If you are a Java developer and looking for some awesome resources e.g. books and courses to improve your multi-threading and concurrency skills in Java then you have come to the right place. In the past, I have shared books and tutorials on Java Concurrency and Multithreading and in this article, I am going to talk about some of the best free and paid course to learn multi-threading and concurrency in Java. You can join these free courses to improve your understanding of Java Concurrency and Multithreading. It's one of the most important skills for Java developers as almost all the companies who interviews Java developers pay particular attention to his knowledge and experience in this area. If you are aiming for a job on big Investment banks like Citibank, Deutsche Bank or Barclays or in a service based companies like Infosys, TCS and Luxsoft and others, you must have a strong command on multithreading and concurrency concepts in Java.

What are Multithreading and Concurrency? Why it's important?

Executing a Java program using multiple threads is commonly known as multi-threading. This is generally done to improve throughput and performance of your application, especially if are doing a lot of CPU intensive task. Since CPU is a scarce resource but many programs leave CPU underused, by leveraging multiple threads you get an option to make full use of CPU and increase the throughput of your Java application. When Java first came into the scene, its ability to execute programs on multiple threads got the attention. The Java Programming language has built-in support in terms of

synchronized and volatile keyword for executing programs in multiple threads. Though multithreading is not easy because when the same piece of code is executed by multiple threads, a lot of data and control related issue happens e.g. deadlock, livelock, race conditions etc. It's seriously difficult to get the concurrency right at the very first time, hence a Java developer should have a good understanding of different multi-threading and concurrency concepts before writing a multi-threaded and concurrent Java application. These are the skills you generally learn on the job but nowadays people expect you to know before you come for an interview and that's where these Java courses and books can help you. They provide the much-needed foundation and real-world examples to build the thread fundamentals and other multithreading concepts and terminology.

Top 5 Courses to learn Java Multithreading and Concurrency

Without any further ado, here is my list of some of the best courses to learn multi-threading and concurrency in Java. The list includes both free and paid courses, as well courses for both beginners and experienced Java programmers, so even if you have some background, you can use these courses to fill the gaps in your learning and become a master of Java Concurrency and Multithreading. Java Multithreading This is a free course to learn multi-threading in Java and you can join it on Udemy, the biggest platform for online courses. This is a nice fundamental course which without being too much comprehensive, tells you everything you need to read and write concurrent code using Java libraries. In this course you will learn about starting and stopping threads, basic thread synchronization using the synchronized keyword, locking, thread pools, wait and notify, callable and future, and several other concurrency utilities introduced in Java 5 e.g. CountDownLatch and Semaphores. The course also discusses common concurrency patterns like Producer-Consumer and common multithreading problems like deadLock and how to avoid it while writing Java code. You will also learn a bit about interrupting Threads and using Multithreading in Swing with SwingWorker. Overall, a great course to start learning Java Multithreading and best of all, it's FREE. Multithreading and Parallel Computing in Java This is another awesome Java Concurrency and Multithreading course from Udemy but it's not free.  Its normal price is around $200 but you can get it in just $9.99 on several of Udemy's flash sale, which is almost like free. The course is exhaustive as compared to the previous course and covers more topics and patterns with some real-life examples. Apart from basics of multi-threading e.g. threads, lock, synchronization, blocking etc, you will learn about Concurrent Collections which can simplify some concurrency design patterns. For example, it's very easy to implement Producer-Consumer pattern using BlockingQueue class as compared to a normal Collection with the wait and notify as shown here. This course discusses CountDowLatch, CyclicBarrier, Blocking Queue, Delay Queue, PriorityQueue, Exchanger, and concurrent maps like ConcurrentHashMap. Apart from Producer-Consumer, this course also explains Dining Philosopher Problem and demonstrate two simulation projects i.e. Student Libary Simulation and Minor Game Simulation, which will allow you to apply the knowledge you learn. The course also covers some advanced concepts like Parallel Algorithm, Fork-Join Frameworks, and MapReduce pattern. Overall a perfect course for experienced Java developer to augment his knowledge on this topic. Applying Concurrency and Multi-threading to Common Java Patterns This is an excellent course on Multithreading and Concurrency, particularly for experienced Java developers. In this course, instructor Jose Paumard explains how to write correct multi-threaded code using Java APIs. In this course, you will learn all the threading fundamentals you will need to write production quality multi-threaded code in Java. You will learn about the problems of concurrent programming on multicore CPU e.g. deadlock, race conditions, livelock and data corruption. Next, you will learn how your application reads data from main memory and CPU caches and how false sharing can cause slower performance. Finally, you will learn about Java Memory Mode and the notion of happens-before, the most important concept from Java programs point of view. In short, a fantastic course to fill gaps in your Java Concurrency and Multithreading knowledge. You can join this course along with reading Java Concurrency in Practice book by Brian Goetz and team to get the best of both worlds. Efficient Java Multithreading with Executors This is another nice course to learn advanced Java multithreading on Udemy. This course particularly focuses on Executor framework which was introduced Java 5 and take away pain and issues of creating and managing threads from the developer. If you have worked in a multi-threaded application before then you know that creating new threads at the time of request processing can slow you down and that's why it's better to use a pool of thread to process the request. Java solves this problem by introducing Executor framework in JDK 1.5 which provides infrastructure and API you need to create and manage a thread pool. Apart from Executor Framework, you will also learn about some basics of threading e.g. naming threads for debugging, terminating threads and handling the uncaught exception, scheduling task etc. This is the classic Java concurrency course from a Java Champion and renowned Core Java trainer, Dr. Heinz M. Kabutz. This is one of the most comprehensive and advanced courses on Java Concurrency and a must join for experienced professionals, particularly those who are working in high-performance domains. The course is a bundle of three main materials what is relevant to someone want to master concurrency: 1. Threading Essentials 2. Data Structures 3. Extreme Java - Concurrency Perofrmance. The Extreme Java - Concurrency Performance course is loosely based on the classic book by Brian Goetz and company - Java Concurrency in Practice, but brought up to speed for modern constructs from Java 8 and 9 e.g. lambdas, fork-join pool, Phaser and other advanced constructs. In short, an advanced course for Java developers who are serious about Concurrency and Multithreading skills. That's all about some of the best courses to learn Multithreading and Concurrency in Java. I have included both free and paid courses for your reference, you can choose whatever you like. Sometimes starting with a free resource is a good idea, but I would suggest with the course you liked. As you may know, the multi-threading and concurrency is very useful skill and there are a lot of exciting opportunities for developers who understand this better, particularly in large investment banks. If you are looking for your next job the time and money invested in learning Concurrency and Multithreading concepts will reap you good rewards in future. Other Java and Spring Articles you may like How Spring MVC works internally in Java? 10 Things Java Developer should learn in 2018? 10 Frameworks Java and Web Developer Should learn 10 Essential Testing Tools for Java developers 10 Tips to become a better Java Programmer in 2018 7 Reasons to use Spring for REST API development in Java 10 Tools Java Developer Should Learn in 2018 10 Books Every Java Developer Should Read in 2018 Thanks for reading this article so far. If you like these Java Multithreading and Concurrency courses then please share with your friends and colleagues. If you have any questions or feedback then please drop a note.