1. 组合模式介绍
在解决组织结构这种具有层级关系的结构中,如果使用传统的继承,不能很好的实现管理的操作,比如学院,系的添加,删除,遍历等;
所有可以使用组合模式把它们都看成组织结构,没有继承关系,而是一个树形结构。
2. 实现
public abstract class OrgComponent { private String name; private String desc; public OrgComponent(String name, String desc) { this.name = name; this.desc = desc; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDesc() { return desc; } public void setDesc(String desc) { this.desc = desc; } //默认实现,子类不需要都实现 protected void add(OrgComponent orgComponent){ throw new UnsupportedOperationException(); } protected void remove(OrgComponent orgComponent){ throw new UnsupportedOperationException(); } //抽象方法,子类都要实现 protected abstract void print(); }
public class University extends OrgComponent { List<OrgComponent> list = new ArrayList<>(); public University(String name, String desc) { super(name, desc); } @Override public String getName() { return super.getName(); } @Override public String getDesc() { return super.getDesc(); } @Override protected void add(OrgComponent orgComponent) { list.add(orgComponent); } @Override protected void remove(OrgComponent orgComponent) { list.remove(orgComponent); } @Override protected void print() { System.out.println("----" + getName() + "----"); for (OrgComponent orgComponent : list){ orgComponent.print(); } } }
public class College extends OrgComponent { List<OrgComponent> list = new ArrayList<>(); public College(String name, String desc) { super(name, desc); } @Override public String getName() { return super.getName(); } @Override public String getDesc() { return super.getDesc(); } @Override protected void add(OrgComponent orgComponent) { list.add(orgComponent); } @Override protected void remove(OrgComponent orgComponent) { list.remove(orgComponent); } @Override protected void print() { System.out.println("----" + getName() + "----"); for (OrgComponent orgComponent : list){ orgComponent.print(); } } }
public class Department extends OrgComponent { public Department(String name, String desc) { super(name, desc); } @Override public String getName() { return super.getName(); } @Override public String getDesc() { return super.getDesc(); } @Override protected void print() { System.out.println(getName()); } }
public class Client { public static void main(String[] args) { University university = new University("清华大学", "北京"); College computerCollege = new College("计算机学院","计算机"); College infoCollege = new College("信息工程学院", "信息"); computerCollege.add(new Department("软件工程","软件")); computerCollege.add(new Department("网络工程","网络")); infoCollege.add(new Department("通信工程","通信")); infoCollege.add(new Department("信息工程","信息")); university.add(computerCollege); university.add(infoCollege); university.print(); } }
3. 组合模式在JDK集合的源码分析
(1)hashMap就使用了组合模式,内部类Node就相当于叶子节点
标签:String,组合,void,模式,name,orgComponent,public,desc From: https://www.cnblogs.com/homle/p/18148986