Module com.github.moaxcp.graphs.core

Package com.github.moaxcp.graphs

Interface Graph<ID>

Type Parameters:

ID - type of all identifiers in graph

All Known Subinterfaces:

EventGraph<ID>

All Known Implementing Classes:

AbstractGraph, DirectedGraph, UndirectedGraph

public interface Graph<ID>

A graph is composed of vertices and edges. A vertex is able to connect to other vertices through edges. Edges connect two vertices. A graph can be directed or undirected.

Vertices have an 'id' which uniquely identifies the vertex within the graph. Edges have a 'to' and 'from' property which are the ids of the vertex endpoints. Edges are optionally identified.

At all times the graph is valid event when removing connected vertices.

Undirected graphs ignore 'from'/'to' order in edges.

Once a vertex or edge is removed it can no longer modify the graph or be modified.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	Graph.Edge<ID>	An edge between two vertices in a graph.
static interface	Graph.Vertex<ID>	Vertex of graph.

Method Summary

Modifier and Type	Method	Description
Graph.Edge<ID>	edge(ID from, ID to)	Ensures an edge exists between 'from' and 'to' vertices.
Graph<ID>	edgeProperty(String name, Object value)	Sets edge property returning this graph
Optional<Graph.Edge<ID>>	findEdge(ID id)	finds edge with given id.
Optional<Graph.Edge<ID>>	findEdge(ID from, ID to)	Finds edge connecting 'from' and 'to' vertex.
Optional<Graph.Vertex<ID>>	findVertex(ID id)	Finds vertex with given id.
Map<ID,Graph.Edge<ID>>	getEdgeIds()	Returns a map of edge ids to edges.
Map<String,Object>	getEdgeProperties()	Returns an unmodifiable map of edge properties.
Optional<Object>	getEdgeProperty(String name)	Returns Optional of an edge property.
Collection<Graph.Edge<ID>>	getEdges()	Returns an ordered collection of all edges in this graph.
Optional<ID>	getId()	Returns the id of this graph.
Map<String,Object>	getProperties()	Returns an unmodifiable map of properties for this graph.
Optional<Object>	getProperty(String name)	Returns Optional of a property.
Map<String,Object>	getVertexProperties()	Retruns an unmodifiable map of vertex properties.
Optional<Object>	getVertexProperty(String name)	Returns Optional of a vertex property.
Map<ID,Graph.Vertex<ID>>	getVertices()	Returns an ordered map of all vertices in this graph.
Graph<ID>	id(ID id)	Sets the id of this graph
boolean	isDirected()	Returns true if this graph is directed.
Graph<ID>	property(String name, Object value)	Sets property on this graph returning this graph
void	removeEdge(ID id)	Removes edge with given id
void	removeEdge(ID from, ID to)	Removes edge with given from and to.
Graph<ID>	removeEdgeProperty(String name)	Removes edge property returning this graph
Graph<ID>	removeProperty(String name)	Removes property on this graph returning this graph
void	removeVertex(ID id)	Removes vertex with given id.
Graph<ID>	removeVertexProperty(String name)	Removes vertex property returning this graph
void	setEdgeProperty(String name, Object value)	Sets edge property.
void	setId(ID id)	Sets the id of this graph.
void	setProperty(String name, Object value)	Sets property on this graph
void	setVertexProperty(String name, Object value)	Sets vertex property.
Graph.Vertex<ID>	vertex(ID id)	Ensure a vertex exists with id and returns the vertex.
Graph<ID>	vertexProperty(String name, Object value)	Sets vertex property returning this graph

Method Detail

getVertices

Map<ID,Graph.Vertex<ID>> getVertices()

Returns an ordered map of all vertices in this graph. The key is the vertex id. Ordering is determined by implementing class.

Returns:

ordered map of all vertices in this graph

getEdges

Collection<Graph.Edge<ID>> getEdges()

Returns an ordered collection of all edges in this graph.

Returns:

ordered collection of all edges

getEdgeIds

Map<ID,Graph.Edge<ID>> getEdgeIds()

Returns a map of edge ids to edges.

Returns:

map of edge ids to edges

findVertex

Optional<Graph.Vertex<ID>> findVertex(ID id)

Finds vertex with given id. If vertex is not in this graph the optional is empty.

Parameters:

id - of vertex

Returns:

optional of vertex

Throws:

NullPointerException - if id is null

vertex

Graph.Vertex<ID> vertex(ID id)

Ensure a vertex exists with id and returns the vertex. If the vertex does not exist it is created.

Parameters:

id - of vertex

Returns:

created or existing vertex

Throws:

NullPointerException - if id is null

removeVertex

void removeVertex(ID id)

Removes vertex with given id. If edges connect to the vertex they are removed first.

Parameters:

id - of vertex

Throws:

NullPointerException - if id is null

findEdge

Optional<Graph.Edge<ID>> findEdge(ID from,
                                  ID to)

Finds edge connecting 'from' and 'to' vertex. If edge is not in this graph the optional is empty. The order of 'from' and 'to' does not matter in undirected implementations. However, if the graph is directed 'from' and 'to' must match 'from' and 'to' of the edge exactly.

Parameters:

from - of edge

to - of edge

Returns:

optional of edge

Throws:

NullPointerException - if from or to is null

findEdge

Optional<Graph.Edge<ID>> findEdge(ID id)

finds edge with given id. If edge is not in this graph the optional is empty.

Parameters:

id - of edge

Returns:

optional of edge

Throws:

NullPointerException - if id is null

edge

Graph.Edge<ID> edge(ID from,
                    ID to)

Ensures an edge exists between 'from' and 'to' vertices. If an edge does not exist it is created. If any of the vertices do not exist they are created.

If this graph is undirected and contains an edge connecting 'to' and 'from' the edge will not be created. Undirected graphs ignore 'from'/'to' order in edges.

Parameters:

from - of edge

to - of edge

Returns:

created or existing edge

removeEdge

void removeEdge(ID from,
                ID to)

Removes edge with given from and to.

Parameters:

from - of edge

to - of edge

Throws:

NullPointerException - if from or to is null

IllegalArgumentException - if edge does not exist

removeEdge

void removeEdge(ID id)

Removes edge with given id

Parameters:

id - of edge

Throws:

NullPointerException - if id is null

IllegalArgumentException - if edge with id does not exist

getId

Optional<ID> getId()

Returns the id of this graph. If the id is not set and empty optional is returned.

Returns:

optional of id

setId

void setId(ID id)

Sets the id of this graph.

Parameters:

id - of graph

Throws:

NullPointerException - if id is null

id

Graph<ID> id(ID id)

Sets the id of this graph

Parameters:

id - of graph

Returns:

this graph

Throws:

NullPointerException - if id is null

isDirected

boolean isDirected()

Returns true if this graph is directed.

Returns:

if this graph is directed

getProperties

Map<String,Object> getProperties()

Returns an unmodifiable map of properties for this graph.

Returns:

an unmodifiable map of properties for this graph

getProperty

Optional<Object> getProperty(String name)

Returns Optional of a property. If the property does not exist the returned Optional is empty.

Parameters:

name - of property

Returns:

optional of named proeprty

Throws:

NullPointerException - if name is null

setProperty

void setProperty(String name,
                 Object value)

Sets property on this graph

Parameters:

name - of property

value - of property

Throws:

NullPointerException - if name or value is null

property

Graph<ID> property(String name,
                   Object value)

Sets property on this graph returning this graph

Parameters:

name - of property

value - of property

Returns:

this graph

Throws:

NullPointerException - if name or value is null

removeProperty

Graph<ID> removeProperty(String name)

Removes property on this graph returning this graph

Parameters:

name - of property

Returns:

this graph

Throws:

NullPointerException - if name is null

getEdgeProperties

Map<String,Object> getEdgeProperties()

Returns an unmodifiable map of edge properties.

Returns:

an unmodifiable map of edge properties

getEdgeProperty

Optional<Object> getEdgeProperty(String name)

Returns Optional of an edge property. If the property does not exist the returned Optional is empty.

Parameters:

name - of property

Returns:

optional of property

Throws:

NullPointerException - if name is null

setEdgeProperty

void setEdgeProperty(String name,
                     Object value)

Sets edge property.

Parameters:

name - of property

value - of property

Throws:

NullPointerException - if name or value is null

edgeProperty

Graph<ID> edgeProperty(String name,
                       Object value)

Sets edge property returning this graph

Parameters:

name - of edge property

value - of edge property

Returns:

this graph

Throws:

NullPointerException - if name or value is null

removeEdgeProperty

Graph<ID> removeEdgeProperty(String name)

Removes edge property returning this graph

Parameters:

name - of property

Returns:

this graph

Throws:

NullPointerException - if name is null

getVertexProperties

Map<String,Object> getVertexProperties()

Retruns an unmodifiable map of vertex properties.

Returns:

an unmodifiable map of vertex properties

getVertexProperty

Optional<Object> getVertexProperty(String name)

Returns Optional of a vertex property. If the property does not exist the returned Optional is empty.

Parameters:

name - of property

Returns:

optional of property

Throws:

NullPointerException - if name is null

setVertexProperty

void setVertexProperty(String name,
                       Object value)

Sets vertex property.

Parameters:

name - of property

value - of property

Throws:

NullPointerException - if name or value is null

vertexProperty

Graph<ID> vertexProperty(String name,
                         Object value)

Sets vertex property returning this graph

Parameters:

name - of property

value - of property

Returns:

created or existing edge

Throws:

NullPointerException - if name or value is null

removeVertexProperty

Graph<ID> removeVertexProperty(String name)

Removes vertex property returning this graph

Parameters:

name - of property

Returns:

this graph

Throws:

NullPointerException - if name is null