Module org.jgrapht.io
Package org.jgrapht.nio.graphml

Class SimpleGraphMLEventDrivenImporter

java.lang.Object
org.jgrapht.nio.BaseEventDrivenImporter<String,Triple<String,String,Double>>
org.jgrapht.nio.graphml.SimpleGraphMLEventDrivenImporter
All Implemented Interfaces:
EventDrivenImporter<String,Triple<String,String,Double>>
public class SimpleGraphMLEventDrivenImporter extends BaseEventDrivenImporter<String,Triple<String,String,Double>> implements EventDrivenImporter<String,Triple<String,String,Double>>
Imports a graph from a GraphML data source. The importer does not construct a graph but calls the provided consumers with the appropriate arguments. Vertices are returned simply by their vertex id and edges are returns as triples (source, target, weight) where weight maybe null.

The importer notifies lazily and completely out-of-order for any additional vertex, edge or graph attributes in the input file. Users can register consumers for vertex, edge and graph attributes after construction of the importer. Finally, default attribute values are completely ignored. Lazily here means that an edge is first reported with a null weight and its weight is reported later using the edge attribute consumer. Since the same triple instance is used in all cases, an edge may appear having a null weight when it is first reported and having a non-null weight after the edge weight is reported.

This is a simple implementation with supports only a limited set of features of the GraphML specification. For a more rigorous parser use GraphMLImporter. This version is oriented towards parsing speed.

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" />
   <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">
       <data key="d0">black</data>
     </node>     
     <node id="n2">
       <data key="d0">blue</data>
     </node>
     <node id="n3">
       <data key="d0">red</data>
     </node>
     <node id="n4">
       <data key="d0">white</data>
     </node>
     <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 by default validates the input using the 1.0 GraphML Schema. The user can (not recommended) disable the validation by calling setSchemaValidation(boolean).

Author:
Dimitrios Michail

  • Constructor Details

    • SimpleGraphMLEventDrivenImporter

      public SimpleGraphMLEventDrivenImporter()
      Constructs a new importer.

  • Method Details

    • 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

    • isSchemaValidation

      public boolean isSchemaValidation()
      Whether the importer validates the input
      Returns:
      true if the importer validates the input

    • setSchemaValidation

      public void setSchemaValidation(boolean schemaValidation)
      Set whether the importer should validate the input
      Parameters:
      schemaValidation - value for schema validation

    • importInput

      public void importInput(Reader input)
      Description copied from interface: EventDrivenImporter
      Import a graph
      Specified by:
      importInput in interface EventDrivenImporter<String,Triple<String,String,Double>>
      Parameters:
      input - the input reader