org.springframework.beans.factory.config

## 类 PropertiesFactoryBean

- java.lang.Object
- - org.springframework.core.io.support.PropertiesLoaderSupport
  - - org.springframework.beans.factory.config.PropertiesFactoryBean

- 所有已实现的接口:
    FactoryBean<Properties>, InitializingBean

      public class PropertiesFactoryBean
      extends org.springframework.core.io.support.PropertiesLoaderSupport
      implements FactoryBean<Properties>, InitializingBean

  Allows for making a properties file from a classpath location available as Properties instance in a bean factory. Can be used to populate any bean property of type Properties via a bean reference.

  Supports loading from a properties file and/or setting local properties on this FactoryBean. The created Properties instance will be merged from loaded and local values. If neither a location nor local properties are set, an exception will be thrown on initialization.

  Can create a singleton or a new object on each request. Default is a singleton.

  作者:
    Juergen Hoeller
  另请参阅:
    `PropertiesLoaderSupport.setLocation(org.springframework.core.io.Resource)`, `PropertiesLoaderSupport.setProperties(java.util.Properties)`, `PropertiesLoaderSupport.setLocalOverride(boolean)`, `Properties`

- - ### 字段概要

    - ### 从类继承的字段 org.springframework.core.io.support.PropertiesLoaderSupport

      `localOverride, localProperties, logger`

  - ### 构造器概要

    构造器
    构造器和说明
    `PropertiesFactoryBean()`

  - ### 方法概要

    所有方法 实例方法 具体方法
    限定符和类型 | 方法和说明
    --- | ---
    `void` | `afterPropertiesSet()` Invoked by the containing `BeanFactory` after it has set all bean properties and satisfied `BeanFactoryAware`, `ApplicationContextAware` etc.
    `protected Properties` | `createProperties()` Template method that subclasses may override to construct the object returned by this factory.
    `Properties` | `getObject()` Return an instance (possibly shared or independent) of the object managed by this factory.
    `Class<Properties>` | `getObjectType()` Return the type of object that this FactoryBean creates, or `null` if not known in advance.
    `boolean` | `isSingleton()` Is the object managed by this factory a singleton?
    `void` | `setSingleton(boolean singleton)` Set whether a shared 'singleton' Properties instance should be created, or rather a new Properties instance on each request.

    - ### 从类继承的方法 org.springframework.core.io.support.PropertiesLoaderSupport

      `loadProperties, mergeProperties, setFileEncoding, setIgnoreResourceNotFound, setLocalOverride, setLocation, setLocations, setProperties, setPropertiesArray, setPropertiesPersister`

    - ### 从类继承的方法 java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### 构造器详细资料

    - #### PropertiesFactoryBean

          public PropertiesFactoryBean()

  - ### 方法详细资料

    - #### setSingleton

          public final void setSingleton(boolean singleton)

      Set whether a shared 'singleton' Properties instance should be created, or rather a new Properties instance on each request.

      Default is "true" (a shared singleton).

    - #### isSingleton

          public final boolean isSingleton()

      从接口复制的说明: `FactoryBean`
      Is the object managed by this factory a singleton? That is, will `FactoryBean.getObject()` always return the same object (a reference that can be cached)?

      NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from `getObject()` might get cached by the owning BeanFactory. Hence, do not return `true` unless the FactoryBean always exposes the same reference.

      The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

      NOTE: This method returning `false` does not necessarily indicate that returned objects are independent instances. An implementation of the extended `SmartFactoryBean` interface may explicitly indicate independent instances through its `SmartFactoryBean.isPrototype()` method. Plain `FactoryBean` implementations which do not implement this extended interface are simply assumed to always return independent instances if the `isSingleton()` implementation returns `false`.

      The default implementation returns `true`, since a `FactoryBean` typically manages a singleton instance.

      指定者:
        `isSingleton` 在接口中 `FactoryBean<Properties>`
      返回:
        whether the exposed object is a singleton
      另请参阅:
        `FactoryBean.getObject()`, `SmartFactoryBean.isPrototype()`

    - #### afterPropertiesSet

          public final void afterPropertiesSet()
                                        throws IOException

      从接口复制的说明: `InitializingBean`
      Invoked by the containing `BeanFactory` after it has set all bean properties and satisfied `BeanFactoryAware`, `ApplicationContextAware` etc.

      This method allows the bean instance to perform validation of its overall configuration and final initialization when all bean properties have been set.

      指定者:
        `afterPropertiesSet` 在接口中 `InitializingBean`
      抛出:
        `IOException`

    - #### getObject

          @Nullable
          public final Properties getObject()
                                                throws IOException

      从接口复制的说明: `FactoryBean`
      Return an instance (possibly shared or independent) of the object managed by this factory.

      As with a `BeanFactory`, this allows support for both the Singleton and Prototype design pattern.

      If this FactoryBean is not fully initialized yet at the time of the call (for example because it is involved in a circular reference), throw a corresponding `FactoryBeanNotInitializedException`.

      As of Spring 2.0, FactoryBeans are allowed to return `null` objects. The factory will consider this as normal value to be used; it will not throw a FactoryBeanNotInitializedException in this case anymore. FactoryBean implementations are encouraged to throw FactoryBeanNotInitializedException themselves now, as appropriate.

      指定者:
        `getObject` 在接口中 `FactoryBean<Properties>`
      返回:
        an instance of the bean (can be `null`)
      抛出:
        `IOException`
      另请参阅:
        `FactoryBeanNotInitializedException`

    - #### getObjectType

          public Class<Properties> getObjectType()

      从接口复制的说明: `FactoryBean`
      Return the type of object that this FactoryBean creates, or `null` if not known in advance.

      This allows one to check for specific types of beans without instantiating objects, for example on autowiring.

      In the case of implementations that are creating a singleton object, this method should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

      This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

      NOTE: Autowiring will simply ignore FactoryBeans that return `null` here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

      指定者:
        `getObjectType` 在接口中 `FactoryBean<Properties>`
      返回:
        the type of object that this FactoryBean creates, or `null` if not known at the time of the call
      另请参阅:
        `ListableBeanFactory.getBeansOfType(java.lang.Class<T>)`

    - #### createProperties

          protected Properties createProperties()
                                         throws IOException

      Template method that subclasses may override to construct the object returned by this factory. The default implementation returns the plain merged Properties instance.

      Invoked on initialization of this FactoryBean in case of a shared singleton; else, on each `getObject()` call.

      返回:
        the object returned by this factory
      抛出:
        `IOException` - if an exception occurred during properties loading
      另请参阅:
        `PropertiesLoaderSupport.mergeProperties()`