标签:构造 void 微信消息 理念 out main open 传递 直接
面向接口编程,依赖于抽象而不是依赖与具体类,写具体类时通过接口进行交互
1. 基本介绍
(1)高层模块不应该依赖低层模块,二者都应该依赖抽象
(2)抽象不应该依赖细节,细节应该依赖抽象
(3)依赖倒置的中心思想是面向接口编程
(4)依赖倒置原则的设计理念,相对于细节的多变性,抽象的东西要稳定的多,以抽象为基础搭建的框架比以细节为基础的框架稳定,java中,抽象代表接口或抽象类,细节代表具体的实现类
(5)使用接口的目的是制定好规范,不涉及具体的操作,把具体的细节交给实现类完成
2. 应用场景
完成Person 接收消息
/**
* 完成Person 接收信息
* 1、如果需要接收别的信息时,需要新增类,同时Person 需要添加新的方法
* 2、解决思路: 定义一个接收的接口,person 类去实现,
* 3、如果需要接收别的信息,新增类可直接实现接收接口,实现接收信息
*/
static class Email {
public String getInfo() {
return "接收邮件信息";
}
}
static class Person {
public void receive(Email email) {
System.out.println(email.getInfo());
}
}
public static void main(String[] args) {
Person person = new Person();
person.receive(new Email());
//改进
PersonInfo personInfo = new PersonInfo();
personInfo.receive(new WeChat());
}
/**
* 改进方案 接收邮件、微信消息
*/
interface IReceive {
public String getInfo();
}
static class WeChat implements IReceive {
@Override
public String getInfo() {
return "接收微信消息";
}
}
static class PersonInfo {
//person 修改为对接口的依赖
public void receive(IReceive receive) {
System.out.println(receive.getInfo());
}
}`
3. 依赖传递的三种方式
公共的接口
interface ITv {
public void play();
}
static class ChangHong implements ITv {
@Override
public void play() {
System.out.println("打开电视机-----");
}
}
(1)通过接口传递
interface IOpen {
public void open(ITv tv);
}
static class Open implements IOpen {
@Override
public void open(ITv tv) {
tv.play();
}
}
public static void main(String[] args) {
ChangHong changHong = new ChangHong();
Open open = new Open();
open.open(changHong);
}`
(2)通过构造函数传递
interface IOpenAndClose {
public void open();
}
static class OpenAndClose implements IOpenAndClose {
private ITv tv;
//构造函数
public OpenAndClose(ITv tv) {
this.tv = tv;
}
@Override
public void open() {
tv.play();
}
}
public static void main(String[] args) {
ChangHong changHong = new ChangHong();
OpenAndClose openAndClose = new OpenAndClose(changHong);
openAndClose.open();
}
(3)通过setter方法传递
interface IOpenClose {
public void open();
//set
public void setOpen(ITv tv);
}
static class OpenClose implements IOpenClose {
private ITv tv;
@Override
public void open() {
this.tv.play();
}
@Override
public void setOpen(ITv tv) {
this.tv = tv;
}
}
public static void main(String[] args) {
ChangHong changHong = new ChangHong();
OpenClose openClose = new OpenClose();
openClose.setOpen(changHong);
openClose.open();
}
标签:构造 void 微信消息 理念 out main open 传递 直接
原文地址:https://blog.51cto.com/14804892/2491906