设计模式-组合模式

目录

一:定义

二:案例

---

一:定义

适合树状带有包含信息的数据

例如:大学包含院系,院系包含学科

二:案例

// University就是Composite,可以管理College
@Data
public class University extends OrganizationComponent {

    List<OrganizationComponent> organizationComponentList = new ArrayList<>();

    // 构造器
    public University(String name, String desc) {
        super(name, desc);
    }

    // 重写add方法
    @Override
    public void add(OrganizationComponent organizationComponent) {
        organizationComponentList.add(organizationComponent);
    }

    // 重写remove方法
    @Override
    public void remove(OrganizationComponent organizationComponent) {
        organizationComponentList.remove(organizationComponent);
    }

    // print方法,就是输出University 包含的学院
    @Override
    public void print() {
        System.out.println("==========" + super.getName() + "==========");
        // 遍历organizationComponentList
        for (OrganizationComponent organizationComponent : organizationComponentList) {
            organizationComponent.print();
        }
    }
}

public class College extends OrganizationComponent{

    // List中存放的是Department
    List<OrganizationComponent> organizationComponentList = new ArrayList<>();

    // 构造器
    public College(String name, String desc) {
        super(name, desc);
    }

    // 重写add方法
    @Override
    public void add(OrganizationComponent organizationComponent) {
        // 将来实际业务中, College的add和University的add 不一定完全一样
        organizationComponentList.add(organizationComponent);
    }

    // 重写remove方法
    @Override
    public void remove(OrganizationComponent organizationComponent) {
        organizationComponentList.remove(organizationComponent);
    }

    // print方法,就是输出University 包含的学院
    @Override
    public void print() {
        System.out.println("==========" + super.getName() + "==========");
        // 遍历organizationComponentList
        for (OrganizationComponent organizationComponent : organizationComponentList) {
            organizationComponent.print();
        }
    }
}

 

 

public class Department extends OrganizationComponent {

    public Department(String name, String desc) {
        super(name, desc);
    }

    // add和remove方法就不用写了,因为他是叶子节点


    @Override
    public void print() {
        System.out.println(getName());
    }
}

@Data
@AllArgsConstructor
@NoArgsConstructor
public abstract class OrganizationComponent {
    private String name;// 名字
    private String des;// 描述

    protected void add(OrganizationComponent organizationComponent) {
        // 默认实现
        throw new UnsupportedOperationException();
    }

    protected void remove(OrganizationComponent organizationComponent) {
        // 默认实现
        throw new UnsupportedOperationException();
    }

    // 打印方法
    public abstract void print();
    
}

 

public class Client {
    public static void main(String[] args) {
        // 从大到小创建对象
        OrganizationComponent university = new University("清华大学", "顶级大学");

        // 创建学院
        OrganizationComponent computerCollege = new College("计算机学院", "计算机学院");
        OrganizationComponent infoEngineerCollege = new College("信息工程学院", "信息工程学院");

        // 创建各个学院下面的系
        computerCollege.add(new Department("软件工程", "软件工程"));
        computerCollege.add(new Department("网络工程", "网络工程"));


        infoEngineerCollege.add(new Department("通信工程", "通信工程"));
        infoEngineerCollege.add(new Department("信息工程", "信息工程"));

        // 将两个学院加入到学校
        university.add(computerCollege);
        university.add(infoEngineerCollege);

        university.print();

    }
}