20200418 MicroService Java Spark HTTP GET

For testing the Java Spark framework I have implemented a small example with a HTTP GET handler.

FYI : Yes, I know the HTTP Protocol and that GET requests shall not store anything or change the state of the service.

In this example I store all HTTP header parameters in a member map of my microservice to see if its state is re-used as expected for continuous accesses.

This is my Java code :

    package de.wartbar.sparkserver;

    import com.google.gson.Gson;
    import spark.Request;
    import java.util.HashMap;
    import static spark.Spark.*;

    public class Main {

      private static HashMap<String, String> map = new HashMap<>();

      public static String addParameter(Request req) {

        synchronized (map) {
          for (String key : req.queryParams()) {
            System.out.println(key + " : " + req.queryParams(key));
            map.put(key, req.queryParams(key));
          }
        }

        Gson gson = new Gson();
        String json = gson.toJson(map);

        return json;
      }

      public static void main(String[] args) {

        get("/hello", (req, res) -> addParameter(req));

      }
    }