Adaptive (Apache Dubbo 2.7.11 API)

```
@Documented
@Retention(RUNTIME)
@Target({TYPE,METHOD})
public @interface Adaptive
```
Provide helpful information for ExtensionLoader to inject dependency extension instance.

另请参阅:

ExtensionLoader, URL

- 可选元素概要
  
  可选元素
  修饰符和类型可选元素说明
  
  String[] value
  Decide which target extension to be injected.

- 元素详细资料
  - value
```
String[] value
```
    Decide which target extension to be injected. The name of the target extension is decided by the parameter passed in the URL, and the parameter names are given by this method.
    If the specified parameters are not found from URL, then the default extension will be used for dependency injection (specified in its interface's SPI).
    For example, given String[] {"key1", "key2"}:
    
    find parameter 'key1' in URL, use its value as the extension's name
    
    try 'key2' for extension's name if 'key1' is not found (or its value is empty) in URL
    
    use default extension if 'key2' doesn't exist either
    
    otherwise, throw IllegalStateException
    
    If the parameter names are empty, then a default parameter name is generated from interface's class name with the rule: divide classname from capital char into several parts, and separate the parts with dot '.', for example, for org.apache.dubbo.xxx.YyyInvokerWrapper, the generated name is String[] {"yyy.invoker.wrapper"}.
    返回:
    
    parameter names in URL
    
    默认值:
    
    {}