This is not an idempotent function ... This step-by-step Spring Boot RESTful web services example in Java has very few prerequisites, but it does assume that you have the SpringSource Tool Suite (STS) ...

not Tomcat. Tomcat doesn't provide built in JAX-RS support. To test the application, first right-click on the restful Java project, and choose Run As > Run on server. This will deploy the web project ...