Book Image

Oracle Certified Associate, Java SE 7 Programmer Study Guide

By : Richard M. Reese
Book Image

Oracle Certified Associate, Java SE 7 Programmer Study Guide

By: Richard M. Reese

Overview of this book

<p>Java SE 7 Associate Programmer certification adds to your qualification as a Java developer. Knowledge of Java is important, but knowing how to write an efficient and productive code adds to your skills and gives you an edge when you are planning to give the certification exam. Coverage of the objectives goes beyond a simple review of certification objectives.</p> <p>"Oracle Certified Associate, Java SE 7 Programmer Study Guide" addresses certification exam objectives and provides discussion and examples to show the best ways of applying Java language features in real world programming. You will gain in-depth understanding of Java by examining how objects are allocated in the heap and how methods are managed in the program stack.<br /><br />"Oracle Certified Associate, Java SE 7 Programmer Study Guide" covers all of the Java SE 7 Associate Programmer certification objectives. It starts with a high level overview of an application’s structure to provide a framework for subsequent chapters. Chapters are organized around common themes with emphasis on memory usage. You will get an in-depth and complete understanding of the run-time Java environment using the illustrations that show the impact of class and method usage on the program stack and heap. <br /><br />Augmenting the coverage of certification objectives are examples of how you can use the classes, methods, and techniques in a productive and sound manner. In addition, sample exam questions are given in each chapter.</p>
Table of Contents (16 chapters)
Oracle Certified Associate, Java SE 7 Programmer Study Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Inheritance


Inheritance is concerned with the relationship between two classes—the base class and the derived class. In this section we will cover the following:

  • Implementing a subclass

  • Using the protected keyword

  • Overriding methods

  • Using the @Override annotation

  • Using the final keyword with classes

  • Creating abstract methods and classes

The use of constructors and inheritance is covered in the The super keyword and constructors section.

When inheritance occurs, the derived class inherits all of the methods and attributes of the base class. However, it can only access the public and protected members of the class. It cannot access the private members of the class.

When a method is added to a derived class that has the same signature and accessibility of a base class method, the method is said to override the base class method. This allows the derived class to redefine the meaning of that method. The examples in this chapter will use a Employee base class and a SalaryEmployee class that is derived...