optaplanner - Vehicle Routing with multiple locations per customer -

i'm trying solve vehicle routing each customer has multiple locations, of 1 needs visited. obtained optaplanner-master , modified vehiclerouting example in following manner:

customer.java:

/*  * copyright 2012 red hat, inc. and/or affiliates.  *  * licensed under apache license, version 2.0 (the "license");  * may not use file except in compliance license.  * may obtain copy of license @  *  *      http://www.apache.org/licenses/license-2.0  *  * unless required applicable law or agreed in writing, software  * distributed under license distributed on "as is" basis,  * without warranties or conditions of kind, either express or implied.  * see license specific language governing permissions ,  * limitations under license.  */  package org.optaplanner.examples.vehiclerouting.domain;  import com.thoughtworks.xstream.annotations.xstreamalias; import com.thoughtworks.xstream.annotations.xstreaminclude; import org.optaplanner.core.api.domain.entity.planningentity; import org.optaplanner.core.api.domain.valuerange.countablevaluerange; import org.optaplanner.core.api.domain.valuerange.valuerangefactory; import org.optaplanner.core.api.domain.valuerange.valuerangeprovider; import org.optaplanner.core.api.domain.variable.anchorshadowvariable; import org.optaplanner.core.api.domain.variable.planningvariable; import org.optaplanner.core.api.domain.variable.planningvariablegraphtype; import org.optaplanner.examples.common.domain.abstractpersistable; import org.optaplanner.examples.vehiclerouting.domain.location.location; import org.optaplanner.examples.vehiclerouting.domain.solver.depotanglecustomerdifficultyweightfactory; import org.optaplanner.examples.vehiclerouting.domain.timewindowed.timewindowedcustomer;  import java.util.list;  @planningentity(difficultyweightfactoryclass = depotanglecustomerdifficultyweightfactory.class) @xstreamalias("vrpcustomer") @xstreaminclude({         timewindowedcustomer.class }) public class customer extends abstractpersistable implements standstill {      protected int demand;      // planning variables: changes during planning, between score calculations.     protected standstill previousstandstill;      // shadow variables     protected customer nextcustomer;     protected vehicle vehicle;      protected list<location> locations;     protected integer selectedlocation = 0;      public void setselectedlocation(integer selectedlocation){         this.selectedlocation = selectedlocation;     }      @planningvariable(valuerangeproviderrefs = {"selectedlocation"})     public integer getselectedlocation(){         return selectedlocation;     }      @valuerangeprovider(id = "selectedlocation")     public countablevaluerange<integer> getselectablelocations(){         return valuerangefactory.createintvaluerange(0, locations.size());     }      public void setlocations(list<location> locations) {         this.locations = locations;     }      public list<location> getlocations(){         return locations;     }      @override     public location getlocation() {         return locations.get(selectedlocation);     }      @override     public string tostring() {         return "customer " + getid();     }       public int getdemand() {         return demand;     }      public void setdemand(int demand) {         this.demand = demand;     }      @planningvariable(valuerangeproviderrefs = {"vehiclerange", "customerrange"},             graphtype = planningvariablegraphtype.chained)     public standstill getpreviousstandstill() {         return previousstandstill;     }      public void setpreviousstandstill(standstill previousstandstill) {         this.previousstandstill = previousstandstill;     }      @override     public customer getnextcustomer() {         return nextcustomer;     }      @override     public void setnextcustomer(customer nextcustomer) {         this.nextcustomer = nextcustomer;     }      @override     @anchorshadowvariable(sourcevariablename = "previousstandstill")     public vehicle getvehicle() {         return vehicle;     }      public void setvehicle(vehicle vehicle) {         this.vehicle = vehicle;     }      // ************************************************************************     // complex methods     // ************************************************************************      /**      * @return positive number, distance multiplied 1000 avoid floating point arithmetic rounding errors      */     public long getdistancefrompreviousstandstill() {         if (previousstandstill == null) {             throw new illegalstateexception("this method must not called when previousstandstill ("                     + previousstandstill + ") not initialized yet.");         }         return getdistancefrom(previousstandstill);     }      /**      * @param standstill never null      * @return positive number, distance multiplied 1000 avoid floating point arithmetic rounding errors      */     public long getdistancefrom(standstill standstill) {         return standstill.getlocation().getdistanceto(getlocation());     }      /**      * @param standstill never null      * @return positive number, distance multiplied 1000 avoid floating point arithmetic rounding errors      */     public long getdistanceto(standstill standstill) {         return getlocation().getdistanceto(standstill.getlocation());     }   } 

in vehicleroutingimporter.java, code reads customer's location has changed to:

list<location> locations = new arraylist<>(linetokens.length-2); (int j = 2; j < linetokens.length; ++j){     long locationid = long.parselong(linetokens[j]);     location location = locationmap.get(locationid);     if (location == null)         throw new illegalargumentexception("missing location (id=" + locationid + ") specified customer id=" + id);         locations.add(location) } customer.setlocations(locations); 

all other code used call customer.setlocation(location) calls customer.setlocations(collections.singletonlist(location)). don't think of gets called.

in vehicleroutingsolverconfig.xml, removed these lines (otherwise, complains multiple variables):

  <subchainchangemoveselector>     <selectreversingmovetoo>true</selectreversingmovetoo>   </subchainchangemoveselector>   <subchainswapmoveselector>     <selectreversingmovetoo>true</selectreversingmovetoo>   </subchainswapmoveselector> 

tutorial-01-uncapacitated.vrp now:

name : tutorial-01-uncapacitated comment : geoffrey de smet - optaplanner vrp demo 01 type : cvrp dimension : 8 edge_weight_type : euc_2d  capacity : 100 node_coord_section   1 50 50  2 45 100  3 30 80  4 70 85  5 60 60  6 35 10  7 30 30  8 45 20 demand_section 1 0 2 1 2 3 3 1 3 4 4 1 4 5 5 1 5 6 6 1 6 7 7 1 7 8 8 1 8 2 depot_section  1    -1   vehicles : 2 eof 

it appears work, , finds optimal solution in small test cases (and, looks reasonable solution in large cases). when set fast_assert mode, fails following error:

caused by: java.lang.illegalstateexception: impossible variablelistener corruption: expectedworkingscore (0hard/-30000soft) not workingscore (0hard/-34142soft) after variablelisteners triggered without changes genuine variables. shadow variable values still same, impossible.