alibaba/spring-cloud-alibaba · error · IllegalArgumentException

{type} method attribute exists but {type} class attribute is

Error message

{type} method attribute exists but {type} class attribute is not exists in bean[{beanName}]

What it means

The mirror of error 103: a method-name attribute is supplied for a RestTemplate Sentinel handler (block/fallback/urlCleaner) but the corresponding class attribute is empty. Because the handler is resolved as a static method on a named class, a method without a class cannot be located, so Sentinel refuses the configuration at bean post-processing time.

Source

Thrown at spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-sentinel/src/main/java/com/alibaba/cloud/sentinel/custom/SentinelBeanPostProcessor.java:124

	}

	private void checkBlock4RestTemplate(Class<?> blockClass, String blockMethod,
			String beanName, String type) {
		if (blockClass == void.class && !StringUtils.hasLength(blockMethod)) {
			return;
		}
		if (blockClass != void.class && !StringUtils.hasLength(blockMethod)) {
			log.error(
					"{} class attribute exists but {} method attribute is not exists in bean[{}]",
					type, type, beanName);
			throw new IllegalArgumentException(type + " class attribute exists but "
					+ type + " method attribute is not exists in bean[" + beanName + "]");
		}
		else if (blockClass == void.class && StringUtils.hasLength(blockMethod)) {
			log.error(
					"{} method attribute exists but {} class attribute is not exists in bean[{}]",
					type, type, beanName);
			throw new IllegalArgumentException(type + " method attribute exists but "
					+ type + " class attribute is not exists in bean[" + beanName + "]");
		}
		Class[] args;
		if (type.equals(SentinelConstants.URLCLEANER_TYPE)) {
			args = new Class[] {String.class};
		}
		else {
			args = new Class[] {HttpRequest.class, byte[].class,
					ClientHttpRequestExecution.class, BlockException.class};
		}
		String argsStr = Arrays.toString(
				Arrays.stream(args).map(clazz -> clazz.getSimpleName()).toArray());
		Method foundMethod = ClassUtils.getStaticMethod(blockClass, blockMethod, args);
		if (foundMethod == null) {
			log.error(
					"{} static method can not be found in bean[{}]. The right method signature is {}#{}{}, please check your class name, method name and arguments",
					type, beanName, blockClass.getName(), blockMethod, argsStr);
			throw new IllegalArgumentException(type

View on GitHub (pinned to 115d590110)

Solutions

1. Add the matching class attribute, e.g. spring.cloud.sentinel.resttemplate.block-class=com.example.MyBlock.
2. If you did not mean to configure this handler, remove the method attribute so both are unset.
3. Verify the class is on the classpath and visible to the bean post-processor.

Example fix

// before
@SentinelRestTemplate(blockMethod = "handleBlock")
// after
@SentinelRestTemplate(blockClass = MyBlock.class, blockMethod = "handleBlock")

void validateHandler(Class<?> clazz, String method) {
  boolean hasClass = clazz != null && clazz != void.class;
  boolean hasMethod = method != null && !method.isBlank();
  if (hasClass != hasMethod) throw new IllegalStateException("class and method attributes must both be set or both be empty");
}

When it happens

Trigger: Configuring spring.cloud.sentinel.resttemplate.block-method=handleBlock with no block-class, or @SentinelRestTemplate(blockMethod = "handleBlock") and no blockClass.

Common situations: Removing or commenting out the class line while keeping the method line. Copying a partial config snippet from documentation.

Related errors

• {type} class attribute exists but {type} method attribute is
• {type} static method can not be found in bean[{beanName}]. T
• {type} method return value in bean[{beanName}] is not {stand
• [Sentinel Starter] DataSource {dataSourceName}dataType is cu
• [Sentinel Starter] DataSource {dataSourceName} dataType: {pr

AI-assisted analysis of alibaba/spring-cloud-alibaba@115d590110 (2026-08-14). Data as JSON: /api/errors/cf0e1f91b2d928b8. Report an issue: GitHub.