java.lang.InstantiationException usign jGraph when trying to display the Weight of a lable

java.lang.InstantiationException usign jGraph when trying to display the
Weight of a lable

Hi everyone I'm tring to display a graph using jGraph. Instead of labling
an edge with the name of the source and target notes I want to display the
weight of the edge. For that, I created an aditional class to overwrite
the toString method of DefaultWeightedEdge this way
class MyWeightedEdge extends DefaultWeightedEdge {
@Override
public String toString() {
return Double.toString(getWeight());
}
}
and instead of using DefaultWeightedEdge I use MyWeightedEdge everywhere,
but I'm getting a java.lang.InstantiationException
Exception in thread "main" java.lang.RuntimeException: Edge factory failed
at
org.jgrapht.graph.ClassBasedEdgeFactory.createEdge(ClassBasedEdgeFactory.java:86)
at
org.jgrapht.ext.JGraphModelAdapter$ShieldedGraph.addEdge(JGraphModelAdapter.java:1091)
at
org.jgrapht.ext.JGraphModelAdapter.handleJGraphInsertedEdge(JGraphModelAdapter.java:506)
at
org.jgrapht.ext.JGraphModelAdapter.handleJGraphChangedEdge(JGraphModelAdapter.java:474)
at
org.jgrapht.ext.JGraphModelAdapter$JGraphListener.handleChangedEdges(JGraphModelAdapter.java:964)
at
org.jgrapht.ext.JGraphModelAdapter$JGraphListener.graphChanged(JGraphModelAdapter.java:893)
at org.jgraph.graph.DefaultGraphModel.fireGraphChanged(Unknown Source)
at org.jgraph.graph.DefaultGraphModel$GraphModelEdit.execute(Unknown Source)
at org.jgraph.graph.DefaultGraphModel.insert(Unknown Source)
at
org.jgrapht.ext.JGraphModelAdapter.internalInsertCell(JGraphModelAdapter.java:769)
at
org.jgrapht.ext.JGraphModelAdapter.handleJGraphTAddedEdge(JGraphModelAdapter.java:651)
at
org.jgrapht.ext.JGraphModelAdapter$JGraphTListener.edgeAdded(JGraphModelAdapter.java:1036)
at
org.jgrapht.graph.DefaultListenableGraph.fireEdgeAdded(DefaultListenableGraph.java:317)
at
org.jgrapht.graph.DefaultListenableGraph.addEdge(DefaultListenableGraph.java:182)
at Visual.JGraphAdapterDemo.init(JGraphAdapterDemo.java:135)
at Visual.JGraphAdapterDemo.<init>(JGraphAdapterDemo.java:89)
at world.Conection.paint(Conection.java:268)
at world.Conection.<init>(Conection.java:56)
at world.Conection.main(Conection.java:44)
Caused by: java.lang.InstantiationException:
Visual.JGraphAdapterDemo$MyWeightedEdge
at java.lang.Class.newInstance(Unknown Source)
at
org.jgrapht.graph.ClassBasedEdgeFactory.createEdge(ClassBasedEdgeFactory.java:84)
... 18 more
If somebody knows how can I fix this will help me a lot.
Thanks,