Package org.apache.dubbo.common.extension

Annotation Type SPI

@Documented @Retention(RUNTIME) @Target(TYPE) public @interface 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 changed 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.

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    ExtensionScope
    scope
    scope of SPI, default value is application scope.
    String
    value
    default extension name

  • Element Details

    • value

      String value
      default extension name
      Default:
      ""

    • scope

      ExtensionScope scope
      scope of SPI, default value is application scope.
      Default:
      APPLICATION