added WrongServiceTypeException

backend/src/main/java/com/vaessl/app/connection/ConnectionService.java

@@ -8,6 +8,7 @@ import org.springframework.stereotype.Service;
 
 import com.vaessl.app.dto.ConnectionRequest;
 import com.vaessl.app.dto.ConnectionResponse;
+import com.vaessl.app.exception.WrongServiceTypeException;
 
 @Service
 public class ConnectionService {
@@ -26,6 +27,10 @@ public class ConnectionService {
 
         ConnectionProvider provider = providerRegistry.get(request.serviceType());
 
+        if (provider == null) {
+            throw new WrongServiceTypeException();
+        }
+
         provider.checkCredentials(request);
 
         ConnectionResponse response = provider.authenticate(request);

backend/src/main/java/com/vaessl/app/exception/ErrorMessage.java

@@ -8,7 +8,7 @@ public enum ErrorMessage {
     BAD_REQUEST_EMPTY_FIELDS(HttpStatus.BAD_REQUEST, "Fields must not be empty."), UNAUTHORIZED_WRONG_LOGIN(
             HttpStatus.UNAUTHORIZED, "Invalid username or password."), SERVICE_UNAVAILABLE_UNREACHABLE_URL(
                     HttpStatus.SERVICE_UNAVAILABLE, "The target URL is unreachable."), SERVER_ERROR_GENERAL(
-                            "The external app returned a server error: "), WRONG_SERVICE_TYPE(HttpStatus.BAD_REQUEST,
+                            "The external app returned a server error: "), WRONG_SERVICE_TYPE(HttpStatus.NOT_FOUND,
                                     "No such service type.");
 
     private final HttpStatus status;

backend/src/main/java/com/vaessl/app/exception/GlobalExceptionHandler.java

@@ -48,6 +48,11 @@ public class GlobalExceptionHandler {
                         SERVER_ERROR_GENERAL.getMessage() + e.getStatusText());
     }
 
+    @ExceptionHandler(WrongServiceTypeException.class)
+    public ProblemDetail handleWrongServiceType(WrongServiceTypeException e) {
+        return ProblemDetail.forStatusAndDetail(WRONG_SERVICE_TYPE.getStatus(), WRONG_SERVICE_TYPE.getMessage());
+    }
+
     @ExceptionHandler(EmptyCredentialsException.class)
     public ProblemDetail handleEmptyCredentials(EmptyCredentialsException e) {
         return ProblemDetail.forStatusAndDetail(BAD_REQUEST_EMPTY_FIELDS.getStatus(),

backend/src/main/java/com/vaessl/app/exception/WrongServiceTypeException.java

@@ -0,0 +1,4 @@
+package com.vaessl.app.exception;
+
+public class WrongServiceTypeException extends RuntimeException {
+}