2019独角兽企业重金招聘Python工程师标准>>>
1、接口方法用于回调 (这里定义接口是为了使用其接口方法):
public interface ICallback { public void func();
} public class Caller { ICallback callback; public void doCallback() { callback.func(); } public void setCallback(ICallback callback) { this.callback = callback; } } public class MainClass { public MainClass() { } public static void main(String[] args) { Caller caller = new Caller(); caller.setCallback(new ICallback () { public void func() { System.out.println("dosth"); } }); caller.doCallback(); }
}
2、向上转型
interface People{ void peopleList();
}
class Student implements People{ public void peopleList(){ System.out.println("I’m a student."); }
}
class Teacher implements People{ public void peopleList(){ System.out.println("I’m a teacher."); }
}
public class Example{ public static void main(String args[]){ People a; //声明接口变量 a=new Student(); //实例化,接口变量中存放对象的引用 a.peopleList(); //接口回调 a=new Teacher(); //实例化,接口变量中存放对象的引用 a.peopleList(); //接口回调 }
}
运行结果:
I’m a student.
I’m a teacher.
3、常量接口(这里不在讲)