Is spring default scope singleton or not?

Question

Could you please explain why Spring is creating two objects for the configuration of beans shown below, since by default spring default scope is singleton?

The Sprin

Answer 1

Like others have mentioned, two beans should be created from the code you posted. Singletons are defined as follows (from the Spring documentation: Singleton Scope)

Only one shared instance of a singleton bean is managed, and all requests for beans with an id or ids matching that bean definition result in that one specific bean instance being returned by the Spring container.

To add clarity to this, the meaning behind "shared instance" is explained in the paragraph that follows the one above:

all subsequent requests and references for that named bean return the cached object

When a singleton bean is created, only one bean object is instantiated and cached. This refers only to the bean, not to whatever class the bean may be an instance of. For example,

In this made up configuration, "myOtherBean1" and "myOtherBean2" have references to the same "myBean" bean therefore the same "myPackage.myClass" instance. If you changed the code to add a second "myPackage.myClass" bean, it would be distinct from "myBean".

To fully understand this, also refer to the other Spring scope: the prototype. From the Spring documentation for Prototype Scope:

The non-singleton, prototype scope of bean deployment results in the creation of a new bean instance every time a request for that specific bean is made.

This means that if we were to use the same Spring XML as above, "myOtherBean1" and "myOtherBean2" would each receive their own distinct copies of "myBean" which is still just an instance of "myPackage.myClass".