JAVA 设计者模式8(组合模式composite）

当需要处理一个有层次结构的数据时便于使用组合模式。比如需要输出公司组织机构的包含关系数据。
组合模式创建了对象组的树形结构，同时表示数据的层次关系。
依据树形结构来组合对象来表示整体部分的层次关系。这种数据类型的模式属于结构型模式。组合模式是用户对单个对象和组合对象的访问具有一致性。

代码示例：

public abstract class OrganizationComposite {
    private String name;
    private String des;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDes() {
        return des;
    }

    public void setDes(String des) {
        this.des = des;
    }

    public OrganizationComposite(String name, String des) {
        this.name = name;
        this.des = des;
    }

    protected void add(OrganizationComposite organizationComposite) {
        throw new UnsupportedOperationException();
    }

    protected void remove(OrganizationComposite organizationComposite) {
        throw new UnsupportedOperationException();
    }

    protected abstract void print();
}

public class Unversity extends OrganizationComposite {

    List organizationComposites = new ArrayList<>();

    public Unversity(String name, String des) {
        super(name, des);
    }

    @Override
    protected void add(OrganizationComposite organizationComposite) {
        organizationComposites.add(organizationComposite);
    }

    @Override
    protected void remove(OrganizationComposite organizationComposite) {
        organizationComposites.remove(organizationComposite);
    }

    @Override
    public String getDes() {
        return super.getDes();
    }

    @Override
    public String getName() {
        return super.getName();
    }

    @Override
    protected void print() {
        System.out.println("===========" + getName() + "==========");
        for (OrganizationComposite organizationComposite : organizationComposites) {
            organizationComposite.print();
        }
    }
}

public class College extends OrganizationComposite {

    List organizationComposites = new ArrayList<>();

    public College(String name, String des) {
        super(name, des);
    }

    @Override
    protected void add(OrganizationComposite organizationComposite) {
        organizationComposites.add(organizationComposite);
    }

    @Override
    protected void remove(OrganizationComposite organizationComposite) {
        organizationComposites.remove(organizationComposite);
    }

    @Override
    public String getName() {
        return super.getName();
    }

    @Override
    public String getDes() {
        return super.getDes();
    }

    @Override
    protected void print() {
        System.out.println("===========" + getName() + "==========");
        for (OrganizationComposite organizationComposite : organizationComposites) {
            organizationComposite.print();
        }
    }
}

public class Department extends OrganizationComposite {

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

    @Override
    public String getDes() {
        return super.getDes();
    }

    @Override
    public String getName() {
        return super.getName();
    }

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

public class Client {
    public static void main(String[] args) {

        OrganizationComposite  unversityComposite=new Unversity("南昌大学","南昌最有名的大学");

        OrganizationComposite collegeComposite=new College("南昌信息院","挺不错的");
        OrganizationComposite collegeComposite2=new College("南昌计算机院","挺有趣的");

        unversityComposite.add(collegeComposite);
        unversityComposite.add(collegeComposite2);

        OrganizationComposite department=new Department("java 软件开发","非你莫属");
        OrganizationComposite department2=new Department("网络编程","你来就对了");

        collegeComposite.add(department);
        collegeComposite2.add(department2);

        unversityComposite.print();
    }
}

简化客户端操作，客户端只需要面对一致的对象，而不需要考虑整体部分或叶子部分。具有较强的扩展性。方便创建出复杂的层次结构。