The Spring framework is widespread because it provides a wide range of features that make it well-suited for developing enterprise Java applications. Some of the main reasons it is famous include:
Dependency injection (DI): Spring’s DI feature makes it easy to manage and configure dependencies between different objects in an application, which can make code more maintainable and testable.
Modularity: The Spring framework is modular, so developers can use only the specific features they need for their project rather than an entire monolithic framework.
Abstraction from different technologies: Spring provides several abstractions that can help insulate the application from the specific details of underlying technologies like JDBC, JMS, and transactions.
Testing support: Spring provides features that make writing tests for an application more accessible, such as easy mock dependencies and integration testing support.