50+ Core Java and Java EE developer Job Interview Questions and Answers

Core Java Job Interview Questions and Answers

Java Job Interview Questions and answers on multi-threading Q. What is the difference between intrinsic and explicit locks in Java? Why is synchronization important?  Q. How do Java threads communicate with each other?  A very common Java job interview question to determine your ability to code and write multi-threaded program is: Printing odd and even numbers with two threads printing odd and even numbers with two threads and a blocking queue Printing odd and even number using wait & notify to communicate between threads. More multi-thread coding and thread pools Java multi-threading interview questions and answers - coding   Using the Java ExecutorService framework Java 5 Executor Framework - why use thread pools? Atomic operations
Java Job Interview Questions and answers on Data structures Java Collections Framework (i.e. Data structures) contains most commonly asked Java interview questions. A good understanding of the Java collection framework is required to leverage many powerful features of Java technology. Here are a few important practical questions which can be asked in a Core Java interview.
Java Job Interview Questions and answers on coding Some Java coding questions are very popular and frequently asked in Java job interviews.
Java Job Interview Questions and answers on OO concepts Java is an Object Oriented language. If you don't tackle these questions well enough with good examples, your chances of getting through an interview will be very slim. Q. Why favor composition over inheritance in Java OOP? is a very popular interview question. Q. How to create a well designed Java application? Q. When to use an abstract class over an interface?

Why do many Java developer resumes fail to make an impression?
Tip #1 Resumes are scanned and not read. When you write a resume, put yourself in prospective recruiter's shoes.
Tip #2 If first page of your resume is not attractive enough, most likely that your resume will not be read further.

Enterprise Java Job Interview Questions and Answers

Spring Job Interview Questions and Answers Spring is a very popular framework, and you will be quizzed on -- What do you understand by the terms Dependency Inversion Principle (DIP), Dependency Injection (DI) and Inversion of Control (IoC) container?, etc.
Hibernate Job Interview Questions and answers Hibernate is a poplar ORM framework and very poplar with the interviewers -- How will you configure Hibernate?, What is a Session? Can you share a session object between different threads?, Explain hibernate object states? Explain hibernate objects life cycle?, etc
Java Web Services Job Interview Questions and answers What are the different integration styles? What are the differences between SOAP WS and RESTFul Web Service? Which one would you choose? Why would you favor Web Services over RMI/CORBA/DCOM, etc?

Judging your Java development experience with open-ended questions

Java Job Interview Questions on Software architectures  Good calibre candidates have the ability to look at the big picture and drill down into details. The line between software development and software architecture is a tricky one. Regardless of you are an architect, developer, or both, one needs to have a good understanding of the overall software architecture.

Career Making Tips

How to choose from multiple Java job offers? In Java/J2EE career forums, interview candidates often ask how to choose from multiple job offers? This is not an easy decision to make and often this dilemma is made worse due to not asking the right questions about the position or role at the interview.
How to become a software architect? In industry specific forums, I often see questions like “what certification do I need to do to become an architect?”. The simple answer is that you don't need a certification to become an architect. It may help, but there is a lot more to it to become an architect.

JavaScript and Unix Job Interview Questions and Answers

Java and JEE Tutorials

Java, JEE, JSF, Spring, and Hibernate Tutorial Hands-on experience matters a lot, and here are a few Java tutorials that will get you started with Java, JSF, Spring, Hibernate, Web Services, eclipse, maven, and HSQLDB. These tutorials can also give you the much needed confidence at the Java job interviews.

How to prepare for your Java developer job interviews?
Tip #1 Know your resume. Many questions will be sparked from your resume.
Tip #2 Revise the core concepts. Language/Specification fundamentals and coding.
Tip #3 Revise the key areas. How to detect thread safety issues?, analyze performance bottlenecks?, etc