Blog Archives
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01: JUnit with Mockito step by step

Step 1: Create a simple maven project say “code-quality”

Step 2: Import into eclipse.

#1. Validator code & unit testing

Step 3: Validator interface & implementation

Step 4: Write a unit test to test the “”.

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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”, … Read...

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. …...

02: Unit testing with JUnit, Mockito & Spring

Step 1: Create a simple Maven project from a command-line. Just press enter for all the prompts.

Step 2: Import the above “simple-mocking-test” in the file system into eclipse. File –> Import –> “Existing Maven Projects” and then select the “simple-mocking-test”

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03: Mockito to fully mock the DAO layer

This extends Part 1: Unit testing with JUnit, Mockito & Spring by mocking the DAO layer with the Mockito framework. Step 1: Service and DAO layer interfaces and implementations Service Layer DAO Layer This layer will be mocked by Mockito in the next step. … Read more ›...

04: Mockito partially mocking with @Spy

This extends Part 2: Mockito to fully mock the DAO layer by modifying the service layer to demonstrate partial mocking with “Mockito.spy”. In the “SimpleServiceImpl” we are interested in only testing the method “processUser(int id)” and want to mock the method “getUserById(int id)” by always returning “Sam”. So, … Read...

05: Mockito & PowerMock partially mocking private methods with @Spy

This extends Part 3: Mockito partially mocking with @Spy by making the method “processUser(int id)” as a private method. Mockito framework cannot mock “private” methods, hence the “PowerMock” framework is added to the pom.xml file Step 1: Add “PowerMock” … Read more ›...

06: Mockito & PowerMock for mocking static methods

This extends Part 4: Mockito & PowerMock for partially mocking private methods to mock “static” methods.

How to use both Spring JUnit and PowerMock runners?

By using the “@PowerMockRunnerDelegate” from the “powermock-module-junit4” jar.

So, need to use compatible “Mockito” and “PowerMock”.

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30+ Java Code Review Checklist Items

This Java code review checklist is not only useful during code reviews, but also to answer an important Java job interview question,

Q. How would you go about evaluating code quality of others’ work?

You also learn a lot from peer code reviews. What has been written well?

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5 Java unit testing interview Questions and Answers

Q1 Why use mock objects in unit testing? A1 Unit testing is widely accepted as a “best practice” for software development. When you write an object, you must also provide an automated test class containing methods by calling its various public methods with various parameters and making sure that the...

8+ JMeter performance testing interview Q&As

Performance testing is an important process of any software development. You can bring this up yourself to many open-ended questions like — Tell me about yourself? What are some of your recent accomplishments that you are proud of? Setting up a performance/load test script is always the first step in...

Ensuring code quality in Java Q&As

Q1. How do you ensure code quality in your application? A1. Code quality means writing readable, maintainable and robust code, that conforms as much as possible to the style-guideline that is used, and that has as little as possible defects. … Read more ›...

Integration Unit testing Spring Transaction Management

This is an integration testing that tests Spring transaction through service, and DAO layers all the way up to the embedded database like HSQLDB or H2. After commit or rollback, the number of records in the table are verified. The service layer defines the transactional boundaries with the “@Transactional” annotation....

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800+ Java Q&As & tutorials