Defining and Throwing Exceptions

Defining UnchartedTerritoryException

The file UnchartedTerritoryException.java:

package territory;                                                              

/**
 * Thrown when the Location of a Wanderer object in a Territory is outside the
 * boundaries of the Territory.
 **/
public class UnchartedTerritoryException extends RuntimeException {

    public UnchartedTerritoryException(int x, int y) {
        System.out.println("Invalid coordinates " + x + ", " + y);
    }
}

Throwing an UnchartedTerritoryException

From the drawWanderer method in Territory.java

if ((posX < 0 || posX >= TERRITORY_WIDTH) ||
    (posY < 0 || posY >= TERRITORY_HEIGHT)) {
	// ... graphics code omitted ...
	// draw a dead wanderer and throw exception                                         
	// ... more graphics code omitted ...
	throw new UnchartedTerritoryException(posX, posY);
}