Question

How can I assure that a Spring bean is a singleton?

I’d implement the Interfaces ApplicationContext, InitializingBean and BeanNameAware.

In afterPropertiesSet() I’d call isSingleton(String) with the Bean’s name.

Is there another way to make sure that a Bean is a singleton?

Because according to the API:

Note that it is not usually recommended that an object depend on its
bean name, as this represents a potentially brittle dependence on
external configuration, as well as a possibly unnecessary dependence
on a Spring API.

Answer 1

If i recall correctly, a spring-managed bean will be a singleton by default (for current versions of the spring-library), unless you define the scope to be of type ‘prototype’.

Check: Default scope of spring beans

Quote:

The singleton scope is the default scope in Spring