--- /dev/null
+package de.juplo.kafka;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+
+@RestController
+@RequiredArgsConstructor
+public class ApplicationController
+{
+ private final AdderBusinessLogic adder;
+
+
+ @GetMapping("state/{user}")
+ public ResponseEntity<Long> state(@PathVariable String user)
+ {
+ return adder
+ .getSum(user)
+ .map(sum -> ResponseEntity.ok(sum))
+ .orElseGet(() -> ResponseEntity.notFound().build());
+ }
+
+
+ @ExceptionHandler
+ @ResponseStatus(HttpStatus.BAD_REQUEST)
+ public ErrorResponse illegalStateException(IllegalStateException e)
+ {
+ return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
+ }
+}