CODEWITHSUNDEEP
javaspringscopejavabeans
Vladimir
Vladimir

Reputation: 13153

Spring beans with scope prototype

Suppose have following beach definition:

<bean id="singletonBean" class="...">
   <property name="instanceBean" ref="instanceBean"/>
</bean>

<bean id="instanceBean" class="..." scope="prototype"/>

When I call:

singletonBean = context.getBean("singletonBean");

...some code...

singletonBean = context.getBean("singletonBean");

Would property instanceBean of singletonBean be initialized again or it would just use already created singleton?

Upvotes: 2

Views: 3234

Answers (3)

Manu
Manu

Reputation: 3625

When invoked context.getBean("singletonBean") always it contains the same instance of instanceBean, though the scope is prototype in the bean definition.

On the contrary if the container bean is of scope prototype and it refers to a bean which is defined with scope singleton, always the inner bean would be singleton. Eg:-

<bean id="outer" class="OuterBean" scope="prototype">
   <property name="innerBean" ref="inner" />
</bean>
<bean id="inner" class="InnerBean" scope="singleton"/>

OuterBean outer1 = (OuterBean) context.getBean("outer");
OuterBean outer2 = (OuterBean) context.getBean("outer");

Here both outer1 and outer2 will contain same instance of InnerBean.

In a multitheaded environment, if innerBean holds any shared data, it can lead to race condition.

Upvotes: 0

Alois Cochard
Alois Cochard

Reputation: 9862

Would just use already created singleton.

A prototyped inner bean of a singleton won't be recreated each time you get the singleton from context. The singleton and all is references are created one for all.

But context.getBean("instanceBean"); would give you a new since scope is 'prototype'.

Upvotes: 4

Michel
Michel

Reputation: 9440

instanceBean is set only once on startup, so you can get the instanceBean by singletonBean.getInstanceBean() if you like.

Upvotes: 0

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