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Java interview questions and online tests

DevSkiller Java Coding Questions have been specially prepared by our expert team of professionals for Java developers- from junior to senior level. All of our Java coding tests are specifically tailored to ensure you find the perfect candidate, using a specific range of Java questions.

DevSkiller Java coding questions are powered by the RealLifeTesting™ methodology which works by replicating real-world scenarios for your applicants to solve. Finding your next Java developer is simple with our unique range of tests.

Technologies covered:

Programming language: Java

Java frameworks and libraries: Spring Framework, Spring Boot, Hibernate, JPA, GWT, JSF, Vaadin, Play Framework, Groovy, Spock Framework / JUnit, TestNG, Selenium and others

Build tools: Maven, Gradle

Java
SENIOR
Tested skills
Duration
111 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Core Java, I/O system, Lambda Expressions, Exceptions

Code gaps

assessing knowledge of Java, Core Java, I/O system, Lambda Expressions, Network Communication

Programming task - Level: Hard

Java | Library application - Create an application that allows the library to manage books, their borrowings and prepare some reports about books that were not returned on time. Finish implementation of the missing service methods.

junit
MIDDLE
Tested skills
Duration
64 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of JUnit, QA

Code gaps

assessing knowledge of JUnit, JUnit4, QA, JUnit 5, Java

Programming task - Level: Medium

QA | JUnit | ATM Service | Authentication and deposit validation - Write test cases to verify the Automated Teller Machine (ATM) software.

Java
MIDDLE
Tested skills
Duration
75 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Core Java, Java, Serialization, Date and Time, Generics

Code gaps

assessing knowledge of Core Java, Java, Memory Management, Network Communication, Lambda Expressions

Programming task - Level: Medium

Java | Library application - Creating an application allowing the library to manage books and their borrowings. Your current task is to finish the implementation of missing service methods.

java
MIDDLE
Tested skills
Duration
58 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Core Java, Java, Stream API, I/O system, Date and Time

Code gaps

assessing knowledge of Core Java, Java, Network Communication

Programming task - Level: Medium

Java | Azure | Production summarizer - Create an Azure function. Your current task is to finish implementation of production summarizer returning information about how many cars were produced by a particular plant.

Java
MIDDLE
Tested skills
Duration
104 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Spring Boot

Code gaps

assessing knowledge of Core Java, Exceptions, Java, Generics, I/O system

Programming task - Level: Medium

Java | Couchbase, Spring Boot | Card Payments - Create a card payment processing microservice. Finish the implementation of saving payment data into Couchbase and communicate with other services.

Java
JUNIOR
Tested skills
Duration
49 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Core Java: Network Communication, Generics, Memory Management

Code gaps

assessing knowledge of Core Java: Collections, Memory Management, Generics

Programming task - Level: Easy

Java | Currency Exchange - Complete the implementation of the Currency Exchange app, which is responsible for managing exchange rates and exchanging the currencies.

Java
JUNIOR
Tested skills
Duration
37 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Core Java, Lambda Expressions, Memory Management

Code gaps

assessing knowledge of Core Java, Java, Memory Management, collections, Lambda Expressions

Programming task - Level: Easy

Java | Library Application - Creation of an application allowing the library to manage their books stock. Task goal is to finish the implementation of missing service methods.

junit
MIDDLE
Tested skills
Duration
66 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of QA, Testing, Unit-Testing, Manual Testing

Code gaps

assessing knowledge of JUnit 5, Java, QA

Programming task - Level: Medium

QA | JUnit | ATM Service | Authentication and deposit validation

Selenium
MIDDLE
Tested skills
Duration
48 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of QA, Selenium, .NET, C#

Code gaps

assessing knowledge of Java, QA, Selenium

Programming task - Level: Medium

QA | .NET, Selenium | Data extraction - Implement methods in class SeleniumTask.SeleniumExecutor to pass successfully all tests.

junit
MIDDLE
Tested skills
Duration
73 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java and QA

Code gaps

assessing knowledge of Java and QA

Programming task - Level: Medium

QA | Java, JUnit | Vending Machine - Write unit tests for the verification of a Vending machine.

Java
MIDDLE
Tested skills
Duration
69 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of API, Java

Code gaps

assessing knowledge of Java, Java Stream API, Streams

Programming task - Level: Medium

Java | Standard Search Engine - Implement engine for product searching based on simple and compound predicates.

Java
SENIOR
Tested skills
Duration
78 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java

Code gaps

assessing knowledge of Java

Programming task - Level: Hard

Java | Precomputation Queue - Implement priority queue which will be used on several nodes to asynchronously precompute statistics about product sets.

Java
MIDDLE
Tested skills
Duration
97 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java

Code gaps

assessing knowledge of Java

Programming task - Level: Medium

Java | Precomputing Search Engine - Implement the optimized engine for the product search, based on the precomputation task to precompute the results for any set of the options.

Java
SENIOR
Tested skills
Duration
71 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Multithreading

Code gaps

assessing knowledge of MongoDB

Programming task - Level: Hard

Java | Circuit Breaker and Retry pattern - Implement circuit breaker, fallback and retry pattern in microservice architecture.

Android
SENIOR
Tested skills
Duration
48 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Android

Code gaps

assessing knowledge of Android, Java, ProGuard

Programming task - Level: Hard

Android | Java | ProGuard configuration - Implement the ProGuard Configuration to remove developer's code from the code base - at compile time.

Java
MIDDLE
Tested skills
Duration
39 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java

Code gaps

assessing knowledge of JUnit 5, Java, QA

Programming task - Level: Medium

Java | JUnit | Flight Manager - Implement the missing features into the application responsible for managing flights data.

Java
MIDDLE
Tested skills
Duration
57 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Spring Boot

Code gaps

assessing knowledge of PostgreSQL, SQL

Programming task - Level: Medium

Java | Spring Boot | Items Retriever Microservice - Implement a microservice to retrieve items from the shopping system.

Java
JUNIOR
Tested skills
Duration
39 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Spring Boot, JPA

Code gaps

assessing knowledge of Java

Programming task - Level: Easy

Java | Spring Boot with JPA queries - Implement SQL queries to find the best streaming platform.

Java
SENIOR
Tested skills
Duration
78 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of GIT

Code gaps

assessing knowledge of Java

Programming task - Level: Hard

Java | Internet Banking System Decryption Service - Implement methods related to cryptography.

Java
MIDDLE
Tested skills
Duration
47 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Spring Boot, Hibernate

Code gaps

assessing knowledge of Hibernate, Java, JPA

Programming task - Level: Medium

Java | Spring Boot, JPA | Repositories - Implement all methods in the ItemRepository class.

Java
JUNIOR
Tested skills
Duration
39 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Core Java, Java, Lambda Expressions, Memory Management

Code gaps

assessing knowledge of Core Java, Java, collections, Memory Management, Lambda Expressions

Programming task - Level: Easy

Java | Core Java | Time Service - Implement solutions based on your knowledge of Java Time API.

Java
MIDDLE
Tested skills
Duration
75 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java and Spring Boot

Code gaps

assessing knowledge of Java and MongoDB

Programming task - Level: Medium

Java | MongoDB, Spring Boot | Flight searcher with MongoDB cache - Implement code that will be able to query multiple airlines for prices according to the client’s request.

The right Java interview questions and online tests to screen Java developers

Recommended roles for our Java Interview Questions

  • Java developer
  • Junior QA developer
  • Frontend developer
  • Full-stack Java developer
  • Junior Java developer
  • Middle Java developer
  • Senior Java developer

How our Java interview questions and online tests work

Java tests use RealLifeTesting™ so you can assess each applicant’s knowledge of Java coding in a controlled environment. DevSkiller Java coding questions provide you with a clear understanding of an applicant’s coding ability and problem-solving skills.

Key features

  • DevSkiller Java coding questions provide you with clear insight into each applicant’s specific skillset
  • Remote testing saves you time and money
  • RealLifeTesting™ methodology offers a greater user experience where candidates can use their own IDE, clone to GIT, run unit tests, and access Stack Overflow/GitHub/Google for research.
  • The latest anti-plagiarism tools ensure reliable results
  • Clear, precise results that non-technical professionals will easily understand
  • Java coding tests available for all levels of experience

Skills covered in our Java interview questions and online tests

  • Springboot
  • Java
  • QA
  • Selenium
  • MongoDB
  • Mavern
  • Explicit Wait
  • Kotlin
  • REST

What to look for in a Java developer

Java is a compiled, object-oriented programming language. It is intended to let application developers “write once, run anywhere,” meaning that compiled Java code can run on all platforms that support Java, without the need for recompilation. However Java is not considered the easiest programming language to use for non-programmers, so you will want to hire the right Java developer for the job.

It is important to understand that the Java world evolves quickly so your ideal candidate will need to have up to date, relevant experience. Your Java developer will need to have an understanding of Java language through collections, “streams” and lambda expressions and concurrency through thread pools. They should have knowledge of frameworks including Spring Boot 2, Hibernate and SQL, JUnit, and Spock among others. As well as the language itself, your Java developer will also need to have knowledge of the tools and libraries of the language, such as Maven and Gradle, Git, and Docker – this will pay dividends in time-saving further down the line. Finally, your Java Developer should have hands-on, practical experience of working on actual coding projects, be it commercial or otherwise.

Build your own custom Java Coding Questions

Do you want to test our Java Coding Questions using your own codebase? No problem. The DevSkiller online task wizard is stacked with awesome features that allow you to customize your test invites. Choose the languages you want to test, define the test scope, and duration all while monitoring your applicants’ process in real-time. Remote testing means you can conveniently test your applicants and find the best talent from all corners of the globe.

Interested but want to know more about our Java online tests?

If you think DevSkiller might be just what your business needs, but you want to be sure, check out the case study below:

Ada Health

Ada Health is a global health company founded by doctors, scientists, and industry pioneers to create new possibilities for personal health. The company previously screened tech skills through an on-site task, followed by a team interview- a procedure that required a great deal of time. For this reason, the biggest objective Ada had was an improved interview experience that would save time.

“DevSkiller helped us to save precious on-site time for applicants that are already likely to be a fit. We’re saving 3 hours per candidate – that was the time we spent with applicants on a technical task before.”

Micha Gerwig– Engineering Manager Ada Health

Frequently asked questions

How are Java online tests evaluated?

With our Java online tests, once the candidate has completed the test, the results are automatically evaluated and presented in a clear and concise way. You don’t have to be technically minded to understand them. Each candidate is evaluated based on the solutions they have provided, with each candidate being assessed based on whether their solution would work, the quality of the code, and any errors in the code. In addition, extra features test for plagiarism from previous tests.

How do candidates take a test?

DevSkiller’s Java online tests are accessible from anywhere, meaning all the recruiter has to do is provide the test, then it is up to the candidate to come up with the right results. Each test can be made accessible for a limited time. Candidates can complete tests using their favorite IDE and then clone the project to GIT. Candidates can also run unit tests to make sure their solutions are effective. Once completed, test results are automatically evaluated and presented to the recruiter in the form of a report.

How long does it take to set up DevSkiller?

DevSkiller provides an extensive library of Java coding tests, meaning you can start testing candidates immediately after setting up your account. The whole process of setting up your Java coding questions can take as little as five minutes.

What do candidates think of DevSkiller tests?

Feedback received from candidates is that they love the structure of DevSkiller Java coding tests. We find candidates like having a chance to prove their software development skills, rather than simply trying to churn out old algorithms that they haven’t touched since they were students. They also like that DevSkiller tests use normal coding practices and conventional tools like unit testing and cloning to GIT from a personal IDE.

If developer candidates are apprehensive about taking the test, their suspicions usually come from experience taking algorithmic tests- tests that don’t monitor the actual skills a developer uses on an everyday basis. With DevSkiller online tests, we find that candidates can immediately tell the difference and can test their Java coding skills in a way that is challenging but also a fair representation of the type of work they will be doing.

What’s the test duration?

Java coding tests are flexible and you can set the duration to suit your own preferences. You have the option to use the default settings, or to cater the test to your own needs. Furthermore, each individual question within a test, can also be set with time-limits.