With a small amount of work, you can speed up your application and improve the overall user experience. In this article, you will learn how to use the built-in HTTP response cache mechanism for Spring controller’s results.
Continue reading “HTTP cache with Spring examples”
Writing parameterized tests in JUnit 4 was pretty cumbersome. JUnit 5 introduced several useful improvements to the framework and running the same test with different arguments is much simpler than in the previous version. However, there is one small issue with passing null values in such arguments.
In this post, I’m going to show you how to pass null in @CvsSource and @ValueSource for @ParametrziedTest in JUnit 5.
Continue reading “@ParameterizedTest with null values in @CvsSource”
Do you have multiple parameters annotated with @RequestParam in a request mapping method and feel it isn’t readable?
The annotation looks pretty straightforward when there’s one or two input parameters expected in a request but when the list gets longer you might feel overwhelmed.
You cannot use the @RequestParam annotation inside objects but it doesn’t mean you’re left with no other solution. In this post, I’m going to show you how to replace multiple @RequestParams with an object.
Continue reading “How to bind @RequestParam to object in Spring”
Are you ready?
If so, let’s start with the first element of the puzzle.
Whether you like it or not, software development is a collaborative activity. Integration work has always been demonized and treated as necessary evil. There are several approaches which try to solve the challenge of effective integration. The feature toggle belongs to that group. In this article, you’ll see in practice how feature toggles, also known as feature flags, can be used in your Spring Boot application.
Continue reading “Feature toggle in Spring Boot 2”
It’s been almost two years since Java 8 was officially released and many excellent articles about new enhancements and related best practices have been written through that time. Surprisingly, one of the more controversial topics amongst all the added features is the Optional class. The type is a container, which can be either empty or contain a non-null value. Such construction reminds the user of an Optional object that the situation when there’s nothing inside must be handled appropriately. Although the definition of the type on Javadoc is quite descriptive, when it comes to identifying valid use cases it’s getting more problematic.
Continue reading “Java 8 Optional use cases”
Sending an email from the backend application part is a quite common use case in the world of enterprise applications. Although HTML content isn’t standardized message format, numerous mail clients support at least a subset of the markup language. In this post you will learn how to send an HTML email using Spring Boot standard modules and prepare an HTML content for a message using Thymeleaf template engine.
Continue reading “Sending HTML email with Spring Boot and Thymeleaf”
Although built-in validation support in Spring is largely sufficient for standard use cases, sooner or later you will run into a situation when the sets of validation annotations provided by JSR 303 or Hibernate Validator aren’t enough. In this post you will learn how to create a simple constraint annotation served by a custom validator with access to the Spring context of a Spring Boot application.
Continue reading “Custom validation annotation in Spring”
As software developers, we always look for opportunities to improve our efficiency at work and optimize repeatable activities. One of them is application startup. Even if you cover your production code with unit tests and follow TDD, from time to time checking how the whole application works is inevitable. The more often you run it, the more time is wasted on waiting until the application is ready to operate.
Although the fast restart provided by Spring Boot DevTools is helpful for library class loading, it doesn’t solve the issue with the long startup of your own application code. From this post you will learn how to decrease the total number of coffee breaks in daily work by configuring faster Spring Boot startup in your local development environment.
Continue reading “Faster Spring Boot startup”
The Spring framework with almost no effort can solve for you many common programming problems, but some of its features are less known than others. In this post, we’re going to take a close look at the @Lazy annotation, which belongs to this group. After reading several examples, you should be able to apply the annotation to your daily development tasks.
Continue reading “Spring @Lazy annotation use cases”