org.springframework.beans.factory.config

## 类 YamlPropertiesFactoryBean

- java.lang.Object
- - org.springframework.beans.factory.config.YamlProcessor
  - - org.springframework.beans.factory.config.YamlPropertiesFactoryBean

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

      public class YamlPropertiesFactoryBean
      extends YamlProcessor
      implements FactoryBean<Properties>, InitializingBean

  Factory for `Properties` that reads from a YAML source, exposing a flat structure of String property values.

  YAML is a nice human-readable format for configuration, and it has some useful hierarchical properties. It's more or less a superset of JSON, so it has a lot of similar features.

  Note: All exposed values are of type `String` for access through the common `Properties.getProperty(java.lang.String)` method (e.g. in configuration property resolution through `PropertiesLoaderSupport.setProperties(Properties)`). If this is not desirable, use `YamlMapFactoryBean` instead.

  The Properties created by this factory have nested paths for hierarchical objects, so for instance this YAML

       environments:
         dev:
           url: https://dev.bar.com
           name: Developer Setup
         prod:
           url: https://foo.bar.com
           name: My Cool App

  is transformed into these properties:

       environments.dev.url=https://dev.bar.com
       environments.dev.name=Developer Setup
       environments.prod.url=https://foo.bar.com
       environments.prod.name=My Cool App

  Lists are split as property keys with `[]` dereferencers, for example this YAML:

       servers:
       - dev.bar.com
       - foo.bar.com

  becomes properties like this:

       servers[0]=dev.bar.com
       servers[1]=foo.bar.com

  Requires SnakeYAML 1.18 or higher, as of Spring Framework 5.0.6.

  从以下版本开始:
    4.1
  作者:
    Dave Syer, Stephane Nicoll, Juergen Hoeller

- - ### 嵌套类概要

    - ### 从类继承的嵌套类/接口 org.springframework.beans.factory.config.YamlProcessor

      `YamlProcessor.DocumentMatcher, YamlProcessor.MatchCallback, YamlProcessor.MatchStatus, YamlProcessor.ResolutionMethod, YamlProcessor.StrictMapAppenderConstructor`

  - ### 构造器概要

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

  - ### 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<?>` | `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 if a singleton should be created, or a new object on each request otherwise.

    - ### 从类继承的方法 org.springframework.beans.factory.config.YamlProcessor

      `createYaml, getFlattenedMap, process, setDocumentMatchers, setMatchDefault, setResolutionMethod, setResources`

    - ### 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

    - #### YamlPropertiesFactoryBean

          public YamlPropertiesFactoryBean()

  - ### 方法详细资料

    - #### setSingleton

          public void setSingleton(boolean singleton)

      Set if a singleton should be created, or a new object on each request otherwise. Default is `true` (a singleton).

    - #### isSingleton

          public 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 void afterPropertiesSet()

      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`

    - #### getObject

          @Nullable
          public Properties getObject()

      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`)
      另请参阅:
        `FactoryBeanNotInitializedException`

    - #### getObjectType

          public Class<?> 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()

      Template method that subclasses may override to construct the object returned by this factory. The default implementation returns a properties with the content of all resources.

      Invoked lazily the first time `getObject()` is invoked in case of a shared singleton; else, on each `getObject()` call.

      返回:
        the object returned by this factory
      另请参阅:
        `YamlProcessor.process(MatchCallback)`