dubbo spi + adaptive 源碼分析

總結:?Protocolrefprotocol = ExtensionLoader.getExtensionLoader(Protocol.class).getAdaptiveExtension();

首先會生成自適應ExtensionFactory ,根據URL可適配的工廠包含兩個spi 和 spring;

然后才會真正的去生成Protocol的自適應對象(代碼生成,并運行時編譯),其可適配的對象就比較多了,例如dubbo,http等等

AAA 1 默認首次執行

ExtensionFactory 自適應實現

private ExtensionLoader(Class type) {

? ? this.type = type;

? ? objectFactory = (type == ExtensionFactory.class ? null : ExtensionLoader.getExtensionLoader(ExtensionFactory.class).getAdaptiveExtension());

}


META-INF/dubbo/internal/com.alibaba.dubbo.common.extension.ExtensionFactory

讀取:指定包下的擴展配置

ExtensionLoader.class.getClassLoader()

urls = classLoader.getResources(fileName);

BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream(), "utf-8"));

META-INF/dubbo/internal/com.alibaba.dubbo.common.extension.ExtensionFactory

文件內容:

spring=com.alibaba.dubbo.config.spring.extension.SpringExtensionFactory

adaptive=com.alibaba.dubbo.common.extension.factory.AdaptiveExtensionFactory

spi=com.alibaba.dubbo.common.extension.factory.SpiExtensionFactory


1 解析url

spring=com.alibaba.dubbo.config.spring.extension.SpringExtensionFactory

name=spring

line=com.alibaba.dubbo.config.spring.extension.SpringExtensionFactory

Class clazz = Class.forName(line, true, classLoader);

interface

type=com.alibaba.dubbo.common.extension.ExtensionFactory

放入extensionClasses? cache: clazz = com.alibaba.dubbo.config.spring.extension.SpringExtensionFactory

2 解析url

adaptive=com.alibaba.dubbo.common.extension.factory.AdaptiveExtensionFactory

name=adaptive? 包含SPI 和 Spring 兩個擴展工廠

line=com.alibaba.dubbo.common.extension.factory.AdaptiveExtensionFactory

緩存adaptive--class不會放到extensionClasses 因為這個累就是 自適應擴展類

cachedAdaptiveClass= com.alibaba.dubbo.common.extension.factory.AdaptiveExtensionFactory

3 解析url

spi=com.alibaba.dubbo.common.extension.factory.SpiExtensionFactory

name=spi

line=com.alibaba.dubbo.common.extension.factory.SpiExtensionFactory

clazz=com.alibaba.dubbo.common.extension.factory.SpiExtensionFactory

extensionClasses.put(n, clazz);


AAA 2 自適應擴展類 使用該類:

com.alibaba.dubbo.common.extension.factory.AdaptiveExtensionFactory

@Adaptive? 自適應擴展類 代碼實現

public class AdaptiveExtensionFactory implements ExtensionFactory {


? ? private final List factories;


? ? public AdaptiveExtensionFactory() {

ExtensionLoader loader = ExtensionLoader.getExtensionLoader(ExtensionFactory.class);

? ? ? ? List list = new ArrayList();

? ? ? ? for (String name : loader.getSupportedExtensions()) {

? ? ? ? ? ? list.add(loader.getExtension(name));

? ? ? ? }

? ? ? ? factories = Collections.unmodifiableList(list);

? ? }

? ? public T getExtension(Class type, String name) {

? ? ? ? for (ExtensionFactory factory : factories) {

? ? ? ? ? ? T extension = factory.getExtension(type, name);

? ? ? ? ? ? if (extension != null) {

? ? ? ? ? ? ? ? return extension;

? ? ? ? ? ? }

? ? ? ? }

? ? ? ? return null;

? ? }

}

自適應擴展工廠:包含spi,spring兩個擴展工廠


BBB 其次才會繼續加載protocol:

對應的文件內容

registry=com.alibaba.dubbo.registry.integration.RegistryProtocol

dubbo=com.alibaba.dubbo.rpc.protocol.dubbo.DubboProtocol

filter=com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper

listener=com.alibaba.dubbo.rpc.protocol.ProtocolListenerWrapper

mock=com.alibaba.dubbo.rpc.support.MockProtocol

injvm=com.alibaba.dubbo.rpc.protocol.injvm.InjvmProtocol

rmi=com.alibaba.dubbo.rpc.protocol.rmi.RmiProtocol

hessian=com.alibaba.dubbo.rpc.protocol.hessian.HessianProtocol

com.alibaba.dubbo.rpc.protocol.http.HttpProtocol

com.alibaba.dubbo.rpc.protocol.webservice.WebServiceProtocol

thrift=com.alibaba.dubbo.rpc.protocol.thrift.ThriftProtocol

memcached=memcom.alibaba.dubbo.rpc.protocol.memcached.MemcachedProtocol

java.lang.ClassNotFoundException: memcom.alibaba.dubbo.rpc.protocol.memcached.MemcachedProtocol

redis=com.alibaba.dubbo.rpc.protocol.redis.RedisProtocol


其中對應的filter listener

filter=com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper

listener=com.alibaba.dubbo.rpc.protocol.ProtocolListenerWrapper

會單獨緩存到Set> cachedWrapperClasses中


異常--->放置到exceptions中


// 完全沒有Adaptive方法,則不需要生成Adaptive類


//有類型為URL的參數 或者參數中有 getUrl()方法 -- 則可以創建 adaptive class 作者拼寫錯誤為 adative


//生成具體的擴展類實例

com.alibaba.dubbo.rpc.Protocol extension = (com.alibaba.dubbo.rpc.Protocol)ExtensionLoader.getExtensionLoader(com.alibaba.dubbo.rpc.Protocol.class).getExtension(extName);


動態編譯的java代碼文件

package com.alibaba.dubbo.rpc;

import com.alibaba.dubbo.common.extension.ExtensionLoader;

public class Protocol$Adpative implements com.alibaba.dubbo.rpc.Protocol {

public void destroy() {throw new UnsupportedOperationException("method public abstract void com.alibaba.dubbo.rpc.Protocol.destroy() of interface com.alibaba.dubbo.rpc.Protocol is not adaptive method!");

}

public int getDefaultPort() {throw new UnsupportedOperationException("method public abstract int com.alibaba.dubbo.rpc.Protocol.getDefaultPort() of interface com.alibaba.dubbo.rpc.Protocol is not adaptive method!");

}

public com.alibaba.dubbo.rpc.Exporter export(com.alibaba.dubbo.rpc.Invoker arg0) throws com.alibaba.dubbo.rpc.Invoker {

if (arg0 == null) throw new IllegalArgumentException("com.alibaba.dubbo.rpc.Invoker argument == null");

if (arg0.getUrl() == null) throw new IllegalArgumentException("com.alibaba.dubbo.rpc.Invoker argument getUrl() == null");com.alibaba.dubbo.common.URL url = arg0.getUrl();

String extName = ( url.getProtocol() == null ? "dubbo" : url.getProtocol() );

if(extName == null) throw new IllegalStateException("Fail to get extension(com.alibaba.dubbo.rpc.Protocol) name from url(" + url.toString() + ") use keys([protocol])");

com.alibaba.dubbo.rpc.Protocol extension = (com.alibaba.dubbo.rpc.Protocol)ExtensionLoader.getExtensionLoader(com.alibaba.dubbo.rpc.Protocol.class).getExtension(extName);

return extension.export(arg0);

}

public com.alibaba.dubbo.rpc.Invoker refer(java.lang.Class arg0, com.alibaba.dubbo.common.URL arg1) throws java.lang.Class {

if (arg1 == null) throw new IllegalArgumentException("url == null");

com.alibaba.dubbo.common.URL url = arg1;

String extName = ( url.getProtocol() == null ? "dubbo" : url.getProtocol() );

if(extName == null) throw new IllegalStateException("Fail to get extension(com.alibaba.dubbo.rpc.Protocol) name from url(" + url.toString() + ") use keys([protocol])");

com.alibaba.dubbo.rpc.Protocol extension = (com.alibaba.dubbo.rpc.Protocol)ExtensionLoader.getExtensionLoader(com.alibaba.dubbo.rpc.Protocol.class).getExtension(extName);

return extension.refer(arg0, arg1);

}

}

最后編輯于
?著作權歸作者所有,轉載或內容合作請聯系作者
平臺聲明:文章內容(如有圖片或視頻亦包括在內)由作者上傳并發布,文章內容僅代表作者本人觀點,簡書系信息發布平臺,僅提供信息存儲服務。

推薦閱讀更多精彩內容