Thursday, February 22, 2024

Top 20 Abstract Class and Method Interview Questions and Answers in Java

Both abstract class and abstract methods are very important concepts in core Java and every Java developer should have good understanding of what they are, when to use them and how to use them. They are also very popular on core Java job interviews as well as on Oracle Java certifications e.g. OCAJP or OCPJP. You will often find a lot of code based questions testing essential core Java concepts based upon abstract class and methods in the real exam. All good mock exam simulators e.g. Whizlabs and Enthuware contains a lot of questions testing and explaining these key concepts. In this article, I have collated some of the frequently asked questions about abstract class and abstract methods in Java. You can review these questions before going for Java interview, both telephonic and face-to-face round. They are also very useful if you are preparing for Oracle Java certification e.g. OCAJP.

Thursday, February 1, 2024

Top 6 books to learn Java Virtual Machine, Garbage Collection, and Performance [UPDATED]

In the last couple of years, I have seen a trend of many Java developers wants to learn more and more about JVM internals and how Java Virtual Machine and its different component works. This trend was not so strong in the last decade, but with more and more focus on concurrency, performance, and scalability, Java developer is exploring JVM internals, Garbage collection, and Performance tuning in more detail. Unfortunately, there are not many good books to learn about JVM internals and their different components, but fortunately, we have an excellent Java Virtual Machine specification to learn fundamentals. It is also the most up-to-date reference because Java and JVM are kept changing, especially after Java 10.