Package org.springframework.context.annotation

Annotation Interface Lazy

@Target({TYPE,METHOD,CONSTRUCTOR,PARAMETER,FIELD}) @Retention(RUNTIME) @Documented public @interface Lazy
Indicates whether a bean is to be lazily initialized.

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 the affected dependency, caching it on first access in case of a singleton or re-resolving it on every access otherwise. This is 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

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    boolean
    value
    Whether lazy initialization should occur.

  • Element Details

    • value

      boolean value
      Whether lazy initialization should occur.
      Default:
      true