程序包 com.alibaba.dubbo.common

注释类型 Extension

  • @Deprecated
@Documented
@Retention(RUNTIME)
@Target(TYPE)
public @interface Extension
    已过时。
    because it's too general, switch to use SPI
    Marker for extension interface

    Changes on extension configuration file
    Use Protocol as an example, its configuration file 'META-INF/dubbo/com.xxx.Protocol' is changes from: 
         com.foo.XxxProtocol
     com.foo.YyyProtocol

    to key-value pair 

         xxx=com.foo.XxxProtocol
     yyy=com.foo.YyyProtocol

    The reason for this change is:

    If there's third party library referenced by static field or by method in extension implementation, its class will fail to initialize if the third party library doesn't exist. In this case, dubbo cannot figure out extension's id therefore cannot be able to map the exception information with the extension, if the previous format is used.

    For example:

    Fails to load Extension("mina"). When user configure to use mina, dubbo will complain the extension cannot be loaded, instead of reporting which extract extension implementation fails and the extract reason.

    • 可选元素概要

      可选元素 
      修饰符和类型 可选元素 说明
      String value
      已过时。