package com.mufeng.theninthchapter;

class A {
	interface B {
		void f();
	}

	public class BImp implements B {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}
	}

	private class BImp2 implements B {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}
	}

	public interface C {
		void f();
	}

	class CImp implements C {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}
	}

	private class CImp2 implements C {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}

	}

	private interface D {
		void f();
	}

	private class DImp implements D {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}
	}

	public class DImp2 implements D {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}
	}

	public D getD() {
		return new DImp2();
	}

	private D dRef;

	public void receiveD(D d) {
		dRef = d;
		dRef.f();
	}
}

interface E {
	interface G {
		void f();
	}

	public interface H {
		void f();
	}

	void g();

	// Cannot be private within an interface:
	// private interface I{
	// void f();
	// }
}

public class NestingInterfaces {

	public class BImp implements A.B {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}
	}

	class CImp implements A.C {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}
	}

	// Cannot implement a private interface except
	// within that interface's defining class
	// class DImp implements A.D {
	// @Override
	// public void f() {
	// // TODO Auto-generated method stub
	//
	// }
	// }

	class EImp implements E {

		@Override
		public void g() {
			// TODO Auto-generated method stub

		}
	}

	class EGImp implements E.G {

		@Override
		public void f() {
			// TODO Auto-generated method stub

		}

	}

	class EImp2 implements E {

		@Override
		public void g() {
			// TODO Auto-generated method stub

		}

		class EG implements E.G {

			@Override
			public void f() {
				// TODO Auto-generated method stub

			}

		}
	}

	public static void main(String[] args) {
		A a = new A();
		// Can't access A.D
		// !A.D ad=a.getD();

		// Doesn't return anything but A.D
		//!A.DImp2 di2 = a.getD();
		
		//Cannot access a member of the interface
		//!a.getD().f();
		
		//Only another A can do anything with getD():
		A a2=new A();
		a2.receiveD(a.getD());
	}

}

源码解析