spring-projects/spring-framework · error · IllegalArgumentException

Property 'targetBeanName' is required

Error message

Property 'targetBeanName' is required

What it means

MethodLocatingFactoryBean is a FactoryBean that resolves a java.lang.reflect.Method from a target bean during BeanFactory initialization. The 'targetBeanName' property names which bean to introspect; without it there is no class to look the method up on. The exception is thrown from setBeanFactory() (the BeanFactoryAware callback, line 64) so the failure surfaces at application-context startup.

Solutions

1. Add <property name="targetBeanName" value="myServiceBean"/> (XML) or call factoryBean.setTargetBeanName("myServiceBean") so the bean has a non-blank name
2. Confirm the bean name you supply matches an actual bean id/name in the same ApplicationContext
3. Run a quick grep on the config for MethodLocatingFactoryBean and verify every occurrence sets both targetBeanName and methodName

Example fix

// before
<bean id="myMethod" class="org.springframework.aop.config.MethodLocatingFactoryBean">
  <property name="methodName" value="doWork"/>
</bean>

// after
<bean id="myMethod" class="org.springframework.aop.config.MethodLocatingFactoryBean">
  <property name="targetBeanName" value="myService"/>
  <property name="methodName" value="doWork"/>
</bean>

// Before relying on the factory bean, ensure the property is set:
if (!StringUtils.hasText(factoryBean.getTargetBeanName())) {
  throw new IllegalStateException("targetBeanName not set on MethodLocatingFactoryBean");
}

private static boolean hasTargetBeanName(MethodLocatingFactoryBean fb) {
  return fb != null && StringUtils.hasText(fb.getTargetBeanName());
}

When it happens

Trigger: Defining a MethodLocatingFactoryBean bean (XML, Java @Bean, or GenericBeanDefinition) and never calling setTargetBeanName(...) before the context initializes it. The check is !StringUtils.hasText(this.targetBeanName), so null, empty, or whitespace-only all trip it.

Common situations: XML <bean class="...MethodLocatingFactoryBean"> missing the <property name="targetBeanName" .../> element; a typo in the property name; a refactored config that accidentally dropped the setter call; copy-pasting a bean definition without the required properties.

Related errors

• Property 'methodName' is required
• Can't determine type of bean with name
• Property 'target' is required
• Unable to locate method
• Both 'constructorArgs' and 'constructorArgTypes' need to be…

AI-assisted analysis of spring-projects/spring-framework@69bf83ad71 (2026-08-09). Data as JSON: /api/errors/1c25e48f1486e173. Report an issue: GitHub.

Appendix: source

Thrown at spring-aop/src/main/java/org/springframework/aop/config/MethodLocatingFactoryBean.java:65

	 * @param targetBeanName the name of the bean to locate the {@link Method} on
	 */
	public void setTargetBeanName(String targetBeanName) {
		this.targetBeanName = targetBeanName;
	}

	/**
	 * Set the name of the {@link Method} to locate.
	 * <p>This property is required.
	 * @param methodName the name of the {@link Method} to locate
	 */
	public void setMethodName(String methodName) {
		this.methodName = methodName;
	}

	@Override
	public void setBeanFactory(BeanFactory beanFactory) {
		if (!StringUtils.hasText(this.targetBeanName)) {
			throw new IllegalArgumentException("Property 'targetBeanName' is required");
		}
		if (!StringUtils.hasText(this.methodName)) {
			throw new IllegalArgumentException("Property 'methodName' is required");
		}

		Class<?> beanClass = beanFactory.getType(this.targetBeanName);
		if (beanClass == null) {
			throw new IllegalArgumentException("Can't determine type of bean with name '" + this.targetBeanName + "'");
		}
		this.method = BeanUtils.resolveSignature(this.methodName, beanClass);

		if (this.method == null) {
			throw new IllegalArgumentException("Unable to locate method [" + this.methodName +
					"] on bean [" + this.targetBeanName + "]");
		}
	}

View on GitHub (pinned to 69bf83ad71)