Blog Archives

01: jvisualvm tutorial to sample Java heap memory

Java does not have a sizeof operator like C++ does. Java uses automatic memory management known as the Garbage Collection, hence it is not that important to evaluate size of various objects. But, for the purpose of learning & fixing any potential memory issues, I have used “jvisualvm”, which is…

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02: jvisualvm to detect memory leak – a quick tutorial style Java demo

This is a companion post to 8 Java Memory Management Interview Q&A demonstrating a memory leak scenario step by step with jvisualvm, which is a free profiling tool that gets shipped with JDK. Step 1: Code that causes memory leak Here is a sample code that causes memory leak. It…

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04: Java primitives & objects memory consumption

Q1. How much memory space does a primitive type int occupy in Java? A1. 4 bytes. Q2. Java objects get stored in the heap memory space, but how about the primitive variables? A2. It depends. 1) Primitives defined locally would be on the stack.

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06: 10+ Atomicity, Visibility, and Ordering interview Q&A in Java multi-threading

Q1. Why is it important to understand the difference between the “JVM memory model” and the computer “hardware memory model”? A1. 3 reasons why it is important to understand the JVM memory model and computer hardware memory model are: 1) JVM memory model and the physical hardware memory model architectures…

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3 Java class loading interview Q&As

Q1. What do you know about Java class loading? Explain Java class loaders?
A1. Class loaders are hierarchical. Classes are introduced into the JVM as they are referenced by name in a class that is already running in the JVM. So, how is the very first class loaded? The very first class is specially loaded with the help of static main( ) method declared in your class.… Read more ...



5 JMX and MBean interview questions & answers

Q1. What is a JMX? What are the key components of JMX? A1. JMX stands for Java Management Extensions (JMX), which is a technology to monitor and manage any Java applications are running in either a local or a remote Java Virtual Machine (JVM). 1) MBeanServer, which acts as a…

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9 Java Garbage Collection interview questions & answers

Java Garbage Collection interview questions & answers to ascertain your depth of Java knowledge in building industry strength Java applications. Determining optimal Garbage Collection (GC) settings is critical to achieve high throughput & low latency. Q1. In which part of memory does Java Garbage Collection (i.e. GC) occur? When does…

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Java Developer & Architect Interview Q&As

Java & Big Data Tutorials

Prepare to fast-track & go places

FAQs are marked with 🔥 as some questions are not only more popular with the interviewers, but also required to build robust systems. If you are an interviewer, cover well rounded topics to judge real experience.

Don't be overwhelmed by the number of questions as the technology stacks are so vast. The quality of the answers you provide to some of the key technical & open-ended questions along with your soft skills & attitude will go a long way in getting the job offers.

Note: Some Q&As belong to more than one category.
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