added ErrorMessages enum

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

@@ -0,0 +1,29 @@
+package com.vaessl.app.exception;
+
+import org.springframework.http.HttpStatus;
+
+import lombok.Getter;
+
+@Getter
+public enum ErrorMessages {
+
+    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: ");
+
+    private final HttpStatus status;
+    private final String message;
+
+    ErrorMessages(HttpStatus status, String message) {
+        this.status = status;
+        this.message = message;
+    }
+    
+    ErrorMessages(String message) {
+        this.status = null;
+        this.message = message;
+    }
+
+
+} 

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

@@ -1,6 +1,5 @@
 package com.vaessl.app.exception;
 
-import org.springframework.http.HttpStatus;
 import org.springframework.http.ProblemDetail;
 import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.ExceptionHandler;
@@ -9,24 +8,29 @@ import org.springframework.web.client.HttpClientErrorException;
 import org.springframework.web.client.HttpServerErrorException;
 import org.springframework.web.client.ResourceAccessException;
 
+import static com.vaessl.app.exception.ErrorMessages.*;
+
 @RestControllerAdvice
 public class GlobalExceptionHandler {
 
     @ExceptionHandler(MethodArgumentNotValidException.class)
     public ProblemDetail handleEmptyCredentialInput(MethodArgumentNotValidException e) {
-        return ProblemDetail.forStatusAndDetail(HttpStatus.BAD_REQUEST, "Fields must not be empty.");
+        return ProblemDetail.forStatusAndDetail(BAD_REQUEST_EMPTY_FIELDS.getStatus(),
+                BAD_REQUEST_EMPTY_FIELDS.getMessage());
     }
 
     @ExceptionHandler(HttpClientErrorException.Unauthorized.class)
     public ProblemDetail handleUnauthorizedAccess(HttpClientErrorException e) {
 
-        return ProblemDetail.forStatusAndDetail(HttpStatus.UNAUTHORIZED, "Invalid username or password.");
+        return ProblemDetail.forStatusAndDetail(UNAUTHORIZED_WRONG_LOGIN.getStatus(),
+                UNAUTHORIZED_WRONG_LOGIN.getMessage());
     }
 
     @ExceptionHandler(ResourceAccessException.class)
     public ProblemDetail handleNoConnection(ResourceAccessException e) {
 
-        return ProblemDetail.forStatusAndDetail(HttpStatus.SERVICE_UNAVAILABLE, "The target URL is unreachable.");
+        return ProblemDetail.forStatusAndDetail(SERVICE_UNAVAILABLE_UNREACHABLE_URL.getStatus(),
+                SERVICE_UNAVAILABLE_UNREACHABLE_URL.getMessage());
     }
 
     @ExceptionHandler(HttpServerErrorException.class)
@@ -34,6 +38,6 @@ public class GlobalExceptionHandler {
 
         return ProblemDetail
                 .forStatusAndDetail(e.getStatusCode(),
-                        "The external app returned a server error: " + e.getStatusText());
+                        SERVER_ERROR_GENERAL.getMessage() + e.getStatusText());
     }
 }