Clean up unused validateFieldName() and use existing methods for Text…

…EmbeddingProcessorIT (#1074)

Signed-off-by: Yizhe Liu <[email protected]>

src/main/java/org/opensearch/neuralsearch/util/ProcessorDocumentUtils.java

@@ -296,30 +296,6 @@ private static void unflattenSingleItem(String key, Object value, Map<String, Ob
         }
     }
 
-    /**
-     * Validate if field name is in correct format, which is either "a", or "a.b.c".
-     * If field name is like "..a..b", "a..b", "a.b..", it should be invalid.
-     * This is done via checking if a string contains empty segments when split by dots.
-     *
-     * @param input the string to check
-     * @throws IllegalArgumentException if the input is null or has invalid dot usage
-     */
-    private static void validateFieldName(String input) {
-        if (StringUtils.isBlank(input)) {
-            throw new IllegalArgumentException("Field name cannot be null or empty");
-        }
-
-        // Use split with -1 limit to preserve trailing empty strings
-        String[] segments = input.split("\\.", -1);
-
-        // Check if any segment is empty
-        for (String segment : segments) {
-            if (StringUtils.isBlank(segment)) {
-                throw new IllegalArgumentException(String.format(Locale.ROOT, "Field name '%s' contains invalid dot usage", input));
-            }
-        }
-    }
-
     // Helper classes to maintain state during iteration
     private static class ProcessJsonObjectItem {
         String key;