组合模式（Composite Pattern）

public class Employee {
private String name;
private String dept;
private double salary;
private List<Employee> sub;

public Employee(String n,String d,int s) {
name = n;
dept = d;
salary = s;
sub = new ArrayList<Employee>();
}
public void add(Employee e) {
sub.add(e);
}
public void remove(Emplyee e) {
sub.remove(e);
}
public List<Employee> getSub() {
　　　　return sub;
　　}

public String toString() {
return "Name:" + name + "dept:" + depr + "salary:" + salary;
}
}

Employee CEO = new Employee("A0","CEO",30000);

Employee headMarketing = new Employee("B0","Head Marketing", 20000);
Employee clerk1 = new Employee("C0","Marketing",10000);
Employee clerk2 = new Employee("C1","Marketing",10000);

Employee headSales = new Employee("B1","Head Sales",20000);
Employee sale1 = new Employee("C2","Marketing",10000);
Employee sale2 = new Employee("C3","Marketing",10000);

CEO.add(headMarking);    //CEO管理headMarking
CEO.add(headSales);       // CEO管理headSales

headMarking.add(clerk1);   //headMarking管理两个人
headMarking.add(clerk2);

headSales.add(sale1);    //headSales管理两个人
headSales.add(sale2);

//打印所有员工
System.out.println(CEO);
for(Employee e1 : CEO.getSub()) {
System.out.println(e1);
for(Employee e2: e1.getSub()) {
System.out.println(e2);
}
}