Spring dependency injections

Here's my list of handy links that I found useful when learning about dependency injections in Spring.

Spring documentation: The IoC container

StackOverflow: Why is my Spring @Autowired field null?

StackOverflow: Spring: Why is setter not called in spite of @Autowired annotation

StackOverflow: Spring @Autowired and Singletons

StackOverflow: How does autowiring work in Spring?

StackOverflow: Spring constructor injection shows null When accessing it on methods

StackOverflow: Singleton and @Autowired returning NULL

Baeldung: Guide to Spring @Autowired

Reflectoring.io: Why You Should Use Constructor Injection in Spring

More of Less blog by Steve Claridge: Two reasons why your Spring @Autowired component is null