例5-14和例5-15和例5-16
public class Example5_14 {
public static void main(String args[]) {
Pillar pillar;
Geometry tuxing;
tuxing=new Lader(12,22,100);
System.out.println("梯形的面积"+tuxing.getArea());
pillar=new Pillar(tuxing,58);
System.out.println("梯形底的柱体的体积"+pillar.getVolume());
tuxing=new Circle(10);
System.out.println("半径是10的圆的面积"+tuxing.getArea());
pillar.changeBottom(tuxing);
System.out.println("圆形底的柱体的体积"+pillar.getVolume());
}
}
public interface Geometry {
public abstract double getArea();
}
public class Pillar {
Geometry bottom;
double height;
Pillar(Geometry bottom,double height){
this.bottom=bottom;
this.height=height;
}
void changeBottom(Geometry bottom){
this.bottom=bottom;
}
public double getVolume(){
return bottom.getArea()*height;
}
}
public class Lader implements Geometry {
double a,b,h;
Lader(double a,double b,double h){
this.a=a;this.b=b;this.h=h;
}
public double getArea(){
return((1/2.0)*(a+b)*h);
}
}
public class Circle implements Geometry{
double r;
Circle(double r){
this.r=r;
}
public double getArea(){
return(3.14*r*r);
}
}
class NorthEast{
String land="黑土地";
}
class China{
int x=10,y=10;
LiaoNing dalian;
China(){
dalian=new LiaoNing();
}
void f(){
System.out.println("我是中国");
dalian.speak();
}
class LiaoNing extends NorthEast{
int z; void speak(){
System.out.println("我是大连,z="+z+":"+land);
}
void g(){
z=x+y;
f(); }
}
}
public class Example5_15 {
public static void main(String[] args) {
China china=new China();
china.f();
china.dalian.g();
}
}
abstract class Student{
abstract void speak();
}
class Teacher{
void look(Student stu){
stu.speak();
}
}
public class Example5_16 {
public static void main(String[] args) {
Teacher zhang=new Teacher();
zhang.look(new Student(){
void speak(){
System.out.println("这是匿名类中的方法");
}
}
);
}
}
