class A {
public String show(D obj){
return ("A and D");
}
public String show(A obj){
return ("A and A");
}
}
class B extends A{
public String show(B obj){
return ("B and B");
}
public String show(A obj){
return ("B and A");
}
}
class C extends B{}
class D extends B{}
class DynamicTest
{
public static void main(String[] args){
A a1 = new A();
A a2 = new B();
B b = new B();
C c = new C();
D d = new D();
System.out.println(a1.show(b));
System.out.println(a1.show(c));
System.out.println(a1.show(d));
System.out.println(a2.show(b));
System.out.println(a2.show(c));
System.out.println(a2.show(d));
System.out.println(b.show(b));
System.out.println(b.show(c));
System.out.println(b.show(d));
实际上这里涉及方法调用的优先级问题,优先级由高到低依次为:
this.show()--->super.show()-->this.show((super)0)-->super.show((super)0)
System.out.println(a1.show(b)); A and A
System.out.println(a1.show(c)); A and A
System.out.println(a1.show(d)); A and D
System.out.println(a2.show(b)); B and A
System.out.println(a2.show(c)); B and A
System.out.println(a2.show(d)); A and D
System.out.println(b.show(b)); B and B
System.out.println(b.show(c)); B and B
System.out.println(b.show(d)); A and D
