SE450: Basics: Composition (Exclusive Reference) [39/63]

file:Person.java [source] [doc-public] [doc-private]

01 02 03 04 05 06 07 08 09 package basics.composition; import java.util.Random; final class Person { static private Random random = new Random(); final private String name; public Person() { name = Integer.toString(random.nextInt()); } //public Person(String name) { name = name.clone(); } public String toString() { return "Person(" + name + ")"; }; }

Exclusive reference to objects of another class:

   +--------+    name  +--------+
   | Person |<@>------>| String |
   +--------+          +--------+

In UML, this is called composition.

Consequences of composition:

• When the person dies, the name dies too
• Name can only be accessed through the person

(Yuck! We've mixed static and non-static members!)