Reasons for Sustained Popularity
Flexibility and integration with other frameworks
Spring has a very flexible architecture. Spring modules are not dependent on one another and offer a developer the freedom to pick and choose according to the requirements of the application. Spring projects are designed with very specific purposes in mind.
Spring offers integration with a large number of frameworks. For example, even though Spring offers its own MVC framework, SpringMVC, it also offers integration with other MVC frameworks. Using Spring does not decrease the developer’s options.
Removes plumbing code
Plumbing code not only makes programming longer but also reduces the readability of code. For example, in JDBC programming, a lot of code is required for simple functionality. Connection establishment and exception handling span many lines of code.
Spring removes plumbing code and lets the programmer focus on the application logic. The amount of code written in Spring is negligible. No exception handling code is required because Spring makes all its exceptions unchecked.
Promotes testable code
Spring framework enables writing testable code. It offers good integration with JUnit and Mockito frameworks, which lets us write unit tests quickly and easily. The core feature of Spring is dependency injection and if it is used properly, writing unit tests for the code becomes very easy.
Staying up to date
Spring is able to stay current and adapt to changes in development. For example, microservices and cloud services have evolved in the last decade. Spring has come up with projects to keep up with the trend, like Spring Boot, which helps with designing microservices.