quarkusio/quarkus · error · ConstraintViolationException

(dynamic: return value constraint violations summary for the

Error message

(dynamic: return value constraint violations summary for the invoked method)

What it means

This ConstraintViolationException is thrown by the method-validation interceptor AFTER the method body has already executed and returned, when ExecutableValidator.validateReturnValue finds the returned value violates constraints declared on the method (e.g. @NotNull on the return type or on elements of the returned collection). The method's side effects already happened even though its result is rejected.

Source

Thrown at extensions/hibernate-validator/runtime/src/main/java/io/quarkus/hibernate/validator/runtime/interceptor/AbstractMethodValidationInterceptor.java:78

     *         return value validation.
     */
    protected Object validateMethodInvocation(InvocationContext ctx) throws Exception {

        ExecutableValidator executableValidator = validatorInstance.get().forExecutables();
        Set<ConstraintViolation<Object>> violations = executableValidator.validateParameters(ctx.getTarget(),
                ctx.getMethod(), ctx.getParameters());

        if (!violations.isEmpty()) {
            throw new ConstraintViolationException(getMessage(ctx.getMethod(), ctx.getParameters(), violations),
                    violations);
        }

        Object result = ctx.proceed();

        violations = executableValidator.validateReturnValue(ctx.getTarget(), ctx.getMethod(), result);

        if (!violations.isEmpty()) {
            throw new ConstraintViolationException(getMessage(ctx.getMethod(), ctx.getParameters(), violations),
                    violations);
        }

        return result;
    }

    /**
     * Validates the Bean Validation constraints specified at the parameters and/or
     * return value of the intercepted constructor.
     *
     * @param ctx The context of the intercepted constructor invocation.
     *
     * @throws Exception Any exception caused by the intercepted constructor
     *         invocation. A {@link ConstraintViolationException} in case
     *         at least one constraint violation occurred either during
     *         parameter or return value validation.
     */
    protected void validateConstructorInvocation(InvocationContext ctx) throws Exception {

View on GitHub (pinned to e1c734241f)

Solutions

1. Fix the bean implementation so the returned value satisfies the declared constraints (return Optional instead of null, filter invalid elements).
2. Relax or remove the return-value constraint annotation if returning null/invalid values is legitimate.
3. Check the violation set for the exact property path; if cascading (@Valid) is involved, fix the nested object's fields.
4. For query-style methods, use Optional<T> return types instead of @NotNull + null.

Example fix

// before
@NotNull
public User find(String id) { return repo.find(id); } // may return null

// after
public Optional<User> find(String id) { return Optional.ofNullable(repo.find(id)); }

Set<ConstraintViolation<Object>> v = validator.forExecutables().validateReturnValue(target, method, result);
if (!v.isEmpty()) { /* result violates declared constraints */ }

boolean isValidResult = result != null; // for a @NotNull-returning method call site

try { User u = service.find(id); } catch (ConstraintViolationException e) { // side effects may have occurred; inspect e.getConstraintViolations() }

When it happens

Trigger: A validated bean method returns a value violating its return-value constraints (e.g. returns null where @NotNull return type is declared, or a list containing null elements under @NotNull List<@NotNull T>); thrown at AbstractMethodValidationInterceptor.java:77-80 after ctx.proceed().

Common situations: A repository method annotated with @NotNull return returns null when a row is missing; a service returning an optional result as null; adding return-type constraints to legacy methods whose implementations sometimes return null.

Related errors

• (dynamic: parameter constraint violations summary for the in
• (dynamic: constructor parameter constraint violations summar
• (dynamic: constructor return value constraint violations sum
• Fruit Name was not set on request.

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/e1d44c3645b28350. Report an issue: GitHub.