mediumConceptScenarioMidSenior
A singleton service depends on a prototype-scoped bean, and every caller gets the same instance. Why, and how do you get a fresh one per use?
Prototype scope means a new instance per request to the container, and a singleton asks once, at construction. Inject an ObjectProvider and call getObject() each time you need a fresh instance. A scoped proxy also works, but on a prototype it creates a new target on every method call, which is rarely what you meant.
4 min readUpdated 2026-10-09Target archetype: Enterprise Captive, Product Startup
Answer
Short answer
The singleton is created once, so its dependencies are resolved once. Prototype scope gives a new instance each time the container is asked, but a constructor-injected field asks exactly one time. Inject ObjectProvider<T> and call getObject() wherever you need a fresh instance; avoid a scoped proxy here unless you understand that it fetches a new target on every method call.
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Likely follow-ups
- Your request-scoped bean is used from an @Async method. What fails, and why does the proxy not help?
- Why do @Lookup methods not work on a bean returned from an @Bean factory method?
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- How would you pass a per-call argument, such as a customer id, into the constructor of each new prototype instance?
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