接口隔离原则 Interface Segregation Principle

Posted 2020-11-27 thinkaboutmore

接口隔离原则介绍：

客户端不应该依赖它不需要的接口，即一个类对另一个类的依赖应该建立在最小的接口上

---

示例：

 

 错误示例：

package com.kittenplus.principle.segregation;

public class seregation2 {

    public static void main(String[] args) {
}

interface Interface1{
    void operation1();
    void operation2();
    void operation3();
    void operation4();
    void operation5();
}

class B implements Interface1{
    public void operation1() {
        System.out.println("B 实现了 operation1");
    }
    public void operation2() {
        System.out.println("B 实现了 operation2");
    }
    public void operation3() {
        System.out.println("B 实现了 operation3");
    }
    public void operation4() {
        System.out.println("B 实现了 operation4");
}
    public void operation5() {
        System.out.println("B 实现了 operation5");
}


class D implements Interface1{
    public void operation1() {
        System.out.println("D 实现了 operation1");
    }
    public void operation2() {
        System.out.println("D 实现了 operation2");
    }
    public void operation3() {
        System.out.println("D 实现了 operation3");
    }
    public void operation4() {
        System.out.println("D 实现了 operation4");
    }
    public void operation5() {
        System.out.println("D 实现了 operation5");
    }
}

class A {    //A 类通过 Interface1 依赖(使用)B类,但是只会用到1 2 3 方法
    public void depend1(Interface1 i) {
        i.operation1();
}
    public void depend2(Interface1 i) {
        i.operation2();
}
    public void depend3(Interface1 i) {
        i.operation3();
    }
}
    
    class C{    //C类通过 Interface1 依赖(使用)D类,但是只会用到1 4 5 方法
        public void depend1(Interface1 i) {
            i.operation1();
    }
        public void depend4(Interface1 i) {
            i.operation4();
    }
        public void depend5(Interface1 i) {
            i.operation5();
            }        
        }    
    }
}
    

 

 

 

正确方法：

package com.kittenplus.principle.segregation;

public class seregation2 {

    public static void main(String[] args) {
        A a = new A();
        a.depend1(new B()); //A类通过接口去依赖B类
        a.depend2(new B());
        a.depend3(new B());
        
        C c = new C();
        c.depend1(new D()); //C类通过接口去依赖(使用)D类
        c.depend4(new D());
        c.depend5(new D());
        
    }
}

interface Interface1{
    void operation1();
}
interface Interface2{
    void operation2();
    void operation3();
}
interface Interface3{
    void operation4();
    void operation5();
}

class B implements Interface1,Interface2{
    public void operation1() {
        System.out.println("B 实现了 operation1");
    }
    public void operation2() {
        System.out.println("B 实现了 operation2");
    }
    public void operation3() {
        System.out.println("B 实现了 operation3");
    }
}

class D implements Interface1,Interface3{
    public void operation1() {
        System.out.println("D 实现了 operation1");
    }
    public void operation4() {
        System.out.println("D 实现了 operation4");
    }
    public void operation5() {
        System.out.println("D 实现了 operation5");
    }
}

class A {    //A 类通过 Interface1 依赖(使用)B类,但是只会用到1 2 3 方法
    public void depend1(Interface1 i) {
        i.operation1();
}
    public void depend2(Interface2 i) {
        i.operation2();
}
    public void depend3(Interface2 i) {
        i.operation3();
    }
}
    
    class C{    //C类通过 Interface1 依赖(使用)D类,但是只会用到1 2 3 方法
        public void depend1(Interface1 i) {
            i.operation1();
    }
        public void depend4(Interface3 i) {
            i.operation4();
    }
        public void depend5(Interface3 i) {
            i.operation5();
    }        
}