Questão de Engenharia e Arquitetura

Suponha que as classes Circulo, Desenho e Figura ocupem arquivos separados. Em qual código Java elas serão compiladas sem erros? (A) package P1; import P2.*; public class Figura { protected double x,y; protected final double PI=0; Desenho d; abstract protected double dist(double x1,double y1); } package P1; public class Circulo extends Figura { double r; public Circulo() { d.add(this); PI=3.14159; } public double raio() { return r; } public double centroX() { return x; } public double centroY() { return y; } protected double dist(double x1,double y1) { return Math.sqrt((x1-x)*(x1-x)+(y1-y)*(y1-y)); } } package P2; import java.util.List; import P1.Figura; public class Desenho { List<Figura> f; public void add(Figura p) { f.add(p); } } 8 (B) package P1; import P2.*; abstract public class Figura { protected double x,y; protected final double PI=0; Desenho d; abstract protected double dist(double x1,double y1); } package P1; public class Circulo extends Figura { double r; public Circulo() { d.add(this); PI=3.14159; } public double raio() { return r; } public double centroX() { return x; } public double centroY() { return y; } private double dist(double x1,double y1) { return Math.sqrt((x1-x)*(x1-x)+(y1-y)*(y1-y)); } } package P2; import java.util.List; import P1.Figura; public class Desenho { List<Figura> f; public void add(Figura p) { f.add(p); } } 9 (C) package P1; import P2.*; abstract public class Figura { double x,y; final double PI=3.14159; Desenho d; abstract protected double dist(double x1,double y1); } package P1; public class Circulo extends Figura { double r; public Circulo() { d.add(this); } public double raio() { return r; } public double centroX() { return x; } public double centroY() { return y; } public double dist(double x1,double y1) { return Math.sqrt((x1-x)*(x1-x)+(y1-y)*(y1-y)); } } package P2; import java.util.List; import P1.Figura; public class Desenho { List<Figura> f; public void add(Figura p) { f.add(p); } } 10 (D) package P1; import P2.*; public class Circ implements ICirculo { double cx; double cy; double r; public double raio() { return r; } public double centroX() { return cx; } } package P2; public interface ICirculo { double PI; double raio(); double centroX(); double centroY(); } (E) package P1; import P2.*; public class Circ extends ICirculo { double cx; double cy; double r; public double raio() { return r; } public double centroX() { return cx; } public double centroY() { return cy; } } package P2; public interface ICirculo { double PI=3.14159; double raio(); double centroX(); double centroY(); } 11