一、前言：
组合模式的注意事项与细节：
- 简化了客户端的操作，客户端只需面对对象，而不需考虑部分与整体问题。
- 具有较强的扩展性，需要调整时，只需更改组合内部结构的层次关系（树结构），客户端无需更改。
- 很高的抽象性，如果节点与叶子差异性过大时，不推荐使用组合模式。
二、UML图：
三、组合模式：
3.1、代码实例：
Step 1) 创建 OrganizationComponent 抽象类：
public abstract class OrganizationComponent {
private String mane;
private String des;
protected void add(OrganizationComponent organizationComponent){
throw new UnsupportedOperationException();
}
protected void remove(OrganizationComponent organizationComponent){
throw new UnsupportedOperationException();
}
public OrganizationComponent() {
}
public OrganizationComponent(String mane, String des) {
this.mane = mane;
this.des = des;
}
public String getMane() {
return mane;
}
public void setMane(String mane) {
this.mane = mane;
}
public String getDes() {
return des;
}
public void setDes(String des) {
this.des = des;
}
protected abstract void print();
}
Step 2) 创建 University 实现类：
public class University extends OrganizationComponent{
List<OrganizationComponent> organizationComponents = new ArrayList<>();
public University(String mane, String des) {
super(mane, des);
}
@Override
protected void add(OrganizationComponent organizationComponent) {
organizationComponents.add(organizationComponent);
}
@Override
protected void remove(OrganizationComponent organizationComponent) {
organizationComponents.remove(organizationComponent);
}
@Override
public String getDes() {
return super.getDes();
}
@Override
public String getMane() {
return super.getMane();
}
@Override
protected void print() {
System.out.println("-------------"+ getMane()+"------------------------");
for (OrganizationComponent o : organizationComponents){
o.print();
}
}
}
Step 3) 创建 College 实现类：
public class College extends OrganizationComponent{
List<OrganizationComponent> organizationComponents = new ArrayList<>();
public College(String mane, String des) {
super(mane, des);
}
@Override
protected void add(OrganizationComponent organizationComponent) {
organizationComponents.add(organizationComponent);
}
@Override
protected void remove(OrganizationComponent organizationComponent) {
organizationComponents.remove(organizationComponent);
}
@Override
public String getDes() {
return super.getDes();
}
@Override
public String getMane() {
return super.getMane();
}
@Override
protected void print() {
System.out.println("-------------"+ getMane()+"------------------------");
for (OrganizationComponent o : organizationComponents){
o.print();
}
}
}
Step 4) 创建 Department 实现类：
public class Department extends OrganizationComponent{
public Department() {
}
public Department(String mane, String des) {
super(mane, des);
}
@Override
protected void print() {
System.out.println(getMane());
}
}
Step 5) 创建 main 方法：
public class Client {
public static void main(String[] args) {
OrganizationComponent university = new University("清华大学", "中国顶级大学");
OrganizationComponent compuyerCollege = new University("计算机学院", "计算机学院");
OrganizationComponent infoEnginerCollege = new University("信息工程学院", "信息工程学院 ");
compuyerCollege.add(new Department("软件工程", "软件工程不错"));
compuyerCollege.add(new Department("网络工程", "网络工程不错"));
compuyerCollege.add(new Department("计算机科学与技术", "计算机科学与技术是老牌专业"));
infoEnginerCollege.add(new Department("通信工程", "通信工程不好学"));
infoEnginerCollege.add(new Department("信息工程", "信息工程好学"));
university.add(compuyerCollege);
university.add(infoEnginerCollege);
// university.print();
// compuyerCollege.print();
infoEnginerCollege.print();
}
}
• 由 ChiKong_Tam 写于 2020 年 10 月 18 日