Annotation Interface Lazy
May be used on any class directly or indirectly annotated with @Component
or on methods annotated with
@Bean
.
If this annotation is not present on a @Component
or @Bean
definition,
eager initialization will occur. If present and set to true
, the @Bean
or
@Component
will not be initialized until referenced by another bean or explicitly
retrieved from the enclosing BeanFactory
. If present and set to false
, the bean will be instantiated on
startup by bean factories that perform eager initialization of singletons.
If Lazy is present on a @Configuration
class, this
indicates that all @Bean
methods within that @Configuration
should be lazily initialized. If @Lazy
is present and false on a @Bean
method within a @Lazy
-annotated @Configuration
class, this indicates
overriding the 'default lazy' behavior and that the bean should be eagerly initialized.
In addition to its role for component initialization, this annotation may also be placed
on injection points marked with Autowired
or Inject
: In that context, it leads to the creation of a
lazy-resolution proxy for all affected dependencies, as an alternative to using
ObjectFactory
or Provider
.
Please note that such a lazy-resolution proxy will always be injected; if the target
dependency does not exist, you will only be able to find out through an exception on
invocation. As a consequence, such an injection point results in unintuitive behavior
for optional dependencies. For a programmatic equivalent, allowing for lazy references
with more sophistication, consider ObjectProvider
.
- Since:
- 3.0
- Author:
- Chris Beams, Juergen Hoeller
- See Also:
-
Optional Element Summary
Modifier and TypeOptional ElementDescriptionboolean
Whether lazy initialization should occur.
-
Element Details
-
value
boolean valueWhether lazy initialization should occur.- Default:
- true
-