Design pattern: interface isolation principle

LV Jingying 2021-01-23 16:48:02
design pattern interface isolation principle


The official definition of

Interface isolation principle (Interface Segregation Principe), Also known as ISP principle , The official definition is :

1、Clients should not be forced to depend upon interfaces that they don't use.

The client should not rely on interfaces it does not need

2、The dependency of one class to another one should depend on the smallest possible interface

Dependencies between classes should be based on minimal interfaces

Basic introduction

In layman's terms , Don't define too many methods in an interface , The interface should be the most detailed

Case presentation - Market situation

​ Suppose there is a case scenario , Now there's an interface knife, Given that he has three abilities , You can cut apples , Cut tomato , Cut potatoes , Two chefs , Chef Li has these abilities respectively , There is a kind of fruit shop , Suppose you need master Zhang to cut apples and tomatoes , Another kind of vegetable shop needs Master Li to cut tomatoes and potatoes

// Defining interfaces knife
interface knife{
// The ability to cut apples
void cutApple();
// The ability to cut tomatoes
void cutTomato();
// The ability to cut potatoes
void cutPotato();
}
// Chefs
class CookZhang implements Knife{
@Override
public void cutApple(){
System.out.println(" Chef Zhang is cutting fruit ");
}
@Override
public void cutTomato(){
System.out.println(" Chef Zhang is cutting tomatoes ");
}
@Override
public void cutPotato(){
System.out.println(" Chef Zhang is cutting potatoes ");
}
}
// Chef li
class CookLi implements Knife{
@Override
public void cutApple(){
System.out.println(" Chef Li is cutting fruit ");
}
@Override
public void cutTomato(){
System.out.println(" Chef Li is cutting tomatoes ");
}
@Override
public void cutPotato(){
System.out.println(" Chef Li is cutting potatoes ");
}
}
// Fruit shops
class FruitShop{
// Define methods
public void cutApple(Knife knife){
knife.cutApple();
}
public void cutTomato(Knife knife){
knife.cutTomato();
}
}
// Vegetable shops
class VegetableShop{
// Define methods
public void cutPotato(Knife knife){
knife.cutPotato();
}
public void cutTomato(Knife knife){
knife.cutTomato();
}
}
public class SegregationDemo{
public static void main(Stringp[] agrs){
// Fruit shops
new FruitShop.cutApple(new CookZhang());
new FruitShop.cutTomato(new CookZhang());
// Vegetable shops
new VegetableShop.cutTomato(new CookLi());
new VegetableShop.cutPotato(new CookLi());
}
}

case analysis

The above writing violates the principle of interface isolation , Master Zhang doesn't need to cut potatoes , Chef Li doesn't need to cut apples either

Violation of the principle that dependencies between classes should be based on minimal interfaces

Solution

// Will unveil kinfe Split into three separate interfaces
interface AppleKnife{
// The ability to cut apples
void cutApple();
}
interface TomatoKnife{
// The ability to cut tomatoes
void cutTomato();
}
interface PotatoKnife{
// The ability to cut potatoes
void cutPotato();
}
// Chefs
class CookZhang implements AppleKnife,TomatoKnife{
@Override
public void cutApple(){
System.out.println(" Chef Zhang is cutting fruit ");
}
@Override
public void cutTomato(){
System.out.println(" Chef Zhang is cutting tomatoes ");
}
}
// Chef li
class CookLi implements TomatoKnife,PotatoKnife{
@Override
public void cutTomato(){
System.out.println(" Chef Li is cutting tomatoes ");
}
@Override
public void cutPotato(){
System.out.println(" Chef Li is cutting potatoes ");
}
}
// Fruit shops
class FruitShop{
// Define methods
public void cutApple(AppleKnife knife){
knife.cutApple();
}
public void cutTomato(TomatoKnife knife){
knife.cutTomato();
}
}
// Vegetable shops
class VegetableShop{
// Define methods
public void cutPotato(PotatoKnife knife){
knife.cutPotato();
}
public void cutTomato(TomatoKnife knife){
knife.cutTomato();
}
}
public class SegregationDemo{
public static void main(Stringp[] agrs){
// Fruit shops
new FruitShop.cutApple(new CookZhang());
new FruitShop.cutTomato(new CookZhang());
// Vegetable shops
new VegetableShop.cutTomato(new CookLi());
new VegetableShop.cutPotato(new CookLi());
}
}

Case summary

The principle of interface isolation is that when a class relies on an interface ( Use ) When it's another class , Make sure that the interface you depend on is minimal , It's not used in the interface , Just isolate it , And isolation is , Split the original interface , Split into minimum granularity , To avoid coupling .

Compared with the principle of single responsibility

Principle of single responsibility : A reasonable breakdown of responsibilities , A class is responsible for only one responsibility

Interface isolation principle : Dependencies between classes should be based on minimal interfaces

The same thing

Both require the structure to be split , Both require smaller granularity , Both require less coupling

Difference

Different perspectives

Principle of single responsibility : Class and interface have a single responsibility , Focus on responsibility

Interface isolation principle : We are required to use as many specialized interfaces as possible , Focus on the interface design

When we use the principle of interface isolation to split interfaces , We should follow the principle of single responsibility

版权声明
本文为[LV Jingying]所创,转载请带上原文链接,感谢
https://javamana.com/2021/01/20210123164741449d.html

  1. 【计算机网络 12(1),尚学堂马士兵Java视频教程
  2. 【程序猿历程,史上最全的Java面试题集锦在这里
  3. 【程序猿历程(1),Javaweb视频教程百度云
  4. Notes on MySQL 45 lectures (1-7)
  5. [computer network 12 (1), Shang Xuetang Ma soldier java video tutorial
  6. The most complete collection of Java interview questions in history is here
  7. [process of program ape (1), JavaWeb video tutorial, baidu cloud
  8. Notes on MySQL 45 lectures (1-7)
  9. 精进 Spring Boot 03:Spring Boot 的配置文件和配置管理,以及用三种方式读取配置文件
  10. Refined spring boot 03: spring boot configuration files and configuration management, and reading configuration files in three ways
  11. 精进 Spring Boot 03:Spring Boot 的配置文件和配置管理,以及用三种方式读取配置文件
  12. Refined spring boot 03: spring boot configuration files and configuration management, and reading configuration files in three ways
  13. 【递归,Java传智播客笔记
  14. [recursion, Java intelligence podcast notes
  15. [adhere to painting for 386 days] the beginning of spring of 24 solar terms
  16. K8S系列第八篇(Service、EndPoints以及高可用kubeadm部署)
  17. K8s Series Part 8 (service, endpoints and high availability kubeadm deployment)
  18. 【重识 HTML (3),350道Java面试真题分享
  19. 【重识 HTML (2),Java并发编程必会的多线程你竟然还不会
  20. 【重识 HTML (1),二本Java小菜鸟4面字节跳动被秒成渣渣
  21. [re recognize HTML (3) and share 350 real Java interview questions
  22. [re recognize HTML (2). Multithreading is a must for Java Concurrent Programming. How dare you not
  23. [re recognize HTML (1), two Java rookies' 4-sided bytes beat and become slag in seconds
  24. 造轮子系列之RPC 1:如何从零开始开发RPC框架
  25. RPC 1: how to develop RPC framework from scratch
  26. 造轮子系列之RPC 1:如何从零开始开发RPC框架
  27. RPC 1: how to develop RPC framework from scratch
  28. 一次性捋清楚吧,对乱糟糟的,Spring事务扩展机制
  29. 一文彻底弄懂如何选择抽象类还是接口,连续四年百度Java岗必问面试题
  30. Redis常用命令
  31. 一双拖鞋引发的血案,狂神说Java系列笔记
  32. 一、mysql基础安装
  33. 一位程序员的独白:尽管我一生坎坷,Java框架面试基础
  34. Clear it all at once. For the messy, spring transaction extension mechanism
  35. A thorough understanding of how to choose abstract classes or interfaces, baidu Java post must ask interview questions for four consecutive years
  36. Redis common commands
  37. A pair of slippers triggered the murder, crazy God said java series notes
  38. 1、 MySQL basic installation
  39. Monologue of a programmer: despite my ups and downs in my life, Java framework is the foundation of interview
  40. 【大厂面试】三面三问Spring循环依赖,请一定要把这篇看完(建议收藏)
  41. 一线互联网企业中,springboot入门项目
  42. 一篇文带你入门SSM框架Spring开发,帮你快速拿Offer
  43. 【面试资料】Java全集、微服务、大数据、数据结构与算法、机器学习知识最全总结,283页pdf
  44. 【leetcode刷题】24.数组中重复的数字——Java版
  45. 【leetcode刷题】23.对称二叉树——Java版
  46. 【leetcode刷题】22.二叉树的中序遍历——Java版
  47. 【leetcode刷题】21.三数之和——Java版
  48. 【leetcode刷题】20.最长回文子串——Java版
  49. 【leetcode刷题】19.回文链表——Java版
  50. 【leetcode刷题】18.反转链表——Java版
  51. 【leetcode刷题】17.相交链表——Java&python版
  52. 【leetcode刷题】16.环形链表——Java版
  53. 【leetcode刷题】15.汉明距离——Java版
  54. 【leetcode刷题】14.找到所有数组中消失的数字——Java版
  55. 【leetcode刷题】13.比特位计数——Java版
  56. oracle控制用户权限命令
  57. 三年Java开发,继阿里,鲁班二期Java架构师
  58. Oracle必须要启动的服务
  59. 万字长文!深入剖析HashMap,Java基础笔试题大全带答案
  60. 一问Kafka就心慌?我却凭着这份,图灵学院vip课程百度云