Data Abstraction in Java

Abstract Data Type

• Definition and Purpose of ADTs

  • Abstract Data Types (ADTs) are high-level data structures that encapsulate data and operations on that data. They provide a way to abstract and model real-world concepts or entities in software.

  • ADTs focus on the behavior and functionality of data rather than its implementation details, allowing programmers to work with data structures at a higher level of abstraction.

• Benefits of Using ADTs

  • Modularity: ADTs promote modular design by encapsulating data and operations, making it easier to manage and maintain complex systems.

  • Code Reusability: ADTs can be reused across multiple projects or modules, saving development time and effort.

  • Security and Reliability: ADTs enforce data integrity and encapsulation, reducing the risk of errors and ensuring reliable and secure data manipulation.

  • Abstraction: ADTs provide a higher-level abstraction, allowing programmers to focus on the problem domain rather than low-level implementation details.

ADT in Java

• Defined as Java interfaces

  • Not all interfaces are ADTs

• Collection of public interfaces are often known as a Java API (Application Programming Interface)

• Implemented as Java class that implements the interface

• Used in Java client classes

• Complicated inheritance hierarchy of ADTs may occur

  • Interface inheritance

  • Implementation inheritance

Note

This is in the ideal scenario. In practice, Java ADTs are often implemented directly as concrete classes if there are only a few implementations of the ADT.

Relationship to Data structures

• ADTs are a high-level abstraction of data structures

• Data structures are a low-level implementation of ADTs

• In Java

  • ADTs are defined as interfaces

  • Data structures are defined as classes that implement the ADT interfaces