一句話總結(jié)

星狀結(jié)構(gòu)

內(nèi)容

由對(duì)象直接耦合變成對(duì)象和中介者進(jìn)行關(guān)聯(lián),中介者在于其他對(duì)象進(jìn)行關(guān)聯(lián),將網(wǎng)狀結(jié)構(gòu)變成星狀結(jié)構(gòu)。

場景

朋友圈,信息交易平臺(tái)

類圖

image.png

代碼示例

// 抽象同事類
public abstract class Colleague {
    protected Mediator mediator;

    public Colleague(Mediator mediator) {
        this.mediator = mediator;
    }
}
// 具體同事類
public class ConcreteColleagueA extends Colleague {
    public ConcreteColleagueA(Mediator mediator) {
        super(mediator);
        this.mediator.setColleageA(this);
    }

    // 自有方法：self-Method
    public void selfMethodA() {
        // 處理自己的邏輯
        System.out.println(String.format("%s:self-Method", this.getClass().getSimpleName()));
    }

    // 依賴方法：dep-Method
    public void depMethodA() {
        // 處理自己的邏輯
        System.out.println(String.format("%s:depMethod: delegate to Mediator", this.getClass().getSimpleName()));
        // 無法處理的業(yè)務(wù)邏輯委托給中介者處理
        this.mediator.transferA();
    }
}
// 具體同事類
public class ConcreteColleagueB extends Colleague {
    public ConcreteColleagueB(Mediator mediator) {
        super(mediator);
        this.mediator.setColleageB(this);
    }

    // 自有方法：self-Method
    public void selfMethodB() {
        // 處理自己的邏輯
        System.out.println(String.format("%s:self-Method", this.getClass().getSimpleName()));
    }

    // 依賴方法：dep-Method
    public void depMethodB() {
        // 處理自己的邏輯
        System.out.println(String.format("%s:depMethod: delegate to Mediator", this.getClass().getSimpleName()));
        // 無法處理的業(yè)務(wù)邏輯委托給中介者處理
        this.mediator.transferB();
    }
}
// 抽象中介者
public abstract class Mediator {
    protected ConcreteColleagueA colleagueA;
    protected ConcreteColleagueB colleagueB;

    public void setColleageA(ConcreteColleagueA colleague) {
        this.colleagueA = colleague;
    }

    public void setColleageB(ConcreteColleagueB colleague) {
        this.colleagueB = colleague;
    }

    // 中介者業(yè)務(wù)邏輯
    public abstract void transferA();

    public abstract void transferB();
}
// 具體中介者
public class ConcreteMediator extends Mediator {
    @Override
    public void transferA() {
        // 協(xié)調(diào)行為:A 轉(zhuǎn)發(fā)到 B
        this.colleagueB.selfMethodB();
    }

    @Override
    public void transferB() {
        // 協(xié)調(diào)行為:B 轉(zhuǎn)發(fā)到 A
        this.colleagueA.selfMethodA();
    }
}
public class Test {
    public static void main(String[] args) {
        Mediator mediator = new ConcreteMediator();
        ConcreteColleagueA colleagueA = new ConcreteColleagueA(mediator);
        ConcreteColleagueB colleagueB = new ConcreteColleagueB(mediator);
        colleagueA.depMethodA();
        System.out.println("-------------------------");
        colleagueB.depMethodB();
    }
}

運(yùn)行結(jié)果

image.png