/* | |
* Licensed to the Apache Software Foundation (ASF) under one or more | |
* contributor license agreements. See the NOTICE file distributed with | |
* this work for additional information regarding copyright ownership. | |
* The ASF licenses this file to You under the Apache License, Version 2.0 | |
* (the "License"); you may not use this file except in compliance with | |
* the License. You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, | |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
*/ | |
package com.alibaba.dubbo.common; | |
import java.lang.annotation.Documented; | |
import java.lang.annotation.ElementType; | |
import java.lang.annotation.Retention; | |
import java.lang.annotation.RetentionPolicy; | |
import java.lang.annotation.Target; | |
/** | |
* Marker for extension interface | |
* <p/> | |
* Changes on extension configuration file <br/> | |
* Use <code>Protocol</code> as an example, its configuration file 'META-INF/dubbo/com.xxx.Protocol' is changes from: <br/> | |
* <pre> | |
* com.foo.XxxProtocol | |
* com.foo.YyyProtocol | |
* </pre> | |
* <p> | |
* to key-value pair <br/> | |
* <pre> | |
* xxx=com.foo.XxxProtocol | |
* yyy=com.foo.YyyProtocol | |
* </pre> | |
* <br/> | |
* The reason for this change is: | |
* <p> | |
* 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. | |
* <p/> | |
* For example: | |
* <p> | |
* 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. | |
* </p> | |
* | |
* @deprecated because it's too general, switch to use {@link com.alibaba.dubbo.common.extension.SPI} | |
*/ | |
@Deprecated | |
@Documented | |
@Retention(RetentionPolicy.RUNTIME) | |
@Target({ElementType.TYPE}) | |
public @interface Extension { | |
/** | |
* @deprecated | |
*/ | |
@Deprecated | |
String value() default ""; | |
} |