org.jgrapht.ext

Class GraphMLImporter<V,E>

java.lang.Object

org.jgrapht.ext.GraphMLImporter<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

GraphImporter<V,E>

public class GraphMLImporter<V,E>
extends Object
implements GraphImporter<V,E>

Imports a graph from a GraphML data source.

For a description of the format see http://en.wikipedia.org/wiki/ GraphML or the GraphML Primer.

Below is small example of a graph in GraphML format.

 
 <?xml version="1.0" encoding="UTF-8"?>
 <graphml xmlns="http://graphml.graphdrawing.org/xmlns"  
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns 
     http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd">
   <key id="d0" for="node" attr.name="color" attr.type="string">
     <default>yellow</default>
   </key>
   <key id="d1" for="edge" attr.name="weight" attr.type="double"/>
   <graph id="G" edgedefault="undirected">
     <node id="n0">
       <data key="d0">green</data>
     </node>
     <node id="n1"/>
     <node id="n2">
       <data key="d0">blue</data>
     </node>
     <node id="n3">
       <data key="d0">red</data>
     </node>
     <node id="n4"/>
     <node id="n5">
       <data key="d0">turquoise</data>
     </node>
     <edge id="e0" source="n0" target="n2">
       <data key="d1">1.0</data>
     </edge>
     <edge id="e1" source="n0" target="n1">
       <data key="d1">1.0</data>
     </edge>
     <edge id="e2" source="n1" target="n3">
       <data key="d1">2.0</data>
     </edge>
     <edge id="e3" source="n3" target="n2"/>
     <edge id="e4" source="n2" target="n4"/>
     <edge id="e5" source="n3" target="n5"/>
     <edge id="e6" source="n5" target="n4">
       <data key="d1">1.1</data>
     </edge>
   </graph>
 </graphml>
 
 

The importer reads the input into a graph which is provided by the user. In case the graph is an instance of WeightedGraph and the corresponding edge key with attr.name="weight" is defined, the importer also reads edge weights. Otherwise edge weights are ignored.

GraphML-Attributes Values are read as string key-value pairs and passed on to the VertexProvider and EdgeProvider respectively.

The provided graph object, where the imported graph will be stored, must be able to support the features of the graph that is read. For example if the GraphML file contains self-loops then the graph provided must also support self-loops. The same for multiple edges. Moreover, the parser completely ignores the attribute "edgedefault" which denotes whether an edge is directed or not. Whether edges are directed or not depends on the underlying implementation of the user provided graph object.

The importer validates the input using the 1.0 GraphML Schema.

Since:

July 2016

Author:

Dimitrios Michail

Constructor Summary

Constructors

Constructor and Description
GraphMLImporter(VertexProvider<V> vertexProvider, EdgeProvider<V,E> edgeProvider) Constructs a new importer.

Method Summary

Modifier and Type	Method and Description
EdgeProvider<V,E>	getEdgeProvider() Get the edge provider
String	getEdgeWeightAttributeName() Get the attribute name for edge weights
VertexProvider<V>	getVertexProvider() Get the vertex provider
void	importGraph(Graph<V,E> graph, Reader input) Import a graph.
void	setEdgeProvider(EdgeProvider<V,E> edgeProvider) Set the edge provider.
void	setEdgeWeightAttributeName(String edgeWeightAttributeName) Set the attribute name to use for edge weights.
void	setVertexProvider(VertexProvider<V> vertexProvider) Set the vertex provider

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.jgrapht.ext.GraphImporter

importGraph, importGraph

Constructor Detail

GraphMLImporter

public GraphMLImporter(VertexProvider<V> vertexProvider,
                       EdgeProvider<V,E> edgeProvider)

Constructs a new importer.

Parameters:

vertexProvider - provider for the generation of vertices. Must not be null.

edgeProvider - provider for the generation of edges. Must not be null.

Method Detail

getVertexProvider

public VertexProvider<V> getVertexProvider()

Get the vertex provider

Returns:

the vertex provider

setVertexProvider

public void setVertexProvider(VertexProvider<V> vertexProvider)

Set the vertex provider

Parameters:

vertexProvider - the new vertex provider. Must not be null.

getEdgeProvider

public EdgeProvider<V,E> getEdgeProvider()

Get the edge provider

Returns:

The edge provider

setEdgeProvider

public void setEdgeProvider(EdgeProvider<V,E> edgeProvider)

Set the edge provider.

Parameters:

edgeProvider - the new edge provider. Must not be null.

getEdgeWeightAttributeName

public String getEdgeWeightAttributeName()

Get the attribute name for edge weights

Returns:

the attribute name

setEdgeWeightAttributeName

public void setEdgeWeightAttributeName(String edgeWeightAttributeName)

Set the attribute name to use for edge weights.

Parameters:

edgeWeightAttributeName - the attribute name

importGraph

public void importGraph(Graph<V,E> graph,
                        Reader input)
                 throws ImportException

Import a graph.

The provided graph must be able to support the features of the graph that is read. For example if the GraphML file contains self-loops then the graph provided must also support self-loops. The same for multiple edges.

If the provided graph is a weighted graph, the importer also reads edge weights.

GraphML-Attributes Values are read as string key-value pairs and passed on to the VertexProvider and EdgeProvider respectively.

Specified by:

importGraph in interface GraphImporter<V,E>

Parameters:

graph - the output graph

input - the input reader

Throws:

ImportException - in case an error occurs, such as I/O or parse error