I am a new Repast user, could you please help me fixing this error: I have a run time error as you can see below. When i commenting the addEdge command, the program runs well net. <<< addEdge (this , zombie ); >>>
Please note that my code is exactly the same like the tutorial.
The error i have as follows:
FATAL [Thread-7] 14:34:36,287 repast.simphony.ui.GUIScheduleRunner - RunTimeException when running the schedule
Current tick (14.0)
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at repast.simphony.engine.schedule.DynamicTargetAction.execute(DynamicTargetAction.java:72)
at repast.simphony.engine.controller.ScheduledMethodControllerAction$ScheduleMethodAllAction.execute(ScheduledMethodControllerAction.java:333)
at repast.simphony.engine.schedule.DefaultAction.execute(DefaultAction.java:38)
at repast.simphony.engine.schedule.ScheduleGroup.executeList(ScheduleGroup.java:205)
at repast.simphony.engine.schedule.ScheduleGroup.execute(ScheduleGroup.java:231)
at repast.simphony.engine.schedule.Schedule.execute(Schedule.java:352)
at repast.simphony.ui.GUIScheduleRunner$ScheduleLoopRunnable.run(GUIScheduleRunner.java:52)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
at jzombies.Zombie$$FastClassByCGLIB$$6141f31.invoke(<generated>)
at net.sf.cglib.reflect.FastMethod.invoke(FastMethod.java:53)
at repast.simphony.engine.schedule.DynamicTargetAction.execute(DynamicTargetAction.java:69)
... 7 more
Caused by: java.lang.NullPointerException
at jzombies.Zombie.infect(Zombie.java:106)
at jzombies.Zombie.step(Zombie.java:60)
... 10 moreThe following is my classes:
Zombies:
package jzombies;
import java.util.ArrayList;
import java.util.List;
import repast.simphony.context.Context;
import repast.simphony.engine.schedule.ScheduledMethod;
import repast.simphony.query.space.grid.GridCell;
import repast.simphony.query.space.grid.GridCellNgh;
import repast.simphony.random.RandomHelper;
import repast.simphony.space.SpatialMath;
import repast.simphony.space.continuous.ContinuousSpace;
import repast.simphony.space.continuous.NdPoint;
import repast.simphony.space.graph.Network;
import repast.simphony.space.grid.Grid;
import repast.simphony.space.grid.GridPoint;
import repast.simphony.util.ContextUtils;
import repast.simphony.util.SimUtilities;
/**
* @author gamal91
*
*/
public class Zombie {
private ContinuousSpace<Object> space;
private Grid<Object> grid;
private boolean moved;
public Zombie(ContinuousSpace<Object> space, Grid<Object> grid) {
this.space = space;
this.grid = grid;
}
// (Annotation) To iterate each time step.
@ScheduledMethod (start = 1 ,interval = 1)
public void step() {
// Get the grid location of this Zombie.
GridPoint pt = grid.getLocation(this);
GridCellNgh<Human> nghCreator = new GridCellNgh<Human>(grid, pt, Human.class, 1, 1);
List<GridCell<Human>> gridCells = nghCreator.getNeighborhood(true);
SimUtilities.shuffle(gridCells, RandomHelper.getUniform());
GridPoint pointWithMostHumans = null;
int maxCount = -1;
for (GridCell<Human> cell : gridCells) {
if (cell.size() > maxCount) {
pointWithMostHumans = cell.getPoint();
maxCount = cell.size();
}
}
moveTowards(pointWithMostHumans);
infect();
}
public void moveTowards(GridPoint pt) {
if (!pt.equals(grid.getLocation(this))) {
NdPoint myPoint = space.getLocation(this);
NdPoint otherPoint = new NdPoint(pt.getX(), pt.getY());
double angle = SpatialMath.calcAngleFor2DMovement(space, myPoint, otherPoint);
// You may delete the zero and see what will happen
space.moveByVector(this, 1, angle, 0);
myPoint = space.getLocation(this);
grid.moveTo(this, (int) myPoint.getX(), (int) myPoint.getY());
moved = true;
}
}
@SuppressWarnings("unchecked")
public void infect() {
GridPoint pt = grid.getLocation(this);
List<Object> humans = new ArrayList<Object>();
for (Object obj : grid.getObjectsAt(pt.getX(), pt.getY())) {
if (obj instanceof Human) {
humans.add(obj);
}
}
if (humans.size() > 0) {
int index = RandomHelper.nextIntFromTo(0, humans.size() - 1);
Object obj = humans.get(index);
NdPoint spacePt = space.getLocation(obj);
Context<Object> context = ContextUtils.getContext(obj);
context.remove(obj);
Zombie zombie = new Zombie(space, grid);
context.add(zombie);
space.moveTo(zombie, spacePt.getX(), spacePt.getY());
grid.moveTo(zombie, pt.getX(), pt.getY());
Network<Object> net = (Network<Object>) context.getProjection("infection netwrok");
net.addEdge(this, zombie);
}
}
}Humans Class
package jzombies;
import java.util.List;
import repast.simphony.engine.watcher.Watch;
import repast.simphony.engine.watcher.WatcherTriggerSchedule;
import repast.simphony.query.space.grid.GridCell;
import repast.simphony.query.space.grid.GridCellNgh;
import repast.simphony.random.RandomHelper;
import repast.simphony.space.SpatialMath;
import repast.simphony.space.continuous.ContinuousSpace;
import repast.simphony.space.continuous.NdPoint;
import repast.simphony.space.grid.Grid;
import repast.simphony.space.grid.GridPoint;
import repast.simphony.util.SimUtilities;
/**
* @author gamal91
*
*/
public class Human {
private ContinuousSpace<Object> space;
private Grid<Object> grid;
private int energy, startingEnergy;
public Human(ContinuousSpace<Object> space, Grid<Object> grid, int energy) {
this.space = space;
this.grid = grid;
this.energy = startingEnergy = energy;
}
@Watch (watcheeClassName = "jzombies.Zombie" ,
watcheeFieldNames = "moved",
query = "within_moore 1",
whenToTrigger = WatcherTriggerSchedule.IMMEDIATE)
public void run() {
GridPoint pt = grid.getLocation(this);
GridCellNgh<Zombie> nghCreator = new GridCellNgh<Zombie>(grid, pt, Zombie.class, 1, 1);
List<GridCell<Zombie>> gridCells = nghCreator.getNeighborhood(true);
SimUtilities.shuffle(gridCells, RandomHelper.getUniform());
GridPoint pointWithLeastZombies = null;
int minCount = Integer.MAX_VALUE;
for (GridCell<Zombie> cell : gridCells) {
if (cell.size() < minCount) {
pointWithLeastZombies = cell.getPoint();
minCount = cell.size();
}
}
if (energy > 0) {
moveTowards(pointWithLeastZombies);
} else {
energy = startingEnergy;
}
}
public void moveTowards(GridPoint pt) {
if (!pt.equals(grid.getLocation(this))) {
NdPoint myPoint = space.getLocation(this);
NdPoint otherPoint = new NdPoint(pt.getX(), pt.getY());
double angle = SpatialMath.calcAngleFor2DMovement(space, myPoint, otherPoint);
// Moves it two units along the calculated angel.
space.moveByVector(this, 2, angle, 0);
myPoint = space.getLocation(this);
grid.moveTo(this, (int) myPoint.getX(), (int) myPoint.getY());
energy--;
}
}
}jZobies Class :
package jzombies;
// import repast.simphony.engine.environment.RunEnvironment;
// import repast.simphony.context.DefaultContext;
import repast.simphony.context.Context;
import repast.simphony.context.space.continuous.ContinuousSpaceFactory;
import repast.simphony.context.space.continuous.ContinuousSpaceFactoryFinder;
import repast.simphony.context.space.graph.NetworkBuilder;
import repast.simphony.context.space.grid.GridFactory;
import repast.simphony.context.space.grid.GridFactoryFinder;
import repast.simphony.dataLoader.ContextBuilder;
import repast.simphony.random.RandomHelper;
import repast.simphony.space.continuous.ContinuousSpace;
import repast.simphony.space.continuous.NdPoint;
import repast.simphony.space.continuous.RandomCartesianAdder;
import repast.simphony.space.grid.Grid;
import repast.simphony.space.grid.GridBuilderParameters;
import repast.simphony.space.grid.SimpleGridAdder;
import repast.simphony.space.grid.WrapAroundBorders;
public class JZobieBuilder implements ContextBuilder<Object> {
@Override
public Context build(Context<Object> context) {
// Should match the project name
context.setId("jzombies");
NetworkBuilder<Object> netBuilder = new NetworkBuilder<Object>("infection network", context, true);
netBuilder.buildNetwork();
ContinuousSpaceFactory spaceFactory = ContinuousSpaceFactoryFinder.createContinuousSpaceFactory(null);
ContinuousSpace<Object> space = spaceFactory.createContinuousSpace("space", context,
// Anything is added to this space will be randomly located.
new RandomCartesianAdder<Object>(), new repast.simphony.space.continuous.WrapAroundBorders(), 50, 50);
GridFactory gridFactory = GridFactoryFinder.createGridFactory(null);
Grid<Object> grid = gridFactory.createGrid("grid", context, new GridBuilderParameters<Object>(
// More than one obejct are allowed to occupy a grid point.
new WrapAroundBorders(), new SimpleGridAdder<Object>(), true, 50, 50));
int zombieCount = 20;
for (int i = 0; i < zombieCount; i++) {
context.add(new Zombie(space, grid));
}
int humanCount = 100;
for (int i = 0; i < humanCount; i++) {
int energy = RandomHelper.nextIntFromTo(4, 10);
context.add(new Human(space, grid, energy));
}
for (Object obj : context) {
NdPoint pt = space.getLocation(obj);
grid.moveTo(obj, (int) pt.getX(), (int) pt.getY());
}
return context;
}
}
