public void read(String filename) {
logger.info("read vrp from file " + filename);
XMLConfiguration xmlConfig = new XMLConfiguration();
xmlConfig.setFileName(filename);
xmlConfig.setAttributeSplittingDisabled(true);
xmlConfig.setDelimiterParsingDisabled(true);
if (schemaValidation) {
final InputStream resource = Resource.getAsInputStream("vrp_xml_schema.xsd");
if (resource != null) {
EntityResolver resolver =
new EntityResolver() {
@Override
public InputSource resolveEntity(String publicId, String systemId)
throws SAXException, IOException {
{
InputSource is = new InputSource(resource);
return is;
}
}
};
xmlConfig.setEntityResolver(resolver);
xmlConfig.setSchemaValidation(true);
logger.info("validating " + filename + " with xsd-schema");
} else {
logger.warn(
"cannot find schema-xsd file (vrp_xml_schema.xsd). try to read xml without xml-file-validation.");
}
}
try {
xmlConfig.load();
} catch (ConfigurationException e) {
logger.error(e);
e.printStackTrace();
System.exit(1);
}
readProblemType(xmlConfig);
readVehiclesAndTheirTypes(xmlConfig);
readShipments(xmlConfig);
readServices(xmlConfig);
readInitialRoutes(xmlConfig);
readSolutions(xmlConfig);
addJobsAndTheirLocationsToVrp();
}
@Override
public void informAlgorithmStarts(
VehicleRoutingProblem problem,
VehicleRoutingAlgorithm algorithm,
Collection<VehicleRoutingProblemSolution> solutions) {
logger.info("prepare schrimpfAcceptanceFunction, i.e. determine initial threshold");
double now = System.currentTimeMillis();
/*
* randomWalk to determine standardDev
*/
final double[] results = new double[nOfRandomWalks];
URL resource = Resource.getAsURL("randomWalk.xml");
AlgorithmConfig algorithmConfig = new AlgorithmConfig();
new AlgorithmConfigXmlReader(algorithmConfig).read(resource);
VehicleRoutingAlgorithm vra =
VehicleRoutingAlgorithms.createAlgorithm(problem, algorithmConfig);
vra.setMaxIterations(nOfRandomWalks);
vra.getAlgorithmListeners()
.addListener(
new IterationEndsListener() {
@Override
public void informIterationEnds(
int iteration,
VehicleRoutingProblem problem,
Collection<VehicleRoutingProblemSolution> solutions) {
double result = Solutions.bestOf(solutions).getCost();
// logger.info("result="+result);
results[iteration - 1] = result;
}
});
vra.searchSolutions();
StandardDeviation dev = new StandardDeviation();
double standardDeviation = dev.evaluate(results);
double initialThreshold = standardDeviation / 2;
schrimpfAcceptance.setInitialThreshold(initialThreshold);
logger.info("took " + ((System.currentTimeMillis() - now) / 1000.0) + " seconds");
logger.debug("initial threshold: " + initialThreshold);
logger.info("---------------------------------------------------------------------");
}