Using GraphStream as a file-format converter

[Geofrey Sanders <gsanders AT idfbins.com>]

Hello! I am looking for an hint to what I’m doing wrong with the GraphStream library; I want to use it to convert a Graphviz file (with FileSourceDOT) to a GraphML file (with FileSinkGML).

 

Having set up infile and outfile as the names of the input and output,

 

> FileSourceDOT reader = new FileSourceDOT();

> FileSinkGML writer = new FileSinkGML();

> Graph graph = new MultiGraph("graph", true, false);

>

> reader.addSink(graph);

> reader.readAll(infile); // IdAlreadyInUseException here

> writer.writeAll(graph, outfile);

 

I get an exception thrown from the readAll method:

 

Exception in thread "main" org.graphstream.graph.IdAlreadyInUseException: singleton exception: id 'ICD9Code' already used, cannot add node

                at org.graphstream.graph.implementations.DefaultGraph.addNode_(DefaultGraph.java:426)

                …

                at com.idfbins.gsanders.dot2gml.Main.main(Main.java:26)

 

The exception mentions the same id, “ICD9Code”, on every run. This makes me think I’m missing an initialization step or using the wrong kind of Graph object.

So far I can’t see what to change, so any suggestions are welcome!

 

-gws