Java Interview Questions for Experienced Developers

By Indeed Editorial Team

Published June 10, 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

A clear understanding of Java and its applications is an important skill for developers because this programming language helps different applications and websites function. Companies typically hire experienced Java developers to create products and platforms that are secure, reliable, and swift. If you're interested in advancing your career as a Java developer, recruiters may ask you to answer interview questions that test your knowledge about the language and its application. In this article, we provide some sample Java interview questions for experienced developers, including example responses that can help you succeed in your interview.

General Java interview questions for experienced developers

Here are some java interview questions for experienced developers that a recruiter or employer may ask at the beginning of the interview to understand your interests and determine your suitability for the role:

  • Can you please tell me about yourself?

  • What made you interested in learning Java?

  • Can you tell us what your long-term goals are?

  • What do you hope to gain from this position, and how do you measure success in this role?

  • What are your salary expectations for this role?

  • How essential is teamwork to you in this role?

  • What is the most rewarding aspect of your job?

  • Tell me about a time you anticipated and prevented a problem before it happened.

  • Describe a situation where you made a mistake on a project. How did you handle it?

  • How do you prioritize your time when you're responsible for multiple projects?

Related: 19 Common Interview Questions and Answers

General interview questions about your experience and background

Here are some general questions about your education and professional background that you may encounter when attending your interview:

  • Which university did you attend?

  • Tell me about a time you made a difficult decision? What inspired your action, and how did you handle the consequences?

  • What is one important lesson you've learned in your career?

  • How did your educational background and experience in this area prepare you for this role?

  • Did you participate in any other form of training outside of traditional university education?

  • What course or courses did you find most valuable during your pursuits at university?

  • Please tell me about a particular project you worked on in your previous role that you're specifically proud of.

  • Do you have an interest in pursuing further education?

  • What did you like the least about your previous role?

  • What was a typical day like in your previous role?

  • How do you handle new projects? Please walk us through your work process.

  • What teams do you anticipate working with, and how do you facilitate collaboration?

  • What tools have you found most helpful in your career and why?

  • What skills do you think are the most important for the role you're interested in?

  • Please tell me about some innovative ideas you can contribute to this role?

Related: How to Write a Software Developer Resume (With Steps)

Technical Java interview questions for experienced developers

Hiring managers often spend a lot of time asking technical questions relating to your preferred role. Your response to these questions can help them determine if you possess the knowledge to perform efficiently. Here are some examples of technical questions you may encounter during your interview:

  • What is the difference between a Java Development Kit (JDK), Java Runtime Environment (JRE), and Java Virtual Machine (JVM)?

  • Java is a platform-independent programming language. What makes it so?

  • Is Java 100% object-oriented? Can you provide reasons for your answer?

  • What is a constructor in Java, and how does it differ from a method?

  • Why is public, private, and protected class significant?

  • What do you understand about the term ‘abstract class'?

  • What is a garbage collector in Java, and when is it used?

  • How can you implement a thread? Which method is most advantageous?

Sample answers to common interview questions for experienced Java developers

You can review these example interview questions with their sample answers to learn how to can frame your responses to suit these frequently asked interview questions:

What is the difference between JDK, JRE, and JVM?

Recruiters often ask this question to determine your knowledge of software development kits and the Java environment. You can respond to this question by providing a brief definition of the different terms and outlining the relationship that exists between them.

Example answer: "JDK, JRE, and JVM are essential components that facilitate the usage of Java. JDK, which means Java Development Kit, is a tool that allows the developer to collate, document, and package Java programs that the JRE and JVM can execute. JRE, also called Java Runtime Environment, is a prerequisite environment that makes it possible to run Java bytecodes. JVM, also called Java Virtual Machine, is a specification that facilitates the JRE where you implement bytecode."

Related: How to Be an Android App Developer (With Job Descriptions)

Java is a platform-independent programming language. What makes it so?

Recruiters may ask you this question to test your basic knowledge of Java. To answer this question, you can give a simple explanation of the features that enable Java to perform seamlessly on different platforms. You can also provide a brief insight into how the feature helps execute the same program on various platforms.

Example answer: “Java's bytecode makes it a platform-independent language as it enables developers to compile and run the program on one platform and execute it on a different platform. Java uses a virtual machine that takes care of the difference between the bytecodes for the other platforms involved.”

Is Java 100% object-oriented? Can you provide reasons for your answer?

In Java, an object is a standard component that has several uses. This question can allow you to display your understanding of this crucial concept by clearly defining the reasons behind your response.

Example answer: “Java uses eight kinds of primitive data types, which include boolean, byte, char, int, float, double, long, and short. These data types are not objects. As such, it's accurate to say that Java is more than just an object-oriented language.”

Related: What Are the Types of Interview Formats?

What is a constructor in Java and how does it differ from a method?

Constructors and methods play significant roles in creating and using objects in Java. Your response to this question may signal your level of expertise to the hiring manager, as objects perform a vital role in executing any project.

Example answer: “In Java, a constructor is a method that uses data to create value. Typically, constructors return only class variables, have the same name as the class itself, and rely on a new operator to invoke it. A method is different because it has its own name, a return type, and usually relies on a dot operator to invoke it.”

Why is public, private, and protected class significant?

A clear definition of the different classes in Java can signal your level of expertise with the language to the recruiter. You can review the following definitions to help prepare a direct answer to this question.

Example answer: Public, private, and protected classes play different roles in Java. A public class is a visible field accessible to any class in any package, while a private class is a field accessible to the class that owns a certain feature. The private variables or methods work when the same type declares the method or variable. In comparison, a protected class can interact with all members in the same package and all subclasses of the class that owns the feature.

Related: How to Prepare for a Job Interview

What is a garbage collector in Java, and when is it used?

This question seeks an answer that offers a basic definition of a garbage collector and its significance in building a program using Java.

Example answer: “A garbage collector analyzes a program to identify and remove objects. You can reclaim and reuse these resources from the garbage depending on how useful they are to your needs.”

How can you implement a thread? Which method is more advantageous?

A thread typically makes it possible for an application to perform multiple functions at the same time. The hiring manager may ask you this question to determine how well you can manage several projects and utilize the company's resources. You may respond by providing a brief explanation of the thread function and its application.

Example answer: There are different ways to run a thread in Java. For example, you can run an interface inherited from the Thread class. A runnable interface is often advantageous when running multiple inheritances as it's typically the only interface that can help.

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