Master the skills needed to get hired as a Java developer with these free and paid courses: including Swing, JUnit 5, and Spring Framework 6.0

The internet is flooded with Java courses, but let’s be real — a lot of them are . Too many are copy-cats of each other, teaching only the bare basics and often riddled with outdated practices.

Fortunately for you, I’ve scoured the web to uncover the cream of the crop — up-to-date Java courses (many use Java 11 or 17) that not only teach the fundamentals, but also advanced topics used in the real world: design patterns and concurrency, unit-testing with JUnit 5, GUI programming with Swing and JavaFX, and the ever-popular back-end web development with Spring 3 and Spring Boot 6.

Authored by university professors and seasoned Java professionals, many of these resources are free, with some paid gems worth every penny.

And for the other half of Java developers that prefer reading to watching, I’ve also thrown in a couple of books, some of which are considered must-read by the Java community.

I’ve categorized this Best Courses Guide (BCG) into three sections to help you navigate to what you want to learn: Beginner to Intermediate Java, Spring and Spring Boot, or Intermediate to Advanced Java.

Click on the shortcuts for more details:

• Top Picks
• What is Java?
• Courses Overview
• What Next?
• Why You Should Trust Us
• BCG Methodology

Here are my top picks. Click on one to skip to the course details:

What is Java?

Java is a high-level object-oriented programming language with one special characteristic — it is platform independent. Meaning, it can be written once and run on any operating system, from Android to Windows and MacOS.

Instead of compiling directly to machine code, it compiles to Java Bytecode, an intermediary step between pure written Java and machine code. To run the Java Bytecode, a Java Virtual Machine (JVM) for a specific operating system needs to be installed. The JVM interprets the Java Bytecode to produce machine code to be run by the operating system.

The most common use of Java among developers is in back-end development, with 38% of Java developers. And the most popular framework for back-end development is Spring.

Why Learn Java?

Java has consistently placed the 2nd to 4th spot in every language popularity ranking (excluding Domain Specific Languages like SQL): PYPL, TIOBE, StackOverflow, JetBrain, RedMonk, GitHub, SlashData, and IEEE Spectrum. With a massive developer community of 17.5 million (3 times the size of C!), to say that it’s widespread would be an understatement.

But are Java developers in demand? The answer is yes — 60% of companies plan to add Java developers in 2024. So if you’re looking to break into tech, you’ll find plenty of opportunities in the job market.

What about salary? According to Indeed, Glassdoor, and ZipRecruiter, Java developers in the US can expect an annual salary of $91K to $118K.

Courses Overview

• 8 resources are free, while 8 are paid
• 6 of the resources are geared towards beginners to Java, 4 towards Spring and Spring Boot, while 6 are for learning intermediate to advanced Java
• 6 of the resources are books, whereas the rest are online courses
• About 21.2K people are following Java Courses on Class Central.

Beginner to Intermediate Java

Best Free Course for Beginners with Certification (University of Helsinki)

The best free Java course in 2024, hands-down, is the open-source Java Programming MOOC from the University of Helsinki.

Why? Because:

• Comprehensive:
  • The course is split into two parts: Introductory and Intermediate. It’ll take you from knowing nothing about programming to remaking the classic Asteroids game. By the end of this course, you’ll have the same foundational knowledge of Java and programming as a first-year student at Helsinki.
• Hands-on Exercises:
  • You don’t learn to program by reading — you learn by doing. Thus, this MOOC offers a whopping 261 programming exercises to help you practice your coding skills, with code submission and automated feedback, something the majority of free courses don’t offer.
• Active Community:
  • Need help with an exercise? Join their official Discord server, filled with fellow course-takers and mentors.
• Free Certifications:
  • Once you have completed at least 80% of the exercises for one part of the course, you earn a certificate of completion. Thus if you complete both parts, you’ll earn two certificates.

If you’re wondering about what you’ll learn, here’s a brief overview:

• Fundamentals of programming in Java, including tools, repetition, functions, data structures (lists, arrays, strings), and file I/O
• Object-oriented programming (OOP) concepts and techniques, such as creating classes, inheritance, interfaces, and separating user interface from program logic
• Advanced Java features like streams, lambda expressions, exceptions, packages, type parameters, generics, and multidimensional arrays
• Creating graphical user interfaces (GUIs) with Java, handling events, and building multi-view applications
• Data visualization with charts, image processing, audio playback, and finally, developing an Asteroids game using Maven and third-party libraries.

If you’re planning to do the exercises (which you should), here’s a heads-up:

• To submit your code for grading, you’ll need to install their TestMyCode plugin, available for both Netbeans and Visual Studio Code (VSCode) code editors. If you’re a Mac user, using VSCode as Netbeans is a buggy mess. Also, their plugin for IntelliJ is broken, so don’t use it.
  • My recommendation is to use VSCode. Watch this beginner guide to VSCode if you need setting up.
• You can find student-completed solutions to the exercises on GitHub if you get stuck.

Institution	University of Helsinki
Prerequisites	Beginner
Workload	140–280 hours
Cost	Free
Certificate	Free

Best Freemium Learning Platform (JetBrains Academy)

Are you looking for a more interactive learning environment? Do you want to master IntelliJ IDEA, the most popular Integrated Development Environment (IDE) for Java? Then check out Hyperskill!

This freemium learning platform was created by the folks at JetBrains, the same ones that created IntelliJ IDEA, the most widely used Integrated Development Environment (IDE) for Java which itself is made in Java.

Created by the brilliant minds at JetBrains, the developers of IntelliJ IDEA itself, Hyperskill is a freemium learning platform that offers a practical and immersive learning journey. With coding exercises seamlessly integrated into IntelliJ, you’ll receive automated feedback, making your learning experience both efficient and enjoyable.

Hyperskill offers multiple learning tracks tailored to your interests and goals. Here are a few noteworthy tracks:

• Introduction to Java (≈42 hours)
  • New to programming and don’t know where to start? Start here!
  • You’ll master the basics of Java programming, including Object-Oriented Programming, error handling, and I/O. By the end, you’ll be ready to tackle more advanced courses
• Java Desktop Application Developer (≈171 hours)
  • Want to make GUI desktop applications with Swing? In addition to GUI programming, you’ll also explore multithreading, use regular expressions to parse strings, and also understand how randomness works in Java
• Java Backend Developer (Spring Boot) (≈173 hours)
  • Become a back-end developer with Spring! You’ll learn how to design and construct web applications with Spring Boot, deal with databases, create RESTful APIs, and much more.

By the way, lessons are shared between paths, so you won’t have to repeat course material if you decide to switch paths or have already completed some of the content. Plus, if you’re already familiar with certain topics, you can take a skill placement assessment to skip ahead and focus on new concepts.

All of these features are available in the free plan. However, if you opt for a paid subscription, you’ll gain access to unlimited retries, real-world portfolio projects, and best of all, verified certificates of completion, to give you a competitive edge when applying for jobs.

Institution	JetBrains Academy
Provider	Hyperskill
Prerequisites	Beginner
Workload	50–200 hours per track
Cost	Free
Certificate	Paid

Best Java High School Summer Program NYC course with Live Sessions (Noble Desktop)

If you prefer instructor-led learning, Noble Desktop’s Java High School Summer Program NYC offers real-time feedback and accountability that pre-recorded courses can’t match. The program is ideal for high school students (ages 13-18). College students may also attend.

What I find interesting is that this program runs both in-person (NYC campus) and online (Zoom). Even if you’re attending online, you’ll have individual attention and can see other students in the classroom. You’ll be able to interact with instructors, receive feedback, and ask questions during sessions. Plus, you’ll get access to class recordings and workbooks – pretty helpful for catching up if you miss a class or reviewing what you learned.

Key Benefits

• Small class sizes (8-15 students)
• Certificate of completion to showcase achievements
• Free retake within one year
• Detailed class files with real-world projects
• Can also upgrade to the Computer Science High School Summer Program NYC

Noble Desktop knows what they’re doing – they’ve been around for over three decades providing instruction with industry experts. So you can rest assured your mentorship will not be with someone who just finished the course. Don’t take my word for it – student reviews on Yelp and Google praise their practical approach and instructor quality.

What You’ll Learn

• Programming basics, including variables, data types, and operators
• Control flow techniques like conditional statements, loops, and function declarations
• Manipulate data with arrays, strings, and dictionaries for processing
• Object-oriented programming concepts such as encapsulation and polymorphism
• Write recursive functions and apply recurrence relations to solve problems
• Interpret large programs while developing a programmer’s mindset for problem-solving
• Write algorithms in both procedural and object-oriented paradigms
• Input and output operations, including file handling, string formatting, and redirecting output

Flexible Schedule Options

• 1 week full-time (weekdays)

Provider	Noble Desktop
Level	Beginner
Workload	50 hours
Rating	4.8/5.0 (Yelp) and 5.0/5.0 (Google)
Certificate	Paid

Best Paid Book for Beginners (Kathy Sierra)

Do you love reading? I love reading. But even if you don’t, you’ll still love reading Head First Java.

Why? Mainly because:

• Aimed towards beginners:
  • It assumes very basic knowledge of programming (limited to looping and if/else logic)
• Comprehensive:
  • You’ll have a working understanding of programming and Java development by the end
• Fun and Quirky:
  • The book uses a friendly conversational tone, unafraid of coming off as silly and playful, to keep things engaging
• Tons of Visuals and Examples:
  • Lots of visual gags that help make abstract, boring concepts memorable. For example, imagine an abstract method as a head without a body
• Social Proof:
  • Many renowned Java experts have praised the book, from university PhDs, to Java champions at Silicon Valley, and even the former CEO of Sun Microsystems.

Some of the topics you’ll cover in the book include:

• Java fundamentals:
  • Core Java concepts and object-oriented programming principles, including inheritance, polymorphism, interfaces, and abstract classes
• Writing and testing Java programs:
  • Designing, writing, exception-handling, and testing Java applications using the Java API and libraries
• Advanced Java concepts:
  • Static methods and variables, the object lifecycle, generics, collections, lambdas, streams, and functional programming techniques
• GUI programming with Swing:
  • How to build graphical user interfaces using the Swing toolkit, creating interactive applications with buttons, graphics, animations, and event handling
• Networking and concurrency:
  • Creating client-server applications that communicate over a network. Additionally, multithreading and handling common concurrency issues
• Additional topics and best practices:
  • Other essential topics, including exception handling, file I/O, object serialization, and best practices for writing clean, efficient, and maintainable Java code.

So, if you find the previous courses to be a chore, try giving this book a read — I’m sure it’ll crack you a few laughs by the time you’ve finished!

Publisher	O’Reilly
Provider	Independent
Authors	Kathy Sierra, Bert Bates, Trisha Gee
Prerequisites	Basic programming experience
Workload	N/A (752 pages)
Rating (Amazon & Goodreads)	4.7/5.0 (237) & 4.7/5.0 (8)
Cost	Paid
Certificate	None

Best Paid Book for Programmers (Cay Horstmann)

If you already know how to program and want to cut to the chase, then you’re the prime audience for Core Java for the Impatient, 3rd edition.

Written by Cay S. Horstmann (famous for his classic two-volume Core Java), this paid book is a complete yet concise introduction to the Java programming language and key APIs. It introduces all the key features of Java quickly and efficiently without getting bogged down in overly detailed explanations — no writing linked lists or web server by hand!

Consisting of 15 chapters of content, you’ll cover:

• Core Java: Fundamental Programming Structures, Object-Oriented Programming, Interfaces, Lambda Expressions, Inheritance, Reflection
• Error Handling & Logging: Exceptions, Assertions, Logging
• Advanced Programming Concepts: Generic Programming, Collections, Streams, Concurrent Programming
• Java APIs: Processing Input/Output, Annotations, Date and Time API, Internationalization
• Java Development: Compiling, Scripting, Java Platform Module System.

At the end of each chapter, you’ll find coding exercises for you to engrave what you’ve just learned into memory. No coding solutions are provided, but you can find student-completed solutions on GitHub.

Publisher	Addison-Wesley Professional
Provider	Independent
Author	Cay S. Horstmann
Prerequisites	Familiarity with programming
Workload	N/A (506 pages)
Rating (Amazon & Goodreads)	5.0/5.0 (56) & 4.2/5.0 (62)
Cost	Paid
Certificate	None

Best Free Hands-On Java Project Tutorial (Marco Behler)

So, you’ve dabbled in Java and feel like you’re ready for a new challenge.

Here’s a suggestion: why do a fun project? And not just any run-of-the-mill to-do list project either. How about making a clone of Google Photos in Java?

Lucky for you, Marco Behler, a Developer Advocate at JetBrains, has put together a free YouTube series. You’ll build a photo management service from code to native executable, following real-world best practices like unit testing and logging. He’ll lead you through the development process with a flair of humor and energy.

But you won’t only learn the development tools. He’s going to help you develop the mindset of a true developer. You’ll learn how to tackle problems head-on and think about the consequences of your code and design decisions.

You’ll cover:

• How to properly do code reviews: ensuring the code meets requirements while maintaining positive human relationships
• Implementing parallelization with ExecutorService
• Pragmatic unit testing with JUnit 5
• Utilizing an embedded H2 database
• Implementing infinite scrolling and asynchronous file downloads without writing any JavaScript by using HTMX
• Building a native executable with GraalVM & Spring Boot.

You can find the source code for the project on GitHub here.

Channel	Marco Codes
Provider	YouTube
Instructor	Marco Behler
Prerequisites	Basic experience with Java
Workload	3–4 hours
Views	4K
Cost	Free
Certificate	None

Spring and Spring Boot

Best Free Spring 6 Learning Platform (Spring Academy)

The most popular use of Java is in back-end development, and the most popular framework for that is Spring. And what better way to learn Spring than from the creators of Spring themselves?

And lucky for us, Spring Academy recently made their pro courses completely free to anyone who signed up with their work email. Awesome!

Currently, they offer 9 courses, but what I want to highlight is their Spring Certified Professional learning path, updated for Spring 6 and Spring Boot 3. After watching their videos led by various Spring experts, you’ll gain hands-on experience through interactive in-browser coding labs equipped with a terminal and code editor. By the end of the course, you’ll have a working understanding of cloud-ready microservices applications.

Once you’re done with the course, you’ll be ready for the Spring Certified Professional exam to prove to employers that you’ll be able to spring into action with enterprise applications.

Institution	Spring Academy
Provider	Independent
Prerequisites	Familiarity with Java, Maven/Gradle, and web application development with a Servlet engine
Workload	26 hours
Cost	Free (with work email)
Certificate	Paid

Best Free Spring 5+ Course for Complete Beginners (Telusko)

If you already have your sights set on learning Spring, but don’t have any Java or programming experience, then this course is for you.

This huge 48-hour course will teach you core Java from the ground up, and then help you spread your wings by instructing you on essential tools and frameworks a modern Java developer needs: unit testing, version control, data structures and algorithms, and finally, Spring.

I’ve roughly estimated the time period for each topics for the course below:

• Core Java: 13 hours
• JUnit: 3 hours
• DSA: 5 hours
• Git: 2 hours
• JDBC, Servlet and JSP, and Hibernate: 9 hours
• Rest API Web Service: 3 hours
• Spring Framework (including JDBC, MVC, Data JPA, AOP, Security): 5 hours
• Projects with Rest API & Spring Boot MVC: 1 hour
• Java Spring Boot MongoDB Full Project: 6 hours
• Microservice: 1 hour.

Do note that the course is using Spring 5, but nevertheless the changes are minimal except for Spring Security. But if you do want to learn the latest version of Spring, Navin has an updated Udemy course.

Channel	Telusko
Provider	YouTube
Instructor	Navin Reddy
Prerequisites	None
Workload	48 hours
Views	560K
Likes	17K
Cost	Free
Certificate	None

Best Free Hands-On Spring Boot 3 Tutorial (Dan Vega)

Would you rather a shorter, more focused course where you learn by building? Then this free YouTube course Building web applications in Java with Spring Boot 3 is for you.

It’s led by Dan Vega, a renowned Spring Developer Advocate at Broadcom and a Java Champion. You’ll build a fitness application where users can track different runs, including recording the title, start time, end time, distance, and location of each run.

Here’s what you’ll cover:

1. Getting Started: Create a new Spring Boot project, setting up the development environment in IntelliJ, and writing the first piece of code
2. Building a REST API: Developing REST API using Spring MVC, including handling HTTP requests, implementing CRUD operations, and working with validation
3. Connecting to a Database: How to connect the application to a database, including using an in-memory database and a Postgres database with Docker. It also covers Spring Data JPA
4. Using a REST Client: Explore different options for making client calls to other REST services, including the REST Client and HTTP Interfaces
5. Testing: Testing the application with JUnit 5 and the testing tools provided by Spring, including unit tests, integration tests, and end-to-end tests.

Want more of where that came from? Check out Dan’s YouTube channel, he has tons of free videos and lessons on the Spring ecosystem. And if you have any Spring questions, Dan and his friend DaShaun host an Office Hour livestream every Monday, where they cover what’s new in Spring and answer Spring-related questions from viewers.

P.S: Looking for more specialized Spring courses, from Full-Stack Web Development with Spring, to Spring Security or Spring MVC? Check out my BCG Spring Boot for more offerings!

Channel	freeCodeCamp
Provider	YouTube
Instructor	Dan Vega (YT Channel)
Prerequisites	Basic to intermediate experience with Java
Workload	3–4 hours
Views	100K
Likes	2.7K
Cost	Free
Certificate	None

Best Free Course for JPA/Hibernate (Laur Spilca)

Object-Relational Mapping (ORM) allows Java developers to map Java objects (entities) to database tables, without the need of writing complex SQL queries. The Java Persistence API (JPA) provides the specification, and the most popular implementation of the JPA is the open-source Hibernate framework.

Laur Spilca is one of the foremost experts on Spring. He’s authored multiple best-seller books with over a decade of experience teaching. And you’ll learn everything you need to know to get started with Hibernate from him for free in this YouTube playlist!

In this comprehensive 13–14 hours long course, Laur covers:

• Entities:
  • How to define and work with entities, which are Java classes that represent database tables
• Relationships:
  • Different types of relationships between entities, including one-to-one, one-to-many, and many-to-many relationships
• Querying:
  • Various ways of querying using JPA/Hibernate, such as JPQL (Java Persistence Query Language), native queries, and criteria queries
• Advanced querying techniques:
  • How to use joins, subqueries, grouping, ordering, and having clauses in your queries to retrieve complex data sets
• Integration with Spring:
  • Spring Data, its relation to JDBC and JPA/Hibernate, and how it simplifies common database operations by providing an abstraction over the JPA/Hibernate implementation.

Laur has also uploaded Java and Spring related playlists on his channel, such as Spring Security Fundamentals, Reactive Spring, and Java Design Patterns. Check him out if you love his teaching style.

Channel	Laur Spilca
Provider	YouTube
Instructor	Laurentiu Spilca
Prerequisites	Familiarity with Java, JDBC, and SQL
Workload	13–14 hours
Views	31K
Cost	Free
Certificate	None

Intermediate to Advanced Java

Best Paid Book for Java Best Practices (Joshua Bloch)

There are two books highly regarded by the Java community as must-reads for Java developers. The first is Effective Java, 3rd edition by Joshua Bloch.

This is a paid book targeting intermediate to advanced Java developers who aim to write efficient, clear, and maintainable code. Bloch, a prominent figure in the Java world (he’s in Wikipedia), draws upon his extensive experience as the former chief Java architect at Google, a distinguished engineer at Sun Microsystems, and a senior systems designer at Transarc to provide 90 best practices and guidelines to follow.

Few of key principles emphasized are:

• Favoring composition over inheritance
• Favoring interfaces over abstract classes
• Minimizing mutability
• Carefully designing method signatures
• Using overloading judiciously
• Using checked exceptions for recoverable conditions, runtime exceptions for programming errors
• Synchronizing access to shared mutable data
• Preferring executors and tasks to threads.

Publisher	Addison-Wesley Professional
Provider	Amazon
Authors	Joshua Bloch
Prerequisites	Intermediate to advanced Java experience
Workload	N/A (416 pages)
Rating (Amazon & Goodreads)	4.7/5.0 (1.5K) & 4.5/5.0 (7.8K)
Cost	Paid
Certificate	None

Best Paid Book for Java Concurrency (Brian Goetz)

The second book is Java Concurrency in Practice (or JCIP), a written collaboration between multiple renowned Java engineers, architects, and developers. It’s so chock-full of valuable insights that, even after two decades, remains the go-to resource for grasping concurrency.

And while you may not be directly implementing low-level concurrency, all modern concurrency frameworks you’ll encounter (like virtual threads) have these principles baked in, so getting a solid grasp of the underlying basics will save you a ton of headaches down the road.

Some of the insights you’ll uncover from the JCIP include:

• Fundamentals of concurrency and thread safety
• Structuring concurrent applications
• Composing objects for concurrency
• Building blocks for concurrency, such as synchronizers, thread pools, and concurrent collections
• Designing concurrent libraries and measuring performance
• Advanced topics like explicit locks, atomic variables, and nonblocking algorithms
• Understanding the nitty-gritty of the Java Memory Model.

By the time you’ve finished this book, you’ll have a toolbox full of design patterns and best practices for crafting efficient, correct, and maintainable concurrent code in Java.

You can find code examples and testimonials on their companion website.

Publisher	Addison-Wesley Professional
Provider	Amazon
Authors	Brian Goetz, Tim Peierls, Joshua Bloch, Joseph Bowbeer, David Holmes, and Doug Lea
Prerequisites	Intermediate to advanced Java experience
Workload	N/A (432 pages)
Rating (Amazon & Goodreads)	4.7/5.0 (791) & 4.47 (2.8K)
Cost	Free
Certificate	None

Best Paid Book for Java Design Patterns (Eric Freeman)

Design patterns are proven, reusable solutions to common software design problems. For example, how do you create objects while hiding the creation logic, or ensure only one instance of a class is created? Design patterns provide proven solutions to these common problems.

Most companies assume that you know your design patterns, and often test you on them. Thus, having firm knowledge of the most common design patterns and how to implement them is crucial for success.

But how do you learn them? My recommendation: Head First Design Patterns, 2nd Edition. In this paid book, you’ll master object-oriented design principles and 16+ design patterns, from the ubiquitous Factory pattern to the renowned Model-View-Controller pattern. And with lots of casual, quirky humor and fun images and diagrams to boot!

The book uses Java when implementing these design patterns, so you’ll be able to follow along on your local machine.

PS: If you want a free alternative, there’s Java Design Patterns. It’s more of a reference than a guide, though.

Publisher	O’Reilly
Provider	Independent
Authors	Eric Freeman and Elisabeth Robson
Prerequisites	Intermediate to advanced Java experience
Workload	N/A (669 pages)
Rating (Amazon & Goodreads)	4.7/5.0 (1.1K) & 4.3/5.0 (8.7K)
Cost	Paid
Certificate	None

Best Free Course for Quality Assurance with Certification (Test Automation University)

Quality assurance (QA) is essential for companies to ensure their code is reliable and performs well. If you’re interested in becoming a QA tester or you’re a developer looking to improve your product’s quality for users, Test Automation University is the best free learning platform to start learning QA.

There are three comprehensive Java learning paths, each designed to teach you the language from scratch, along with the fundamentals of test automation, IntelliJ, and JUnit 5/TestNG. These paths include:

• Java Web UI Path (21–23 hours)
  • In this path, you’ll gain expertise in testing websites using powerful automated tools such as Selenium, Cucumber, and Docker. By the end of the course, you’ll be proficient in measuring the performance and load of websites, ensuring optimal user experience
• Java API Path (14–16 hours)
  • This path focuses on equipping you with the skills necessary to perform automated testing of Service and RESTful APIs. You’ll become well-versed in using popular Java libraries like REST Assured to help you efficiently test and validate API functionality
• Java Mobile Path (25–27 hours)
  • Dive into the world of mobile application testing with this path. You’ll master the use of Espresso and Appium, two industry-standard open-source test automation frameworks, to thoroughly test Android applications. Additionally, you’ll explore visual testing techniques, allowing you to capture screenshots during testing and compare them against baseline images to ensure visual consistency.

They even have a Slack channel where you can connect with fellow QA testers.

Institution	Test Automation University
Provider	Independent
Prerequisites	None
Workload	14–27 hours
Enrollments	>150K
Cost	Free
Certificate	Free

Best Paid JUnit 5 Book (Cătălin Tudose)

Though developers may grumble, unit testing is a requirement if you value your time. JUnit 5 is the industry-standard unit testing framework among Java developers. And to learn it best, learn from Cătălin Tudose’s JUnit in Action, Third Edition.

In this paid book, you’ll learn how to effectively use JUnit to write and run repeatable tests for Java applications. It’s suitable for both beginners to unit testing and anyone who wants to keep up to the latest version of JUnit.

You’ll learn:

• JUnit 5 essentials:
  • You’ll cover basic testing concepts, JUnit 5 capabilities and architecture, migration from JUnit 4 to JUnit 5, and different types and levels of testing
• Testing strategies:
  • Explore various testing strategies, including assessing test quality, using stubs for isolation, implementing mock objects, and running tests in containers with Docker
• JUnit 5 and other tools:
  • You’ll discover how JUnit 5 integrates with build tools like Maven and Gradle, popular IDEs such as IntelliJ IDEA and NetBeans, as well as CI tools like Jenkins for automating builds and maintaining code repositories
• JUnit 5 and modern frameworks:
  • JUnit 5 can also be used with modern frameworks. You’ll learn how to test the presentation layer with HtmlUnit and Selenium, test Spring and Spring Boot applications, test REST APIs, and finally test databases with JDBC, Spring, and Hibernate
• Modern software development methodologies:
  • Test-Driven Development is a recent wave, but there are other modern software development methodologies too. You’ll discover behavior-driven development and build a comprehensive test pyramid strategy encompassing unit, integration, system, and acceptance testing.

For a free alternative to the book, check out JavaBrain’s JUnit 5 Basics YouTube playlist. It should be more than enough to get you up and running.

Publisher	Manning
Provider	Independent
Author	Cătălin Tudose
Prerequisites	Familiarity with Java, Maven, and IntelliJ
Workload	N/A (525 pages)
Rating (Amazon & Goodreads)	4.5/5.0 (16) & 3.6/5.0 (23)
Cost	Paid
Certificate	None

Best Paid Course for Apache Kafka (Stephane Maarek) 

One essential tool you might be expected to know is Apache Kafka, a distributed streaming platform that is used for real-time data streaming applications. Thousands of companies, including over 80% of the Fortune 100, use Apache Kafka to collect, process, store, and analyze data at scale.

Thus, Kafka is a valuable skill to have, and the best paid course to learn Kafka as a Java developer is Stephane Maarek’s Apache Kafka Series – Kafka for Beginners on Udemy, with an excellent rating of 4.7/5.0 stars and over 225K students.

It covers:

• Apache Kafka ecosystem architecture and core concepts
• Setting up and using Kafka clusters with native binaries and CLI
• Coding producers and consumers using the Java API
• Real-world project and case studies showcasing Kafka’s applications, from movies to taxis to social media
• Overview of advanced APIs, administrative topics, and configurations.

You’ll put theory to practice on the online learning platform Stephane Maarek co-founded, Conduktor Kafkademy, through hands-on labs and exercises. It also offers free lessons, though limited in scope.

Institution	Conduktor Kafkademy
Provider	Udemy
Instructor	Stephane Maarek
Prerequisites	Basic Java programming experience
Workload	8–9 hours
Enrollments	226K
Rating	4.7/5.0 (44K)
Cost	Paid
Certificate	Paid

What Next?

Phew, so you’ve finally gotten a foothold in the world of Java programming, and perhaps some Spring under your belt. But that’s only the beginning of your journey. Here are some skills (with accompanying BCGs) that recruiters might expect you to know as a Java developer.

• Containers (Docker & Kubernetes)
• Web Development
• Data Structure & Algorithms
• Databases (SQL or noSQL)
• Git & GitHub
• Build Manager (Maven/Gradle)
• Cloud (Azure, GCP, AWS, etc)

Why You Should Trust Us

Class Central, a Tripadvisor for online education, has helped 60 million learners find their next course. We’ve been combing through online education for more than a decade to aggregate a catalog of 200,000 online courses and 200,000+ reviews written by our users. And we’re online learners ourselves: combined, the Class Central team has completed over 400 online courses, including online degrees.

Best Courses Guide (BCG) Methodology

I built this guide following the now tried-and-tested methodology used in previous BCGs (you can find them all here). It involves a three-step process:

1. Research: I started by leveraging Class Central’s database and the internet. Then, I made a preliminary selection of 2800+ Java courses by rating, reviews, and bookmarks.
2. Evaluate: I read through reviews on Class Central, Reddit, and course providers to understand what other learners thought about each course and combined it with my own experience as a learner.
3. Select: Well-made courses were picked if they presented valuable and engaging content. Selection criteria includes comprehensive curriculum, affordability, release date, ratings and enrollments.

Ultimately, I used a combination of data and my own judgment to make these picks. I’m confident these recommendations will be a reliable way to learn Java.