Java Coding Problems

Java Coding Problems

This is the code repository for Java Coding Problems , published by Packt.

Improve your Java Programming skills by solving real-world coding challenges

What is this book about?

This book covers the following exciting features:

If you feel this book is for you, get your copy today!

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Instructions and Navigations

All of the code is organized into folders. For example, Chapter02.

The code will look like the following:

public Map<Character, Integer> countDuplicateCharacters(String str) {

   Map<Character, Integer> result = new HashMap<>();

   // or use for(char ch: str.toCharArray()) { ... }
   for (int i = 0; i<str.length(); i++) {
      char ch = str.charAt(i);
      result.compute(ch, (k, v) -> (v == null) ? 1 : ++v);

   return result;

Following is what you need for this book: If you are a Java developer who wants to level-up by solving real-world problems, then this book is for you. Working knowledge of Java is required to get the most out of this book.

With the following software and hardware list you can run all code files present in the book (Chapter 1-13).

Software and Hardware List

Chapter Software required OS required
1-13 JDK Windows, Mac OS X, and Linux (Any)

We also provide a PDF file that has color images of the screenshots/diagrams used in this book. Click here to download it.

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Get to Know the Author

Anghel Leonard is a Chief Technology Strategist with more than 20 years of experience in the Java ecosystem. In his daily work, he is focused on architecting and developing Java distributed applications that empower robust architectures, clean code, and high performance. He is also passionate about coaching, mentoring, and technical leadership.

He is the author of several books, videos, and dozens of articles related to Java technologies.

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