Armeria (armeria-spring-boot-actuator-starter)
· Asynchronous HTTP/2 RPC/REST client/server library built on top of Java 8, Netty, Thrift and gRPC (armeria-spring-boot-actuator-starter)
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window armeria-spring-boot-actuator-starter-0.99.7.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.