate vertices.

getEdgeSource
public V getEdgeSource(E e)
Returns the source vertex of an edge. For an undirected graph, source and target are distinguishable designations (but without any mathematical meaning). Specified by:
getEdgeSource
in interfaceGraph<V,E>
 Parameters:
e
 edge of interest Returns:
 source vertex

getEdgeTarget
public V getEdgeTarget(E e)
Returns the target vertex of an edge. For an undirected graph, source and target are distinguishable designations (but without any mathematical meaning). Specified by:
getEdgeTarget
in interfaceGraph<V,E>
 Parameters:
e
 edge of interest Returns:
 target vertex

clone
public java.lang.Object clone()
Returns a shallow copy of this graph instance. Neither edges nor vertices are cloned. Overrides:
clone
in classjava.lang.Object
 Returns:
 a shallow copy of this graph.
 Throws:
java.lang.RuntimeException
 in case the clone is not supported See Also:
Object.clone()

containsEdge
public boolean containsEdge(E e)
Returnstrue
if this graph contains the specified edge. More formally, returnstrue
if and only if this graph contains an edgee2
such thate.equals(e2)
. If the specified edge isnull
returnsfalse
. Specified by:
containsEdge
in interfaceGraph<V,E>
 Parameters:
e
 edge whose presence in this graph is to be tested. Returns:
true
if this graph contains the specified edge.

containsVertex
public boolean containsVertex(V v)
Returnstrue
if this graph contains the specified vertex. More formally, returnstrue
if and only if this graph contains a vertexu
such thatu.equals(v)
. If the specified vertex isnull
returnsfalse
. Specified by:
containsVertex
in interfaceGraph<V,E>
 Parameters:
v
 vertex whose presence in this graph is to be tested. Returns:
true
if this graph contains the specified vertex.

degreeOf
public int degreeOf(V vertex)
Returns the degree of the specified vertex.A degree of a vertex in an undirected graph is the number of edges touching that vertex. Edges with same source and target vertices (selfloops) are counted twice.
In directed graphs this method returns the sum of the "in degree" and the "out degree".

edgeSet
public java.util.Set<E> edgeSet()
Returns a set of the edges contained in this graph. The set is backed by the graph, so changes to the graph are reflected in the set. If the graph is modified while an iteration over the set is in progress, the results of the iteration are undefined.The graph implementation may maintain a particular set ordering (e.g. via
LinkedHashSet
) for deterministic iteration, but this is not required. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.

edgesOf
public java.util.Set<E> edgesOf(V vertex)
Returns a set of all edges touching the specified vertex. If no edges are touching the specified vertex returns an empty set.

inDegreeOf
public int inDegreeOf(V vertex)
Returns the "in degree" of the specified vertex.The "in degree" of a vertex in a directed graph is the number of inward directed edges from that vertex. See http://mathworld.wolfram.com/Indegree.html.
In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (selfloops) are counted twice.
 Specified by:
inDegreeOf
in interfaceGraph<V,E>
 Parameters:
vertex
 vertex whose degree is to be calculated. Returns:
 the degree of the specified vertex.

incomingEdgesOf
public java.util.Set<E> incomingEdgesOf(V vertex)
Returns a set of all edges incoming into the specified vertex.In the case of undirected graphs this method returns all edges touching the vertex, thus, some of the returned edges may have their source and target vertices in the opposite order.
 Specified by:
incomingEdgesOf
in interfaceGraph<V,E>
 Parameters:
vertex
 the vertex for which the list of incoming edges to be returned. Returns:
 a set of all edges incoming into the specified vertex.

outDegreeOf
public int outDegreeOf(V vertex)
Returns the "out degree" of the specified vertex.The "out degree" of a vertex in a directed graph is the number of outward directed edges from that vertex. See http://mathworld.wolfram.com/Outdegree.html.
In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (selfloops) are counted twice.
 Specified by:
outDegreeOf
in interfaceGraph<V,E>
 Parameters:
vertex
 vertex whose degree is to be calculated. Returns:
 the degree of the specified vertex.

outgoingEdgesOf
public java.util.Set<E> outgoingEdgesOf(V vertex)
Returns a set of all edges outgoing from the specified vertex.In the case of undirected graphs this method returns all edges touching the vertex, thus, some of the returned edges may have their source and target vertices in the opposite order.
 Specified by:
outgoingEdgesOf
in interfaceGraph<V,E>
 Parameters:
vertex
 the vertex for which the list of outgoing edges to be returned. Returns:
 a set of all edges outgoing from the specified vertex.

removeEdge
public E removeEdge(V sourceVertex, V targetVertex)
Removes an edge going from source vertex to target vertex, if such vertices and such edge exist in this graph. Returns the edge if removed ornull
otherwise. Specified by:
removeEdge
in interfaceGraph<V,E>
 Parameters:
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge. Returns:
 The removed edge, or
null
if no edge removed.

removeEdge
public boolean removeEdge(E e)
Removes the specified edge from the graph. Removes the specified edge from this graph if it is present. More formally, removes an edgee2
such thate2.equals(e)
, if the graph contains such edge. Returnstrue
if the graph contained the specified edge. (The graph will not contain the specified edge once the call returns).If the specified edge is
null
returnsfalse
. Specified by:
removeEdge
in interfaceGraph<V,E>
 Parameters:
e
 edge to be removed from this graph, if present. Returns:
true
if and only if the graph contained the specified edge.

removeVertex
public boolean removeVertex(V v)
Removes the specified vertex from this graph including all its touching edges if present. More formally, if the graph contains a vertexu
such thatu.equals(v)
, the call removes all edges that touchu
and then removesu
itself. If no suchu
is found, the call leaves the graph unchanged. Returnstrue
if the graph contained the specified vertex. (The graph will not contain the specified vertex once the call returns).If the specified vertex is
null
returnsfalse
. Specified by:
removeVertex
in interfaceGraph<V,E>
 Parameters:
v
 vertex to be removed from this graph, if present. Returns:
true
if the graph contained the specified vertex;false
otherwise.

vertexSet
public java.util.Set<V> vertexSet()
Returns a set of the vertices contained in this graph. The set is backed by the graph, so changes to the graph are reflected in the set. If the graph is modified while an iteration over the set is in progress, the results of the iteration are undefined.The graph implementation may maintain a particular set ordering (e.g. via
LinkedHashSet
) for deterministic iteration, but this is not required. It is the responsibility of callers who rely on this behavior to only use graph implementations which support it.

getEdgeWeight
public double getEdgeWeight(E e)
Returns the weight assigned to a given edge. Unweighted graphs return 1.0 (as defined byGraph.DEFAULT_EDGE_WEIGHT
), allowing weightedgraph algorithms to apply to them when meaningful. Specified by:
getEdgeWeight
in interfaceGraph<V,E>
 Parameters:
e
 edge of interest Returns:
 edge weight

setEdgeWeight
public void setEdgeWeight(E e, double weight)
Set an edge weight. Specified by:
setEdgeWeight
in interfaceGraph<V,E>
 Parameters:
e
 the edgeweight
 the weight Throws:
java.lang.UnsupportedOperationException
 if the graph is not weighted

getType
public GraphType getType()
Get the graph type. The graph type can be used to query for additional metadata such as whether the graph supports directed or undirected edges, selfloops, multiple (parallel) edges, weights, etc.

iterables
public GraphIterables<V,E> iterables()
Description copied from interface:Graph
Access the graph using theGraphIterables
interface. This allows accessing graphs without the restrictions imposed by 32bit arithmetic. Moreover, graph implementations are free to implement this interface without explicitly materializing intermediate results.

