1.基于xml schema

http://www.w3school.com.cn/schema/index.asp

dubbo的xsd在dubbo-config工程的META-INF目录下，文件名是dubbo.xsd

2.完成解析

用NamespaceHandler的子类解析命名空间元素，用BeanDefinitionParser解析映射，dubbo的解析类分别是DubboNamespaceHandler和DubboBeanDefinitionParser

3.注册schema和handler

用spring.handlers和spring.schemas完成对shemas和handler的注册

http\://dubbo.apache.org/schema/dubbo=org.apache.dubbo.config.spring.schema.DubboNamespaceHandler

http\://code.alibabatech.com/schema/dubbo=org.apache.dubbo.config.spring.schema.DubboNamespaceHandler

http\://dubbo.apache.org/schema/dubbo/dubbo.xsd=META-INF/dubbo.xsd

http\://code.alibabatech.com/schema/dubbo/dubbo.xsd=META-INF/compat/dubbo.xsd