org.jgrapht.graph.DefaultDirectedWeightedGraph Java Examples

/**
 * Use the jgrapht cycle checker to detect any cycles in the provided dependency graph.
 */
private void checkForCycles(DefaultDirectedWeightedGraph<RuleProvider, DefaultEdge> graph)
{
    CycleDetector<RuleProvider, DefaultEdge> cycleDetector = new CycleDetector<>(graph);

    if (cycleDetector.detectCycles())
    {
        // if we have cycles, then try to throw an exception with some usable data
        Set<RuleProvider> cycles = cycleDetector.findCycles();
        StringBuilder errorSB = new StringBuilder();
        for (RuleProvider cycle : cycles)
        {
            errorSB.append("Found dependency cycle involving: " + cycle.getMetadata().getID()).append(System.lineSeparator());
            Set<RuleProvider> subCycleSet = cycleDetector.findCyclesContainingVertex(cycle);
            for (RuleProvider subCycle : subCycleSet)
            {
                errorSB.append("\tSubcycle: " + subCycle.getMetadata().getID()).append(System.lineSeparator());
            }
        }
        throw new RuntimeException("Dependency cycles detected: " + errorSB.toString());
    }
}
 

private DefaultDirectedWeightedGraph<V, DefaultWeightedEdge> makeDirectedCopy(SimpleWeightedGraph<V, E> graph) {
    final DefaultDirectedWeightedGraph<V, DefaultWeightedEdge> copy = new DefaultDirectedWeightedGraph<>(DefaultWeightedEdge.class);

    Graphs.addAllVertices(copy, graph.vertexSet());
    graph.edgeSet().forEach((e) -> {
        V v1 = graph.getEdgeSource(e);
        V v2 = graph.getEdgeTarget(e);
        Graphs.addEdge(copy, v1, v2, graph.getEdgeWeight(e));
        Graphs.addEdge(copy, v2, v1, graph.getEdgeWeight(e));
    });
    
    return copy;
}
 

private void addExecuteBeforeRelationship(DefaultDirectedWeightedGraph<RuleProvider, DefaultEdge> graph, RuleProvider provider,
            List<String> errors, Class<? extends RuleProvider> clz)
{
    RuleProvider otherProvider = getByClass(clz);
    if (otherProvider == null)
    {
        errors.add("RuleProvider " + provider.getMetadata().getID() + " is specified to execute before: "
                    + clz.getName() + " but this class could not be found.");
    }
    else
        graph.addEdge(provider, otherProvider);
}
 

private void addExecuteAfterRelationship(DefaultDirectedWeightedGraph<RuleProvider, DefaultEdge> graph, RuleProvider provider,
            List<String> errors, Class<? extends RuleProvider> clz)
{
    RuleProvider otherProvider = getByClass(clz);
    if (otherProvider == null)
    {
        errors.add("RuleProvider " + provider.getMetadata().getID() + " is specified to execute after class: "
                    + clz.getName() + " but this class could not be found.");
    }
    else
        graph.addEdge(otherProvider, provider);
}
 

/**
 * Test if the graph is instance of <code>DefaultDirectedWeightedGraph</code> or
 * <code>DefaultUndirectedWeightedGraph</code>
 * 
 * @return <code>true</code> if the graph is a weighted graph
 */
public boolean isWeightedGraph() {
	return fData instanceof DefaultDirectedWeightedGraph || fData instanceof DefaultUndirectedWeightedGraph;
}