Although the concept of microservices has been an important topic for some years, there are still not many stable frameworks that support all the features needed to run full microservices environments. Since the beginning of my adventure with microservices, I have been trying to keep up with the latest frameworks and find out the features developed towards the needs of microservices. There are some other interesting solutions, such as Vert.x or Apache Camel, but none of them is a match for Spring Framework.
Spring Cloud implements all proven patterns that are used in microservice-based architecture, such as service registries, the configuration server, circuit breakers, cloud buses, OAuth2 patterns, and API gateways. It has a strong community, therefore new features are released at a high frequency. It is based on Spring's open programming model used by millions of Java developers worldwide. It is also well-documented. You won't have any problems in finding many available examples of Spring Framework usage online.
