spring-projects/spring-framework · error · UnsupportedOperationException

Spring AOP cannot handle constructor advice

Error message

Spring AOP cannot handle constructor advice

What it means

Thrown as an UnsupportedOperationException from AspectJAnnotationParameterNameDiscoverer.getParameterNames(Constructor). Spring AOP only supports method-level advice (@Before, @After, @Around, etc.); AspectJ also allows constructor execution/initialization advice, but Spring's proxy-based AOP cannot intercept constructors. This is triggered if the parameter-name discovery path is exercised for a constructor, which does not occur during normal Spring AOP processing.

Solutions

1. Do not attempt constructor-level advice through Spring AOP; use method-level advice instead.
2. Avoid calling getParameterNames(Constructor) on the AspectJ annotation parameter discoverer; use a different discoverer for constructors.
3. If constructor interception is required, use AspectJ compile-time or load-time weaving.

// Spring AOP never invokes constructor parameter discovery through this path in normal use.
// Defense: do not call AspectJAnnotationParameterNameDiscoverer.getParameterNames(Constructor).
// Use a different ParameterNameDiscoverer (e.g., DefaultParameterNameDiscoverer) for constructors.

// Not applicable in user code; if extending the framework, guard before calling:
ParameterNameDiscoverer discoverer = ...;
if (executable instanceof Method mth) {
    return discoverer.getParameterNames(mth); // safe for AspectJ discoverer
} else {
    return otherDiscoverer.getParameterNames((Constructor<?>) executable);
}

When it happens

Trigger: A custom ParameterNameDiscoverer wiring that calls getParameterNames(Constructor) on the AspectJAnnotationParameterNameDiscoverer; framework/test code invoking parameter discovery on a constructor of an advice type; programmatic misuse of the internal discoverer.

Common situations: Tooling or extensions that reuse Spring's ParameterNameDiscoverer infrastructure on constructors; misconfiguration where a generic discoverer chain is applied to constructors; user attempting to define constructor advice via Spring AOP (not supported).

Related errors

• Advice method [ ] requires arguments to be bound by name…
• Advice must be declared inside an aspect type: Offending…
• An advice method can never be a constructor
• is not a valid AspectJ annotation
• 'argumentNames' property of AbstractAspectJAdvice contains…

AI-assisted analysis of spring-projects/spring-framework@69bf83ad71 (2026-08-09). Data as JSON: /api/errors/8bbf33fbc91329be. Report an issue: GitHub.

Appendix: source

Thrown at spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/AbstractAspectJAdvisorFactory.java:267

				return null;
			}
			StringTokenizer nameTokens = new StringTokenizer(annotation.getArgumentNames(), ",");
			int numTokens = nameTokens.countTokens();
			if (numTokens > 0) {
				String[] names = new String[numTokens];
				for (int i = 0; i < names.length; i++) {
					names[i] = nameTokens.nextToken();
				}
				return names;
			}
			else {
				return null;
			}
		}

		@Override
		public @Nullable String @Nullable [] getParameterNames(Constructor<?> ctor) {
			throw new UnsupportedOperationException("Spring AOP cannot handle constructor advice");
		}
	}

}

View on GitHub (pinned to 69bf83ad71)