Java Interview Questions

http://www.journaldev.com/2366/core-java-interview-questions-and-answers

I have written a lot of posts for interview questions in java, this is a placeholder for all those posts.

1. Core Java Interview Questions and Answers

   Core Java is the starting point of any Java interview. Whether you are fresher or experienced in java, having a strong grip on Core Java is very important to clear the interview. This article lists down some of the commonly asked core java interview questions with answers.

2. Java Collections Interview Questions and Answers

   Collections are core components of Java programming language and hence widely used in interview questions. The post contains 40 questions on java collections to make sure all the topics are covered and help you in impressing your interviewer.
   I also recommend to check out java collections tutorial to have a deep knowledge of Collections in java.

3. Java String Interview Questions and Answers

   Everybody uses String and usually java interview starts with some tricky questions on Java String. This post contains 21 questions with detailed answers for String in java.

4. Java Multi-Threading and Concurrency Interview Questions

   Multithreading and Concurrency is a hot topic in java interviews. Whether you are new to Java or an expert, its good to have good knowledge on Threads in java and this post covers 30+ interview questions for Java Threads.
   I also recommend you to read Java Thread Tutorial to gain good knowledge on Threads.

5. Java Exception Handling Interview Questions

   Exception Handling is one of the tricky area and Java provides a robust and object-oriented approach for exception handling. There are Exception, Error and Throwable at the root of Exception Handling. I have seen so many guys who are confused in checked, un-checked and runtime exceptions. Here you will go through a list of 15 questions entirely related to Exception Handling in Java.
   I would also advice to go through Java Exception Handling Tutorial before jumping into interview questions directly.

6. Difference between JDK, JRE and JVM

   You should know about java virtual machine, runtime environment and java compiler. A post dedicated to explain these and list out their differences.

7. Java Classloaders

   If you consider yourself an expert in java, be prepared to face some questions on Java Classloader. A comprehensive post providing detailed explanation of different types of java classloaders, how and when we should write our own classloaders with example programs.

8. Difference between Abstract Class and Interface

   Abstract classes and interfaces are used in java for providing contract but what is the difference between them and when should we use interface over abstract class and vice versa is a great design question and asked a lot in java interviews. This post provides all the differences between abstract class and interface and when should we use interface over abstract class and vice versa. The post also explains how to use abstract class and interface both in conjunction to create a flexible design for providing contract for subclasses. I also recommend to read java abstract class and interface in javatutorials.

9. Why Java Doesn’t support multiple inheritance and Composition vs Inheritance

   One of the mostly asked question is why java doesn’t support multiple inheritance and why should we prefer composition over inheritance. A post with detailed explanation of multiple inheritance and issues with inheritance that make composition a better approach.

10. Java Tricky Programming Questions

    Some tricky questions to test your programming skills, also check out java tricky code snippets.

11. Java 7 Catch Block

    Java 7 catch block has been improved to catch multiple exceptions in a single block, a good improvement for making our catch block code small when we needed to catch a lot of exceptions.

Java EE Interview Questions

12. JDBC Interview Questions and Answers

    If you are working on Enterprise applications, I am sure that JDBC API is a part of it. JDBC API provides database connectivity for relational databases, such as MySQL and Oracle.
    This article go through a collection of 40+ interview questions related to JDBC API from basic Connection to DataSource to Connection Pooling. It will help you in interviews for questions related to JDBC API and how to effectively use it.
    If you are new to JDBC or you have a lot of experience, I would still suggest you to go through JDBC Tutorial to make sure you have covered all the core parts of it.

13. Servlet Interview Questions with Answers

    Servlets are one of the hot topics of Java Enterprise Edition interview questions. This post contains a list of 50 servlet interview questions with answers in detail. A must have bookmarked post because I will keep on adding more questions in future.

14. JSP Interview Questions and Answers

    JSP is the integral part of Java EE and if you are giving interview for web developer, then having good knowledge of JSP technology is very important. This post contains a list of 35 JSP interview questions with answers. Please make sure to bookmark it because I will be keep on adding more to the list in future.

15. Struts Interview Questions and Answers

    Struts2 is one of the modern Java Web Application framework. This article contains a list of 30 questions that covers most of the important components of Struts2 framework.

16. Spring Interview Questions and Answers

    Spring Framework is most widely used Java EE framework. It’s built on core principles of “Dependency Injection” and “Aspect Oriented Programming”. This post contains more than 45 questions related to Spring Framework, Dependency Injection, Spring AOP, Spring JDBC, Spring MVC Framework and some common tasks such as file uploading, localization etc. A good post to go through before any Java EE interview.

17. Hibernate Interview Questions and Answers

    Hibernate is the best java based ORM tool in the market. It’s used a lot in most of the enterprise applications to overcome the shortcomings of JDBC. One of the best part with hibernate is the flexibility of configuration using XML, JPA annotations as well as through code. So it’s always a plus point to have Hibernate in your resume. Whether you are experienced with hibernate or newbie, these questions will help you in interview and impress your interviewer.