Book Image

Learn Java with Projects

By : Dr. Seán Kennedy, Maaike van Putten
5 (3)
Book Image

Learn Java with Projects

5 (3)
By: Dr. Seán Kennedy, Maaike van Putten

Overview of this book

Learn Java with Projects stands out in the world of Java guides; while some books skim the surface and others get lost in too much detail, this one finds a nice middle ground. You’ll begin by exploring the fundamentals of Java, from its primitive data types through to loops and arrays. Next, you’ll move on to object-oriented programming (OOP), where you’ll get to grips with key topics such as classes, objects, encapsulation, inheritance, polymorphism, interfaces, and more. The chapters are designed in a way that focuses on topics that really matter in real-life work situations. No extra fluff here, so that you get more time to spend on the basics and form a solid foundation. As you make progress, you’ll learn advanced topics including generics, collections, lambda expressions, streams and concurrency. This book doesn't just talk about theory—it shows you how things work with little projects, which eventually add up to one big project that brings it all together. By the end of this Java book, you’ll have sound practical knowledge of Java and a helpful guide to walk you through the important parts of Java.
Table of Contents (22 chapters)
1
Part 1: Java Fundamentals
9
Part 2: Object-Oriented Programming
15
Part 3: Advanced Topics

Concurrent collections

Multi-threaded environments are important for performance, but in any multi-threaded environment, data integrity becomes an issue to consider. Imagine a situation where you have several threads interacting with a shared data structure, such as an ArrayList or HashMap. While one thread might be trying to read data from the structure, another could be writing to it. This can lead to data inconsistency and other types of errors.

One common problem that arises in such situations is known as a concurrent modification exception. This occurs when one thread is iterating over a data structure, and another thread attempts to modify it. Java recognizes that this can cause inconsistencies and throws an exception to prevent this dangerous operation.

Consider the following example, where a HashMap is being used:

Map<String, String> languageMap = new HashMap<>();languageMap.put("Maaike", "Java");
languageMap.put("Seán&quot...