Best Microframeworks for Java

Classes are seldom extended and interfaces are infrequently implemented in Javalin. This framework is built upon Jetty and consists of only a few thousand lines of code, allowing it to match the performance of Jetty's native implementation. Its compact size makes understanding the source code straightforward. Unlike many other Java and Kotlin web frameworks, which typically provide separate versions for each programming language, Javalin has been designed with interoperability in mind, ensuring that applications can be developed similarly in both Java and Kotlin. Running on Jetty, one of the most widely used and reliable web servers available for the JVM, Javalin allows comprehensive configuration of the Jetty server, including support for SSL, HTTP/3, and all the features Jetty provides. While many lightweight web frameworks in Java and Kotlin lack OpenAPI support, Javalin includes this functionality, making it a more versatile option for developers. Consequently, Javalin stands out as a robust choice for building modern web applications efficiently.

Creating RESTful web services that effectively allow for data exposure in multiple formats while managing the complexities of client-server communication can be quite challenging without the right tools. To ease the process of building RESTful web services and their corresponding clients in Java, the JAX-RS API has been established as a standardized and portable solution. The Jersey framework for RESTful web services 3.x is an open-source, production-ready framework that supports Jakarta RESTful web services 3.0. Beyond merely serving as the JAX-RS reference implementation, Jersey offers its own API, enriching the JAX-RS toolkit with additional capabilities. It also ensures the JAX-RS API is consistently updated, delivering regular releases of high-quality reference implementations that integrate seamlessly with GlassFish. Furthermore, Jersey provides APIs that facilitate extensions, fostering a vibrant community of users and developers. As a result, developers find it significantly easier to create robust RESTful web services using Java and the Java Virtual Machine, paving the way for more innovative applications.