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Modernize the lazy-initialized beans refdoc section

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Closes gh-32767
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Sébastien Deleuze
2024-05-06 17:08:49 +02:00
parent c6459b40e4
commit 04944a1f56
9 changed files with 197 additions and 16 deletions
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24
framework-docs/modules/ROOT/pages/core/beans/dependencies/factory-lazy-init.adoc
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@@ -10,33 +10,25 @@ pre-instantiation of a singleton bean by marking the bean definition as being
lazy-initialized. A lazy-initialized bean tells the IoC container to create a bean
instance when it is first requested, rather than at startup.
In XML, this behavior is controlled by the `lazy-init` attribute on the `<bean/>`
element, as the following example shows:
This behavior is controlled by the `@Lazy` annotation or in XML the `lazy-init` attribute on the `<bean/>` element, as
the following example shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<bean id="lazy" class="com.something.ExpensiveToCreateBean" lazy-init="true"/>
<bean name="not.lazy" class="com.something.AnotherBean"/>
----
include-code::./ApplicationConfiguration[tag=snippet,indent=0]
When the preceding configuration is consumed by an `ApplicationContext`, the `lazy` bean
is not eagerly pre-instantiated when the `ApplicationContext` starts,
whereas the `not.lazy` bean is eagerly pre-instantiated.
whereas the `notLazy` one is eagerly pre-instantiated.
However, when a lazy-initialized bean is a dependency of a singleton bean that is
not lazy-initialized, the `ApplicationContext` creates the lazy-initialized bean at
startup, because it must satisfy the singleton's dependencies. The lazy-initialized bean
is injected into a singleton bean elsewhere that is not lazy-initialized.
You can also control lazy-initialization at the container level by using the
`default-lazy-init` attribute on the `<beans/>` element, as the following example shows:
You can also control lazy-initialization for a set of beans by using the `@Lazy` annotation on your `@Configuration`
annotated class or in XML using the `default-lazy-init` attribute on the `<beans/>` element, as the following example
shows:
[source,xml,indent=0,subs="verbatim,quotes"]
----
<beans default-lazy-init="true">
<!-- no beans will be pre-instantiated... -->
</beans>
----
include-code::./LazyConfiguration[tag=snippet,indent=0]