Relationship in Java

There are three type of relationships in java

• Generalized and Specialization(is a -relationship)
• A class is similar to other class
• A class is different type of another class. 

         

• Aggregation(has a -relationship)
• A class has a Object of other class as member variable
• Another class is part of class

• Every customer have Address
• Relationship between Address class and Customer class is Has-a relationship

• Association (uses a-relationship)


• loosely coupled relationship
•  A class interact with other class

• Every bill payment have some header to it so Purchase class uses PrintHeader class to print the header
• Relationship between purchase class and PrintHeader class is Uses_a relationship

Implementation of Relationship 

• Inheritance
• Aggregation
• Association