1) Take a look at the dubbo-registry-simple.xml file in dubbo. This file is configured by dubbo's beans in spring based on the schema file defined by dubbo itself.
With the knowledge introduced in the previous section, it is easy to understand by looking at this file now.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" //dubbo定义
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">//dubbo-defined XSD file
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
<property name="location" value="classpath:dubbo.properties" />
</bean>
<dubbo:application name="${dubbo.application.name}" owner="${dubbo.application.owner}" />
<dubbo:protocol name="dubbo" port="${dubbo.protocol.port}" heartbeat="180000" />
<dubbo:service id="registryServiceConfig" interface="com.alibaba.dubbo.registry.RegistryService" ref="registryService" registry="N/A" ondisconnect="disconnect" callbacks="1000">
<dubbo:method name="subscribe"><dubbo:argument index="1" callback="true" /></dubbo:method>
<dubbo:method name="unsubscribe"><dubbo:argument index="1" callback="false" /></dubbo:method>
</dubbo:service>
<bean id="registryService" class="com.alibaba.dubbo.registry.simple.SimpleRegistryService" />
</beans>
With the above configuration files, there should be a corresponding set of schema reflections.
2) Next, let's take a look at NamespaceHandlerSupport:
In dubbo, DubboNamespaceHandler inherits NamespaceHandlerSupport:
finds its own BeanDefinitionParser according to the node name in the XSD file, and then BeanDefinitionParser completes the specific parsing work.
public class DubboNamespaceHandler extends NamespaceHandlerSupport {
static {
Version.checkDuplicate(DubboNamespaceHandler.class);
}
public void init() {
registerBeanDefinitionParser("application", new DubboBeanDefinitionParser(ApplicationConfig.class, true));
registerBeanDefinitionParser("module", new DubboBeanDefinitionParser(ModuleConfig.class, true));
registerBeanDefinitionParser("registry", new DubboBeanDefinitionParser(RegistryConfig.class, true));
registerBeanDefinitionParser("monitor", new DubboBeanDefinitionParser(MonitorConfig.class, true));
registerBeanDefinitionParser("provider", new DubboBeanDefinitionParser(ProviderConfig.class, true));
registerBeanDefinitionParser("consumer", new DubboBeanDefinitionParser(ConsumerConfig.class, true));
registerBeanDefinitionParser("protocol", new DubboBeanDefinitionParser(ProtocolConfig.class, true));
registerBeanDefinitionParser("service", new DubboBeanDefinitionParser(ServiceBean.class, true));
registerBeanDefinitionParser("reference", new DubboBeanDefinitionParser(ReferenceBean.class, false));
registerBeanDefinitionParser("annotation", new DubboBeanDefinitionParser(AnnotationBean.class, true));
}
}
For example: registerBeanDefinitionParser("application", new DubboBeanDefinitionParser(ApplicationConfig.class, true));
will find the BEAN information configured in the XSD according to the application name, and the DubboBeanDefinitionParser will complete the parsing work.
application node in XSD:
<xsd:element name="application" type="applicationType"> <xsd:annotation> <xsd:documentation><![CDATA[ The application config ]]></xsd:documentation> </xsd:annotation> </xsd:element> <xsd:complexType name="applicationType"> <xsd:attribute name="id" type="xsd:ID"> <xsd:annotation> <xsd:documentation><![CDATA[ The unique identifier for a bean. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="name" type="xsd:string" use="required"> <xsd:annotation> <xsd:documentation><![CDATA[ The application name. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="version" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ The application version. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="owner" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ The application owner name (email prefix). ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="organization" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ The organization name. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="architecture" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ The architecture. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="environment" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ The application environment, eg: dev/test/run ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="compiler" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ The java code compiler. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="logger" type="xsd:string"> <xsd:annotation> <xsd:documentation><![CDATA[ The application logger. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="registry" type="xsd:string" use="optional"> <xsd:annotation> <xsd:documentation><![CDATA[ The application registry. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="monitor" type="xsd:string" use="optional"> <xsd:annotation> <xsd:documentation><![CDATA[ The application monitor. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> <xsd:attribute name="default" type="xsd:string" use="optional"> <xsd:annotation> <xsd:documentation><![CDATA[ Is default. ]]></xsd:documentation> </xsd:annotation> </xsd:attribute> </xsd:complexType>
Corresponding bean information:
ApplicationConfig class:
// Application Name
private String name;
// module version
private String version;
// application manager
private String owner;
// organization name (BU or department)
private String organization;
// layer
private String architecture;
// Environment, such as: dev/test/run
private String environment;
// Java code compiler
private String compiler;
// log output method
private String logger;
// registry
private List<RegistryConfig> registries;
// service monitoring
private MonitorConfig monitor;
// is it default
private Boolean isDefault;
DubboBeanDefinitionParser will naturally implement the BeanDefinitionParser interface.
Writing the value configured in the XSD file to the bean (ApplicationConfig)
is the same parser for each node that dubbo parses, which is a bit debatable .
3) The following should be spring.handlers and spring.schemas.
Specify http://code.alibabatech.com/schema/dubbo/dubbo.xsd for the xsd file
defined in META-INF/spring.schemas
http\:// code.alibabatech.com/schema/dubbo/dubbo.xsd=META-INF/dubbo.xsd is defined
in META-INF/spring.handlers
http\://code.alibabatech.com/schema/dubbo=com.alibaba.dubbo .config.spring.schema.DubboNamespaceHandler
After the introduction of these two sections, you can understand more clearly, the combination of dubbo and spring!