Mocking is an essential part of unit testing, and the Mockito library makes it easy to write clean and intuitive unit tests for your Java code.
Get started with mocking and improve your application tests using our Mockito guide:
Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.
Get started with understanding multi-threaded applications with our Java Concurrency guide:
Spring 5 added support for reactive programming with the Spring WebFlux module, which has been improved upon ever since. Get started with the Reactor project basics and reactive programming in Spring Boot:
Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.
But these can also be overused and fall into some common pitfalls.
To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:
Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:
Yes, Spring Security can be complex, from the more advanced functionality within the Core to the deep OAuth support in the framework.
I built the security material as two full courses - Core and OAuth, to get practical with these more complex scenarios. We explore when and how to use each feature and code through it on the backing project.
You can explore the course here:
Spring Data JPA is a great way to handle the complexity of JPA with the powerful simplicity of Spring Boot.
Get started with Spring Data JPA through the guided reference course:
Refactor Java code safely — and automatically — with OpenRewrite.
Refactoring big codebases by hand is slow, risky, and easy to put off. That’s where OpenRewrite comes in. The open-source framework for large-scale, automated code transformations helps teams modernize safely and consistently.
Each month, the creators and maintainers of OpenRewrite at Moderne run live, hands-on training sessions — one for newcomers and one for experienced users. You’ll see how recipes work, how to apply them across projects, and how to modernize code with confidence.
Join the next session, bring your questions, and learn how to automate the kind of work that usually eats your sprint time.
Regression testing is an important step in the release process, to ensure that new code doesn't break the existing functionality. As the codebase evolves, we want to run these tests frequently to help catch any issues early on.
The best way to ensure these tests run frequently on an automated basis is, of course, to include them in the CI/CD pipeline. This way, the regression tests will execute automatically whenever we commit code to the repository.
In this tutorial, we'll see how to create regression tests using Selenium, and then include them in our pipeline using GitHub Actions:, to be run on the LambdaTest cloud grid:
1. Overview
In this tutorial, we’ll explore different ways to check if two integers have the same sign in Java. This is a common requirement in mathematical computations, validations, and optimization checks.
We’ll start with simple conditional logic and then move to more compact or efficient approaches.
2. Using Simple Conditional Checks
The most straightforward approach is to check whether both numbers are non-negative or both are negative:
int a = 5;
int b = -3;
boolean sameSign = (a >= 0 && b >= 0) || (a < 0 && b < 0);
Here, the condition explicitly verifies that either both values are non-negative or both are negative. While it might be a bit too explicit, simplistic, and considered to be non-elegant, this approach has a significant advantage: it works and it’s readable. However, we can wrap this logic inside a function to add clarity and improve reusability.
3. Using Multiplication
We can also rely on the product of two integers:
boolean sameSign = (a * b) > 0;
If the product is positive, then both numbers have the same sign. This approach isn’t very expressive and requires some time to understand what’s going on. Additionally, it has a problem with overflowing and multiplying by zero. While it’s a very inventive way to solve the problem, it’s too cryptic, prone to errors, and might affect the performance of an application.
4. Using Bitwise Operators
Another option is to compare the sign bits of the numbers, which is similar to the previous one, but doesn’t have the disadvantage of multiplication. In two’s complement representation, the sign of an integer is stored in the most significant bit:
boolean sameSign = (a ^ b) >= 0;
In this case, we’re applying an XOR operation to the bit that’s responsible for the sign: if they’re different, the bit would be set to one, and the final value would be negative. However, since bitwise operators are pretty rare, especially XOR, if we decide to go with this approach, the logic (even a single line) should be wrapped into a method.
5. Using Java’s Math.signum()
Java provides the Math.signum() method, which returns -1.0, 0.0, or 1.0 depending on the sign. This might be pretty useful in calculations:
boolean sameSign = Math.signum(a) == Math.signum(b);
This approach is very clear and avoids manual checks, but note that it operates on double values internally. Thus, to avoid additional conversions, it’s better to implement our own checks; fortunately, the logic is straightforward.
6. Handling Zeros
Depending on the context, we can consider zero to be either neutral or having the same sign as non-negative numbers. For example, zero and five may or may not be treated as the same sign. A reasonable option is to treat zero as non-negative, since it aligns with Math.signum(0) returning 0.0 and makes comparisons with positive numbers more intuitive. However, in strict mathematical contexts, you might prefer to handle zero separately to avoid ambiguity.
7. Conclusion
There are several ways to compare the signs of numbers. However, the best one is the one that would be the most readable and understandable in our codebase. Often, the simplest and dullest approach is what we need. If the checks become verbose, we can use encapsulation and move the logic to a separate method, making it even more readable and understandable.
