org.springframework.beans.factory.config

## 类 PropertyPathFactoryBean

- java.lang.Object
- - org.springframework.beans.factory.config.PropertyPathFactoryBean

- 所有已实现的接口:
    Aware, BeanFactoryAware, BeanNameAware, FactoryBean<Object>

      public class PropertyPathFactoryBean
      extends Object
      implements FactoryBean<Object>, BeanNameAware, BeanFactoryAware

  `FactoryBean` that evaluates a property path on a given target object.

  The target object can be specified directly or via a bean name.

  Usage examples:

      <!-- target bean to be referenced by name -->
       <bean id="tb" class="org.springframework.beans.TestBean" singleton="false">
         <property name="age" value="10"/>
         <property name="spouse">
           <bean class="org.springframework.beans.TestBean">
             <property name="age" value="11"/>
           </bean>
         </property>
       </bean>

       <!-- will result in 12, which is the value of property 'age' of the inner bean -->
       <bean id="propertyPath1" class="org.springframework.beans.factory.config.PropertyPathFactoryBean">
         <property name="targetObject">
           <bean class="org.springframework.beans.TestBean">
             <property name="age" value="12"/>
           </bean>
         </property>
         <property name="propertyPath" value="age"/>
       </bean>

       <!-- will result in 11, which is the value of property 'spouse.age' of bean 'tb' -->
       <bean id="propertyPath2" class="org.springframework.beans.factory.config.PropertyPathFactoryBean">
         <property name="targetBeanName" value="tb"/>
         <property name="propertyPath" value="spouse.age"/>
       </bean>

       <!-- will result in 10, which is the value of property 'age' of bean 'tb' -->
       <bean id="tb.age" class="org.springframework.beans.factory.config.PropertyPathFactoryBean"/>

  If you are using Spring 2.0 and XML Schema support in your configuration file(s), you can also use the following style of configuration for property path access. (See also the appendix entitled 'XML Schema-based configuration' in the Spring reference manual for more examples.)

       <!-- will result in 10, which is the value of property 'age' of bean 'tb' -->
       <util:property-path id="name" path="testBean.age"/>

  Thanks to Matthias Ernst for the suggestion and initial prototype!
  从以下版本开始:
    1.1.2
  作者:
    Juergen Hoeller
  另请参阅:
    `setTargetObject(java.lang.Object)`, `setTargetBeanName(java.lang.String)`, `setPropertyPath(java.lang.String)`

- - ### 构造器概要

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

  - ### 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
    --- | ---
    `Object` | `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()` While this FactoryBean will often be used for singleton targets, the invoked getters for the property path might return a new object for each call, so we have to assume that we're not returning the same object for each `getObject()` call.
    `void` | `setBeanFactory(BeanFactory beanFactory)` Callback that supplies the owning factory to a bean instance.
    `void` | `setBeanName(String beanName)` The bean name of this PropertyPathFactoryBean will be interpreted as "beanName.property" pattern, if neither "targetObject" nor "targetBeanName" nor "propertyPath" have been specified.
    `void` | `setPropertyPath(String propertyPath)` Specify the property path to apply to the target.
    `void` | `setResultType(Class<?> resultType)` Specify the type of the result from evaluating the property path.
    `void` | `setTargetBeanName(String targetBeanName)` Specify the name of a target bean to apply the property path to.
    `void` | `setTargetObject(Object targetObject)` Specify a target object to apply the property path to.

    - ### 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

    - #### PropertyPathFactoryBean

          public PropertyPathFactoryBean()

  - ### 方法详细资料

    - #### setTargetObject

          public void setTargetObject(Object targetObject)

      Specify a target object to apply the property path to. Alternatively, specify a target bean name.
      参数:
        `targetObject` - a target object, for example a bean reference or an inner bean
      另请参阅:
        `setTargetBeanName(java.lang.String)`

    - #### setTargetBeanName

          public void setTargetBeanName(String targetBeanName)

      Specify the name of a target bean to apply the property path to. Alternatively, specify a target object directly.
      参数:
        `targetBeanName` - the bean name to be looked up in the containing bean factory (e.g. "testBean")
      另请参阅:
        `setTargetObject(java.lang.Object)`

    - #### setPropertyPath

          public void setPropertyPath(String propertyPath)

      Specify the property path to apply to the target.
      参数:
        `propertyPath` - the property path, potentially nested (e.g. "age" or "spouse.age")

    - #### setResultType

          public void setResultType(Class<?> resultType)

      Specify the type of the result from evaluating the property path.

      Note: This is not necessary for directly specified target objects or singleton target beans, where the type can be determined through introspection. Just specify this in case of a prototype target, provided that you need matching by type (for example, for autowiring).

      参数:
        `resultType` - the result type, for example "java.lang.Integer"

    - #### setBeanName

          public void setBeanName(String beanName)

      The bean name of this PropertyPathFactoryBean will be interpreted as "beanName.property" pattern, if neither "targetObject" nor "targetBeanName" nor "propertyPath" have been specified. This allows for concise bean definitions with just an id/name.
      指定者:
        `setBeanName` 在接口中 `BeanNameAware`
      参数:
        `beanName` - the name of the bean in the factory. Note that this name is the actual bean name used in the factory, which may differ from the originally specified name: in particular for inner bean names, the actual bean name might have been made unique through appending "#..." suffixes. Use the `BeanFactoryUtils.originalBeanName(String)` method to extract the original bean name (without suffix), if desired.

    - #### setBeanFactory

          public void setBeanFactory(BeanFactory beanFactory)

      从接口复制的说明: `BeanFactoryAware`
      Callback that supplies the owning factory to a bean instance.

      Invoked after the population of normal bean properties but before an initialization callback such as `InitializingBean.afterPropertiesSet()` or a custom init-method.

      指定者:
        `setBeanFactory` 在接口中 `BeanFactoryAware`
      参数:
        `beanFactory` - owning BeanFactory (never `null`). The bean can immediately call methods on the factory.
      另请参阅:
        `BeanInitializationException`

    - #### getObject

          @Nullable
          public Object getObject()
                                      throws BeansException

      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<Object>`
      返回:
        an instance of the bean (can be `null`)
      抛出:
        `BeansException`
      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<Object>`
      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>)`

    - #### isSingleton

          public boolean isSingleton()

      While this FactoryBean will often be used for singleton targets, the invoked getters for the property path might return a new object for each call, so we have to assume that we're not returning the same object for each `getObject()` call.
      指定者:
        `isSingleton` 在接口中 `FactoryBean<Object>`
      返回:
        whether the exposed object is a singleton
      另请参阅:
        `FactoryBean.getObject()`, `SmartFactoryBean.isPrototype()`