Checkout the latest source and run mvn spring-boot:run
this would run the server in the console. then you can do the curl on another terminal
curl -X PUT --data-urlencode value='10+2*3' localhost:6666/calculate
you have to change the -d into --data-urlencode since curl interprets + as space
I found a library that can do what you are asking. Check out exp4j. Is this your intention?
Majority of the time I spent here is configuring the Spring Framework, which is expected for Java. I just added 2 classes. CalculatorService CalculatorController