Java设计模式 | 七大原则之接口隔离原则

接口隔离原则（Interface Segregation Principle）

基本介绍

客户端不应该依赖他不需要的接口，即一个类对另一个类的依赖应建立在最小的接口上
如下图

A类通过接口Interface1依赖B类，C类通过接口Interface1依赖D类。如果Interface1对于A类和C类来说不是最小接口，那么B类和D类必须去实现他们不需要的方法
遵循接口隔离原则应这样处理：将接口Interface1拆分为独立的几个接口，A类和C类分别与他们需要的接口建立依赖关系。也就是采用接口隔离原则

应用实例

java 复制代码

/**
 * Created with IntelliJ IDEA.
 * User: Mingda
 * Time: 2024/2/23 17:05
 * File: Segregation1
 * Description: 接口隔离原则
 */
public class Segregation1 {

    public static void main(String[] args) {
        A a = new A();

        // A类通过接口去依赖B类
        a.method1(new B());
        a.method2(new B());
        a.method3(new B());

        C c = new C();
        // C类通过接口去依赖D类
        c.method1(new D());
        c.method4(new D());
        c.method5(new D());
    }
}

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

// B类
class B implements Interface1 {
    public void operation1() {
        System.out.println("B operation1");
    }

    public void operation2() {
        System.out.println("B operation2");
    }

    public void operation3() {
        System.out.println("B operation3");
    }

    public void operation4() {
        System.out.println("B operation4");
    }

    public void operation5() {
        System.out.println("B operation5");
    }
}

// D类
class D implements Interface1 {
    public void operation1() {
        System.out.println("D operation1");
    }

    public void operation2() {
        System.out.println("D operation2");
    }

    public void operation3() {
        System.out.println("D operation3");
    }

    public void operation4() {
        System.out.println("D operation4");
    }

    public void operation5() {
        System.out.println("D operation5");
    }
}

/**
 * A类通过接口Interface1依赖（使用）B类，但是只会使用operation1()、operation2()、operation3()方法
 */
class A {
    public void method1(Interface1 i) {
        i.operation1();
    }

    public void method2(Interface1 i) {
        i.operation2();
    }
    public void method3(Interface1 i) {
        i.operation3();
    }
}

/**
 * C类通过接口Interface1依赖（使用）D类，但是只会使用operation1()、operation4()、operation5()方法
 */
class C {

    public void method1(Interface1 i) {
        i.operation4();
    }

    public void method4(Interface1 i) {
        i.operation4();
    }

    public void method5(Interface1 i) {
        i.operation5();
    }
}

java 复制代码

/**
 * Created with IntelliJ IDEA.
 * User: Mingda
 * Time: 2024/2/23 17:05
 * File: Segregation1
 * Description: 接口隔离原则
 */
public class Segregation2 {

    public static void main(String[] args) {
        A a = new A();

        // A类通过接口去依赖B类
        a.method1(new B());
        a.method2(new B());
        a.method3(new B());

        C c = new C();

        // C类通过接口去依赖D类
        c.method1(new D());
        c.method4(new D());
        c.method5(new D());
    }
}

// 接口1
interface Interface1 {
    void operation1();
}

// 接口2
interface Interface2 {
    void operation2();
    void operation3();
}

// 接口3
interface Interface3 {
    void operation4();
    void operation5();
}

// B类
class B implements Interface1, Interface2 {
    public void operation1() {
        System.out.println("B operation1");
    }

    @Override
    public void operation2() {
        System.out.println("B operation2");
    }

    @Override
    public void operation3() {
        System.out.println("B operation3");
    }
}

// D类
class D implements Interface1, Interface3 {
    public void operation1() {
        System.out.println("D operation1");
    }

    @Override
    public void operation4() {
        System.out.println("D operation4");
    }

    @Override
    public void operation5() {
        System.out.println("D operation5");
    }
}

/**
 * A类通过接口Interface1、Interface2依赖（使用）B类，使用operation1()、operation2()、operation3()方法
 */
class A {
    public void method1(Interface1 i) {
        i.operation1();
    }

    public void method2(Interface2 i) {
        i.operation2();
    }
    public void method3(Interface2 i) {
        i.operation3();
    }
}

/**
 * C类通过接口Interface1、Interface3依赖（使用）D类，使用operation1()、operation4()、operation5()方法
 */
class C {

    public void method1(Interface1 i) {
        i.operation1();
    }

    public void method4(Interface3 i) {
        i.operation4();
    }

    public void method5(Interface3 i) {
        i.operation5();
    }
}

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