When Should You Use @Autowired vs @Resource? A Deep Dive into Spring Dependency Injection

Warning

Recently a new teammate used @Autowired for dependency injection and got a yellow warning in IntelliJ IDEA, while @Resource did not. The author shares insights on this situation.

Difference between @Autowired and @Resource

Origin

@Resource is defined in JSR‑250 (2006).

@Autowired was introduced in Spring 2.5 (2007).

@Resource is a standard JSR, while @Autowired is Spring‑specific. Because @Autowired appeared later, it must provide something that @Resource cannot express.

Usage

Injection styles

Developers most often use field injection, but constructor injection and setter injection also exist. @Autowired supports constructor injection; @Resource does not.

Configurable attributes

@Autowired

supports the required attribute.

@Resource

provides seven additional attributes (name, type, etc.).

Bean lookup strategy

@Autowired

: type‑first; if multiple beans of the same type exist, it falls back to bean name. @Resource: name‑first; if the specified name is not found, it searches by type.

Lookup process

@Autowired

@Resource

Thoughts

For most developers the differences are minor. Although @Autowired adds constructor injection, field injection is already very convenient. The main distinction lies in the bean lookup strategy: @Autowired defaults to byType, while @Resource defaults to byName, giving @Resource a more deterministic resolution.

Conclusion

IDE warns against field injection (“Field injection is not recommended”). Switching to @Resource only silences the warning without solving the underlying issue. The recommended practice is to use constructor injection (optionally with Lombok) to keep class responsibilities clear.