distinguish "none found" from "several found" in NoSuchBeanDefinitionException [SPR-10194]

[spring-projects-issues]

Dan Lipofsky opened SPR-10194 and commented

ApplicationContext.getBean(Class) throws NoSuchBeanDefinitionException in 2 cases: when no beans are found and when more than one matching beans are found. The only way to tell the difference is by parsing the message (which is hardly reliable, the message could change). I would like a better way to programmatically tell the difference.

One way to do this would be to add a boolean flag (e.g. isNonUnique()) or an integer flag (e.g. getNumberOfBeansFound()) to the exception.

However, a better way might be a different exception, e.g. NoUniqueBeanException. This can be a subclass of NoSuchBeanDefinitionException for backwards compatibility.

---

Affects: 3.2 GA

Referenced from: commits 8f103c2, ece727b

[spring-projects-issues]

Juergen Hoeller commented

Good point! I've introduced a NoUniqueBeanDefinitionException as a dedicated subclass of NoSuchBeanDefinitionException, with a new getNumberOfBeansFound accessor available on the base class (always returning 0) and overridden to return a number higher than 1 in NoUniqueBeanDefinitionException itself.

Juergen