motan(https://github.com/weibocom/motan.git)是微博开源出来的一款轻量级RPC框架，结合Spring食用，配置简单易上手。之前搞过facebook开源的thrift框架，thrift虽然支持众多语言，但像服务注册与发现、负载均衡这些重要的功能都没有提供，自己实现的费时费力又不稳定，最总还是放弃了。
这次说说motan的启动：
先说一下Spring的BeanPostProcessor接口，该接口中定义了两个方法：
public interface BeanPostProcessor {
/**
* Apply this BeanPostProcessor to the given new bean instance <i>before</i> any bean
* initialization callbacks (like InitializingBean‘s {@code afterPropertiesSet}
* or a custom init-method). The bean will already be populated with property values.
* The returned bean instance may be a wrapper around the original.
* @param bean the new bean instance
* @param beanName the name of the bean
* @return the bean instance to use, either the original or a wrapped one;
* if {@code null}, no subsequent BeanPostProcessors will be invoked
* @throws org.springframework.beans.BeansException in case of errors
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet
*/
Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException;
/**
* Apply this BeanPostProcessor to the given new bean instance <i>after</i> any bean
* initialization callbacks (like InitializingBean‘s {@code afterPropertiesSet}
* or a custom init-method). The bean will already be populated with property values.
* The returned bean instance may be a wrapper around the original.
* <p>In case of a FactoryBean, this callback will be invoked for both the FactoryBean
* instance and the objects created by the FactoryBean (as of Spring 2.0). The
* post-processor can decide whether to apply to either the FactoryBean or created
* objects or both through corresponding {@code bean instanceof FactoryBean} checks.
* <p>This callback will also be invoked after a short-circuiting triggered by a
* {@link InstantiationAwareBeanPostProcessor#postProcessBeforeInstantiation} method,
* in contrast to all other BeanPostProcessor callbacks.
* @param bean the new bean instance
* @param beanName the name of the bean
* @return the bean instance to use, either the original or a wrapped one;
* if {@code null}, no subsequent BeanPostProcessors will be invoked
* @throws org.springframework.beans.BeansException in case of errors
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet
* @see org.springframework.beans.factory.FactoryBean
*/
Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException;
}
postProcessBeforeInitialization在实例化及依赖注入完成后、在任何初始化代码调用之前调用；postProcessAfterInitialization在初始化代码调用之后调用。motan的com.weibo.api.motan.config.springsupport.AnnotationBean类实现了BeanPostProcessor接口，并且在postProcessAfterInitialization方法中完成了rpc服务的配置与启动：
/**
* init service config and export servcice
*
* @param bean
* @param beanName
* @return
* @throws BeansException
*/
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if (!isMatchPackage(bean)) {
return bean;
}
Class<?> clazz = bean.getClass();
if (isProxyBean(bean)) {
clazz = AopUtils.getTargetClass(bean);
}
MotanService service = clazz.getAnnotation(MotanService.class);
if (service != null) {
ServiceConfigBean<Object> serviceConfig = new ServiceConfigBean<Object>();
if (void.class.equals(service.interfaceClass())) {
if (clazz.getInterfaces().length > 0) {
Class<Object> clz = (Class<Object>) clazz.getInterfaces()[0];
serviceConfig.setInterface(clz);
} else {
throw new IllegalStateException("Failed to export remote service class " + clazz.getName()
+ ", cause: The @Service undefined interfaceClass or interfaceName, and the service class unimplemented any interfaces.");
}
} else {
serviceConfig.setInterface((Class<Object>) service.interfaceClass());
}
if (beanFactory != null) {
serviceConfig.setBeanFactory(beanFactory);
if (service.basicService() != null && service.basicService().length() > 0) {
serviceConfig.setBasicService(beanFactory.getBean(service.basicService(), BasicServiceInterfaceConfig.class));
}
if (service.export() != null && service.export().length() > 0) {
serviceConfig.setExport(service.export());
}
if (service.host() != null && service.host().length() > 0) {
serviceConfig.setHost(service.host());
}
String protocolValue = null;
if (service.protocol() != null && service.protocol().length() > 0) {
protocolValue = service.protocol();
} else if (service.export() != null && service.export().length() > 0) {
protocolValue = ConfigUtil.extractProtocols(service.export());
}
if (!StringUtils.isBlank(protocolValue)) {
List<ProtocolConfig> protocolConfigs = SpringBeanUtil.getMultiBeans(beanFactory, protocolValue, SpringBeanUtil.COMMA_SPLIT_PATTERN,
ProtocolConfig.class);
serviceConfig.setProtocols(protocolConfigs);
}
// String[] methods() default {};
if (service.registry() != null && service.registry().length() > 0) {
List<RegistryConfig> registryConfigs = SpringBeanUtil.getMultiBeans(beanFactory, service.registry
(), SpringBeanUtil.COMMA_SPLIT_PATTERN, RegistryConfig.class);
serviceConfig.setRegistries(registryConfigs);
}
if (service.extConfig() != null && service.extConfig().length() > 0) {
serviceConfig.setExtConfig(beanFactory.getBean(service.extConfig(), ExtConfig.class));
}
if (service.application() != null && service.application().length() > 0) {
serviceConfig.setApplication(service.application());
}
if (service.module() != null && service.module().length() > 0) {
serviceConfig.setModule(service.module());
}
if (service.group() != null && service.group().length() > 0) {
serviceConfig.setGroup(service.group());
}
if (service.version() != null && service.version().length() > 0) {
serviceConfig.setVersion(service.version());
}
if (service.proxy() != null && service.proxy().length() > 0) {
serviceConfig.setProxy(service.proxy());
}
if (service.filter() != null && service.filter().length() > 0) {
serviceConfig.setFilter(service.filter());
}
if (service.actives() > 0) {
serviceConfig.setActives(service.actives());
}
if(service.async()) {
serviceConfig.setAsync(service.async());
}
if (service.mock() != null && service.mock().length() > 0) {
serviceConfig.setMock(service.mock());
}
// 是否共享 channel
if (service.shareChannel()) {
serviceConfig.setShareChannel(service.shareChannel());
}
// if throw exception when call failure，the default value is ture
if (service.throwException()) {
serviceConfig.setThrowException(service.throwException());
}
if(service.requestTimeout()>0) {
serviceConfig.setRequestTimeout(service.requestTimeout());
}
if (service.register()) {
serviceConfig.setRegister(service.register());
}
if (service.accessLog()) {
serviceConfig.setAccessLog("true");
}
if (service.check()) {
serviceConfig.setCheck("true");
}
if (service.usegz()) {
serviceConfig.setUsegz(service.usegz());
}
if(service.retries()>0) {
serviceConfig.setRetries(service.retries());
}
if(service.mingzSize()>0) {
serviceConfig.setMingzSize(service.mingzSize());
}
if (service.codec() != null && service.codec().length() > 0) {
serviceConfig.setCodec(service.codec());
}
try {
serviceConfig.afterPropertiesSet();
} catch (RuntimeException e) {
throw (RuntimeException) e;
} catch (Exception e) {
throw new IllegalStateException(e.getMessage(), e);
}
}
serviceConfig.setRef(bean);
serviceConfigs.add(serviceConfig);
serviceConfig.export();
}
return bean;
}
postProcessAfterInitialization先是检查当前bean是否是一个rpc服务，如果是就去加载各种配置，最后调用serviceConfig.export()，完成服务的启动。
serviceConfig.export()最终调用com.weibo.api.motan.registry.zookeeper.ZookeeperRegistry.doAvailable(URL)方法，在注册中心上添加一个节点，将该服务的地址暴露出去（motan目前支持两种注册中心，Consul和Zookeeper）。
服务并不会在启动完成之后马上注册到注册中心，motan设置了一个全局的开关，只有通过SwitcherService打开开关，服务才会进行注册
//执行该语句后，服务才会被注册到注册中心，才能对外提供服务MotanSwitcherUtil.setSwitcherValue(MotanConstants.REGISTRY_HEARTBEAT_SWITCHER, true);
时间： 2024-11-09 05:06:49