JAVA 匿名内部类

public interface A {

    public void func();

}

public class B implements A {

    public B() {
        // TODO Auto-generated constructor stub
    }

    @Override
    public void func() {
        // TODO Auto-generated method stub
        System.out.println("func B");
    }

}

public class C implements A {

    A a;

    public C() {
        // TODO Auto-generated constructor stub
    }

    public C(A a) {
        // TODO Auto-generated constructor stub
        this.a = a;
    }

    @Override
    public void func() {
        // TODO Auto-generated method stub
        System.out.println("func C");
        a.func();
    }

}

两种实现方式

public class Test {

    public Test() {
        // TODO Auto-generated constructor stub
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        B b = new B();
        C c = new C(b);
        c.func();

        C c1 = new C(new A() {

            @Override
            public void func() {
                // TODO Auto-generated method stub
                System.out.println("new A()");
            }

        });
        c1.func();
    }

}

运行结果

func C
func B
func C
new A()