Book Image

Transitioning to Java

By : Ken Fogel
Book Image

Transitioning to Java

By: Ken Fogel

Overview of this book

This comprehensive guide will help non-Java developers already using different languages transition from their current language to all things Java. The chapters are designed in a way that re-enforces a developer’s existing knowledge of object-oriented methodologies as they apply to Java. This book has been divided into four sections, with each section touching upon different aspects that’ll enable your effective transition. The first section helps you get to grips with the Java development environment and the Maven build tool for modern Java applications. In the second section, you’ll learn about Java language fundamentals, along with exploring object-oriented programming (OOP) methodologies and functional programming and discovering how to implement software design patterns in Java. The third section shows you how to code in Java on different platforms and helps you get familiar with the challenges faced on these platforms. In the fourth section, you’ll find out how you can manage and package your Java code. By the end of this Java programming book, you’ll have learned the core concepts of Java that’ll help you successfully transition from a different language to Java.
Table of Contents (23 chapters)
1
Part 1:The Java Development Environment
5
Part 2:Language Fundamentals
15
Part 3:GUI and Web Coding in Java
19
Part 4:Packaging Java Code

Handling exceptions

In Java, when things go wrong, they can be classified as errors or exceptions. An error is a problem that cannot be recovered from. An exception is an error that can be detected in your code such that you can possibly recover from it. For example, a recursion that never ends will result in a StackOverflowError-type error. Converting the Bob string to an integer will result in a NumberFormatException exception.

Here is a diagram of the primary exception classes:

Figure 7.1 – The exception hierarchy

Figure 7.1 – The exception hierarchy

Exceptions are objects of classes named after the type of exception that has occurred. In the diagram, you can see that at the root of the hierarchy is the Throwable class. From Throwable, we have two subclasses: Error and Exception. The subclasses of Error are named after the errors that may occur during program execution. These are errors that generally cannot be recovered from and should lead to the program ending.

As it may...