Book Image

Java Fundamentals

By : Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare
Book Image

Java Fundamentals

By: Gazihan Alankus, Rogério Theodoro de Brito, Basheer Ahamed Fazal, Vinicius Isola, Miles Obare

Overview of this book

Since its inception, Java has stormed the programming world. Its features and functionalities provide developers with the tools needed to write robust cross-platform applications. Java Fundamentals introduces you to these tools and functionalities that will enable you to create Java programs. The book begins with an introduction to the language, its philosophy, and evolution over time, until the latest release. You'll learn how the javac/java tools work and what Java packages are - the way a Java program is usually organized. Once you are comfortable with this, you'll be introduced to advanced concepts of the language, such as control flow keywords. You'll explore object-oriented programming and the part it plays in making Java what it is. In the concluding chapters, you'll get to grips with classes, typecasting, and interfaces, and understand the use of data structures, arrays, strings, handling exceptions, and creating generics. By the end of this book, you will have learned to write programs, automate tasks, and follow advanced courses on algorithms and data structures or explore more advanced Java courses.
Table of Contents (12 chapters)
Java Fundamentals
Preface

Exception Sources


When an exceptional case occurs in code, an exception object is thrown by the source of the problem, which is in turn caught by one of the callers in the call stack. The exception object is an instance of one of the exception classes. There are many such classes, which represent various types of problems. In this topic, we will take a look at different types of exceptions, get to know some of the exception classes from Java libraries, learn how to create our own exceptions, and see how to throw them.

In the previous topic, we first played with IOException. Then, in the activity, we played with NumberFormatException. There was a difference between these two exceptions. The IDE would force us to handle IOException and would not compile our code otherwise. However, it did not care whether we caught NumberFormatException or not, it would still compile and run our code. The difference was in the class hierarchy. While both of them are descendants of the Exception class, NumberFormatException...