quarkusio/quarkus · error · UnableToParseMethodException

fieldNotResolvableMessage + offendingMethodMessage

Error message

fieldNotResolvableMessage + offendingMethodMessage

What it means

While resolving a possibly underscore-separated (nested) field path in a derived query method, the parser consumed a segment but ran off the end of the expression without finding a next segment, meaning the path was truncated. It throws UnableToParseMethodException with the 'Entity ... does not contain a field named: ...' prefix.

Source

Thrown at extensions/spring-data-jpa/deployment/src/main/java/io/quarkus/spring/data/deployment/MethodNameParser.java:517

        FieldInfo fieldInfo = null;

        MutableReference<List<ClassInfo>> parentSuperClassInfos = new MutableReference<>();
        int fieldStartIndex = 0;
        ClassInfo parentFieldInfo = null;
        while (fieldStartIndex < fieldPathExpression.length()) {
            // The underscore character is treated as reserved character to manually define traversal points.
            // This means that path expression may have multiple levels separated by the '_' character. For example: person_address_city.
            if (fieldPathExpression.charAt(fieldStartIndex) == '_') {
                // See issue #34395
                // For resolving correctly nested fields added using '_' we need to get the previous fieldInfo which will be the class containing the field starting by '_' in this loop.
                DotName parentFieldInfoName;
                if (fieldInfo != null && fieldInfo.type().kind() == Type.Kind.PARAMETERIZED_TYPE) {
                    parentFieldInfoName = fieldInfo.type().asParameterizedType().arguments().stream().findFirst().get().name();
                    parentFieldInfo = indexView.getClassByName(parentFieldInfoName);
                }
                fieldStartIndex++;
                if (fieldStartIndex >= fieldPathExpression.length()) {
                    throw new UnableToParseMethodException(fieldNotResolvableMessage + offendingMethodMessage);
                }
            }
            int firstSeparator = fieldPathExpression.indexOf('_', fieldStartIndex);
            int fieldEndIndex = firstSeparator == -1 ? fieldPathExpression.length() : firstSeparator;
            while (fieldEndIndex >= fieldStartIndex) {
                String fieldName = fieldPathExpression.substring(fieldStartIndex, fieldEndIndex);
                String simpleFieldName = lowerFirstLetter(fieldName);
                fieldInfo = getFieldInfo(simpleFieldName, parentFieldInfo == null ? parentClassInfo : parentFieldInfo,
                        parentSuperClassInfos);
                if (fieldInfo != null) {
                    break;
                }
                fieldEndIndex = previousPotentialFieldEnd(fieldPathExpression, fieldStartIndex, fieldEndIndex);
            }
            if (fieldInfo == null) {
                String detail = "";
                if (fieldStartIndex > 0) {
                    String notMatched = lowerFirstLetter(fieldPathExpression.substring(fieldStartIndex));

View on GitHub (pinned to e1c734241f)

Solutions

Complete the field path after the underscore: findByAddress_City(...)
Remove the trailing underscore if the field is not nested: findByAddress(...)
Use @Query with explicit JPQL for complex nested paths

Example fix

// before
List<User> findByAddress_();
// after
List<User> findByAddress_City(String city);

Defensive patterns

Strategy: validation

Validate before calling

// Check for dangling separators in method names:
// assertFalse(methodName.contains("__") || methodName.endsWith("_"), methodName);

Try / catch

try {
    parser.parse(methodName);
} catch (UnableToParseMethodException e) {
    // complete or remove the trailing underscore path
    throw new IllegalStateException("Truncated nested path: " + e.getMessage());
}

Prevention

Never end a field path with an underscore
Use underscore-separated full paths: findByAddress_City(...)
Review auto-generated or scripted repository method names for truncated paths

When it happens

Trigger: A method name field path ends with an underscore or trailing separator, e.g. findByAddress_ (nothing after '_'), or the path after the last '_' is empty — fieldStartIndex reaches fieldPathExpression.length().

Common situations: Half-deleted nested path during refactoring; auto-generated method names with dangling separators; typos where the final segment was omitted.

Related errors

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/92546b5189cc6508. Report an issue: GitHub.