Combination mode (Composite pattern)

Combination mode: A set of similar objects as a single object, based on a tree structure to combine objects, to represent parts and the whole hierarchy.

Give an example of managing a company's employees:

 Public classEmployee {PrivateString name; PrivateString Dept; Private Doublesalary; PrivateList<employee>Sub;  PublicEmployee (String n,string D,ints) {name=N; Dept=D; Salary=s; Sub=NewArraylist<employee>(); }     Public voidAdd (Employee e) {sub.add (e); }     Public voidRemove (Emplyee e) {sub.remove (e); }
Public list<employee> getsub () {
return sub;
}

 Public String toString () {        return "name:" + name + "Dept:" + Depr + "Salary:" + salary;   }}

Test code:

Employee CEO =NewEmployee ("A0", "CEO", 30000); Employee headmarketing=NewEmployee ("B0", "Head Marketing", 20000); Employee Clerk1=NewEmployee ("C0", "Marketing", 10000); Employee CLERK2=NewEmployee ("C1", "Marketing", 10000); Employee Headsales=NewEmployee ("B1", "Head Sales", 20000); Employee Sale1=NewEmployee ("C2", "Marketing", 10000); Employee Sale2=NewEmployee ("C3", "Marketing", 10000);    Ceo.add (headmarking); //CEO Management HeadmarkingCeo.add (Headsales);//CEO Management HeadsalesHeadmarking.add (CLERK1); //headmarking Management Two personsHeadmarking.add (CLERK2); Headsales.add (Sale1); //headsales Management Two personsHeadsales.add (sale2);//Print all EmployeesSystem.out.println (CEO); for(Employee e1:CEO.getSub ()) {System.out.println (E1);  for(Employee e2:e1.getSub ()) {System.out.println (E2); }}

The combination mode is suitable for dealing with tree structure problems, such as tree menu, folder file management.

Combination mode (Composite pattern)