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

Exception types


Java has provided an extensive set of classes to support exception handling in Java. An exception is an instance of a class derived directly, or indirectly, from the Throwable class. Two predefined Java classes are derived from ThrowableError and Exception. From the Exception class is derived a RuntimeException class. As we will see shortly, programmer-defined exceptions are normally derived from the Exception class:

There are numerous pre-defined errors that are derived from the Error and RuntimeException classes. There is little that a programmer will do with the exceptions derived from the Error object. These exceptions represent problems with the JVM and normally can't be recovered. The Exception class is different. The two classes that derive from the Exception class support two types of exceptions:

  • Checked: These are exceptions that need to be dealt with in the code

  • Unchecked: These are exceptions that do not need to be dealt with in the code

Checked exceptions include...