org.springframework.beans.factory.access

## Interface BeanFactoryLocator

- All Known Implementing Classes:
    ContextJndiBeanFactoryLocator, ContextSingletonBeanFactoryLocator, SingletonBeanFactoryLocator

      public interface BeanFactoryLocator

  Defines a contract for the lookup, use, and release of a `BeanFactory`, or a `BeanFactory` subclass such as an `ApplicationContext`.

  Where this interface is implemented as a singleton class such as `SingletonBeanFactoryLocator`, the Spring team strongly suggests that it be used sparingly and with caution. By far the vast majority of the code inside an application is best written in a Dependency Injection style, where that code is served out of a `BeanFactory`/`ApplicationContext` container, and has its own dependencies supplied by the container when it is created. However, even such a singleton implementation sometimes has its use in the small glue layers of code that is sometimes needed to tie other code together. For example, third party code may try to construct new objects directly, without the ability to force it to get these objects out of a `BeanFactory`. If the object constructed by the third party code is just a small stub or proxy, which then uses an implementation of this class to get a `BeanFactory` from which it gets the real object, to which it delegates, then proper Dependency Injection has been achieved.

  As another example, in a complex J2EE app with multiple layers, with each layer having its own `ApplicationContext` definition (in a hierarchy), a class like `SingletonBeanFactoryLocator` may be used to demand load these contexts.

  Author:
    Colin Sampaleanu
  See Also:
    `BeanFactory`, `DefaultLocatorFactory`, `ApplicationContext`

- - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `BeanFactoryReference` | `useBeanFactory(String factoryKey)` Use the `BeanFactory` (or derived interface such as `ApplicationContext`) specified by the `factoryKey` parameter.

- - ### Method Detail

    - #### useBeanFactory

          BeanFactoryReference useBeanFactory(String factoryKey)
                                              throws BeansException

      Use the `BeanFactory` (or derived interface such as `ApplicationContext`) specified by the `factoryKey` parameter.

      The definition is possibly loaded/created as needed.

      Parameters:
        `factoryKey` - a resource name specifying which `BeanFactory` the `BeanFactoryLocator` must return for usage. The actual meaning of the resource name is specific to the implementation of `BeanFactoryLocator`.
      Returns:
        the `BeanFactory` instance, wrapped as a `BeanFactoryReference` object
      Throws:
        `BeansException` - if there is an error loading or accessing the `BeanFactory`