org.apache.dubbo.config.spring

Class ReferenceBean<T>

java.lang.Object

org.apache.dubbo.config.spring.ReferenceBean<T>

All Implemented Interfaces:

org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanClassLoaderAware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.DisposableBean, org.springframework.beans.factory.FactoryBean<T>, org.springframework.beans.factory.InitializingBean, org.springframework.context.ApplicationContextAware

public class ReferenceBean<T>
extends Object
implements org.springframework.beans.factory.FactoryBean<T>, org.springframework.context.ApplicationContextAware, org.springframework.beans.factory.BeanClassLoaderAware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.InitializingBean, org.springframework.beans.factory.DisposableBean

Spring FactoryBean for ReferenceConfig.

Step 1: Register ReferenceBean in Java-config class:

 @Configuration
 public class ReferenceConfiguration {
     @Bean
     @DubboReference(group = "demo")
     public ReferenceBean<HelloService> helloService() {
         return new ReferenceBean();
     }

     // As GenericService
     @Bean
     @DubboReference(group = "demo", interfaceClass = HelloService.class)
     public ReferenceBean<GenericService> genericHelloService() {
         return new ReferenceBean();
     }
 }
 

Or register ReferenceBean in xml:

 <dubbo:reference id="helloService" interface="org.apache.dubbo.config.spring.api.HelloService"/>
 <!-- As GenericService -->
 <dubbo:reference id="genericHelloService" interface="org.apache.dubbo.config.spring.api.HelloService" generic="true"/>
 

Step 2: Inject ReferenceBean by @Autowired

 public class FooController {
     @Autowired
     private HelloService helloService;

     @Autowired
     private GenericService genericHelloService;
 }
 

See Also:

DubboReference, ReferenceBeanBuilder

Field Summary

Fields inherited from interface org.springframework.beans.factory.FactoryBean

OBJECT_TYPE_ATTRIBUTE

Constructor Summary

Constructors

Constructor and Description
ReferenceBean()
ReferenceBean(Map<String,Object> referenceProps)

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet()
void	destroy()
String	getGroup() The group of the service
String	getId()
Class<?>	getInterfaceClass() The interface of this ReferenceBean, for injection purpose
String	getKey()
T	getObject() Create bean instance.
Class<?>	getObjectType()
org.springframework.beans.MutablePropertyValues	getPropertyValues()
ReferenceConfig	getReferenceConfig()
Map<String,Object>	getReferenceProps()
String	getServiceInterface() The interface of remote service
String	getVersion() The version of the service
boolean	isSingleton()
void	setApplicationContext(org.springframework.context.ApplicationContext applicationContext)
void	setBeanClassLoader(ClassLoader classLoader)
void	setBeanName(String name)
void	setId(String id)
void	setKeyAndReferenceConfig(String key, ReferenceConfig referenceConfig)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReferenceBean

public ReferenceBean()

ReferenceBean

public ReferenceBean(Map<String,Object> referenceProps)

Method Detail

setApplicationContext

public void setApplicationContext(org.springframework.context.ApplicationContext applicationContext)

Specified by:

setApplicationContext in interface org.springframework.context.ApplicationContextAware

setBeanClassLoader

public void setBeanClassLoader(ClassLoader classLoader)

Specified by:

setBeanClassLoader in interface org.springframework.beans.factory.BeanClassLoaderAware

setBeanName

public void setBeanName(String name)

Specified by:

setBeanName in interface org.springframework.beans.factory.BeanNameAware

getObject

public T getObject()

Create bean instance.

Why we need a lazy proxy?

When Spring searches beans by type, if Spring cannot determine the type of a factory bean, it may try to initialize it. The ReferenceBean is also a FactoryBean.
(This has already been resolved by decorating the BeanDefinition: DubboBeanDefinitionParser.configReferenceBean(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext, org.springframework.beans.factory.support.RootBeanDefinition, org.springframework.beans.factory.config.BeanDefinition))

In addition, if some ReferenceBeans are dependent on beans that are initialized very early, and dubbo config beans are not ready yet, there will be many unexpected problems if initializing the dubbo reference immediately.

When it is initialized, only a lazy proxy object will be created, and dubbo reference-related resources will not be initialized.
In this way, the influence of Spring is eliminated, and the dubbo configuration initialization is controllable.

Specified by:

getObject in interface org.springframework.beans.factory.FactoryBean<T>

See Also:

DubboConfigBeanInitializer, ReferenceBeanManager.initReferenceBean(ReferenceBean), DubboBeanDefinitionParser.configReferenceBean(org.w3c.dom.Element, org.springframework.beans.factory.xml.ParserContext, org.springframework.beans.factory.support.RootBeanDefinition, org.springframework.beans.factory.config.BeanDefinition)

getObjectType

public Class<?> getObjectType()

Specified by:

getObjectType in interface org.springframework.beans.factory.FactoryBean<T>

isSingleton

@Parameter(excluded=true)
public boolean isSingleton()

Specified by:

isSingleton in interface org.springframework.beans.factory.FactoryBean<T>

afterPropertiesSet

public void afterPropertiesSet()
                        throws Exception

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

Throws:

Exception

destroy

public void destroy()

Specified by:

destroy in interface org.springframework.beans.factory.DisposableBean

getId

public String getId()

setId

public void setId(String id)

getInterfaceClass

public Class<?> getInterfaceClass()

The interface of this ReferenceBean, for injection purpose

Returns:

getServiceInterface

public String getServiceInterface()

The interface of remote service

getGroup

public String getGroup()

The group of the service

getVersion

public String getVersion()

The version of the service

getKey

public String getKey()

getReferenceProps

public Map<String,Object> getReferenceProps()

getPropertyValues

public org.springframework.beans.MutablePropertyValues getPropertyValues()

getReferenceConfig

public ReferenceConfig getReferenceConfig()

setKeyAndReferenceConfig

public void setKeyAndReferenceConfig(String key,
                                     ReferenceConfig referenceConfig)