AttributeAccessor (Spring Framework 5.2.12.RELEASE API)

所有已知子接口:
AnnotatedBeanDefinition, BeanDefinition, TestContext
所有已知实现类:
AbstractBeanDefinition, AnnotatedGenericBeanDefinition, AttributeAccessorSupport, AutowireCandidateQualifier, BeanMetadataAttributeAccessor, ChildBeanDefinition, DefaultTestContext, GenericBeanDefinition, PropertyValue, RootBeanDefinition, ScannedGenericBeanDefinition
```
public interface AttributeAccessor
```
Interface defining a generic contract for attaching and accessing metadata to/from arbitrary objects.
从以下版本开始:
2.0
作者:
Rob Harrop

方法概要

所有方法实例方法抽象方法
修饰符和类型	方法	说明
`String[]`	`attributeNames()`	Return the names of all attributes.
`Object`	`getAttribute(String name)`	Get the value of the attribute identified by `name`.
`boolean`	`hasAttribute(String name)`	Return `true` if the attribute identified by `name` exists.
`Object`	`removeAttribute(String name)`	Remove the attribute identified by `name` and return its value.
`void`	`setAttribute(String name, Object value)`	Set the attribute defined by `name` to the supplied `value`.

- 方法详细资料
  - setAttribute
```
void setAttribute(String name,
                  @Nullable
                  Object value)
```
    Set the attribute defined by name to the supplied value. If value is null, the attribute is removed.
    In general, users should take care to prevent overlaps with other metadata attributes by using fully-qualified names, perhaps using class or package names as prefix.
    参数:
    name - the unique attribute key
    value - the attribute value to be attached
  - getAttribute
```
@Nullable
Object getAttribute(String name)
```
    Get the value of the attribute identified by name. Return null if the attribute doesn't exist.
    参数:
    name - the unique attribute key
    返回:
    the current value of the attribute, if any
  - removeAttribute
```
@Nullable
Object removeAttribute(String name)
```
    Remove the attribute identified by name and return its value. Return null if no attribute under name is found.
    参数:
    name - the unique attribute key
    返回:
    the last value of the attribute, if any
  - hasAttribute
```
boolean hasAttribute(String name)
```
    Return true if the attribute identified by name exists. Otherwise return false.
    参数:
    name - the unique attribute key
  - attributeNames
```
String[] attributeNames()
```
    Return the names of all attributes.