org.apache.dubbo.config.annotation

Annotation Type DubboReference

@Documented
 @Retention(value=RUNTIME)
 @Target(value={FIELD,METHOD,ANNOTATION_TYPE})
public @interface DubboReference

An annotation used for referencing a Dubbo service.

It is recommended to use @DubboReference on the @Bean method in the Java-config class, but not on the fields or setter methods to be injected.

Step 1: Register ReferenceBean in Java-config class:

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

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

Step 2: Inject ReferenceBean by @Autowired

 public class FooController {
     @Autowired
     private HelloService helloService;

     @Autowired
     private GenericService genericHelloService;
 }
 

Since:

2.7.7

See Also:

org.apache.dubbo.config.spring.reference.ReferenceBeanBuilder, org.apache.dubbo.config.spring.ReferenceBean

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
int	actives Maximum active requests allowed, default value is 0
String	application Deprecated. This attribute was deprecated, use bind application/module of spring ApplicationContext
boolean	async Whether to enable async invocation, default value is false
String	cache Specify cache implementation for service invocation, legal values include: lru, threadlocal, jcache
int	callbacks The callback instance limit peer connection
boolean	check Check if service provider is available during boot up, default value is true
String	client Client transport type, default value is "netty"
String	cluster Cluster strategy, legal values include: failover, failfast, failsafe, failback, forking you can use ClusterRules.FAIL_FAST ……
int	connections Maximum connections service provider can accept, default value is 0 - connection is shared
String	consumer Consumer associated name
String[]	filter Filters for service invocation
boolean	generic Deprecated. Do not need specify generic value, judge by injection type and interface class
String	group Service group, default value is empty string
String	id The id NOTE: The id attribute is ignored when using @DubboReference on @Bean method
boolean	init Whether eager initialize the reference bean when all properties are set, default value is true ( null as true)
boolean	injvm Deprecated. using scope="local" or scope="remote" instead
Class<?>	interfaceClass Interface class, default value is void.class
String	interfaceName Interface class name, default value is empty string
String	layer Service layer, default value is empty string
boolean	lazy Whether to make connection when the client is created, the default value is false
String[]	listener Listeners for service exporting and unexporting
String	loadbalance Load balance strategy, legal values include: random, roundrobin, leastactive you can use LoadbalanceRules.RANDOM ……
String	merger Service merger
Method[]	methods methods support
String	mock Service mock name, use interface name + Mock if not set
String	module Module associated name
String	monitor Monitor associated name
String	onconnect Callback method name when connected, default value is empty string
String	ondisconnect Callback method name when disconnected, default value is empty string
String	owner Service owner, default value is empty string
String[]	parameters Customized parameter key-value pair, for example: {key1, value1, key2, value2} or {"key1=value1", "key2=value2"}
String	protocol The communication protocol of Dubbo Service
String[]	providedBy declares which app or service this interface belongs to
String	providerNamespace assign the namespace that provider belong to
int	providerPort The service port of the provider
String	proxy How the proxy is generated, legal values include: jdk, javassist
String	reconnect Whether to reconnect if connection is lost, if not specify, reconnect is enabled by default, and the interval for retry connecting is 2000 ms
boolean	referAsync Weather the reference is refer asynchronously
String[]	registry Registry associated name
int	retries Service invocation retry times
String	scope the scope for referring/exporting a service, if it's local, it means searching in current JVM only.
boolean	sent Whether the async request has already been sent, the default value is false
String[]	services Deprecated. using providedBy()
boolean	sticky Whether to stick to the same node in the cluster, the default value is false
String	stub Service stub name, use interface name + Stub if not set
boolean	stubevent Export an stub service for event dispatch, default value is false.
String	tag Service tag name
int	timeout Timeout value for service invocation, default value is 0
boolean	unloadClusterRelated unload Cluster related in mesh mode
String	url Service target URL for direct invocation, if this is specified, then registry center takes no effect.
String	validation Whether to use JSR303 validation, legal values are: true, false
String	version Service version, default value is empty string

Element Detail

interfaceClass

public abstract Class<?> interfaceClass

Interface class, default value is void.class

Default:

void.class

interfaceName

public abstract String interfaceName

Interface class name, default value is empty string

Default:

""

version

public abstract String version

Service version, default value is empty string

Default:

""

group

public abstract String group

Service group, default value is empty string

Default:

""

url

public abstract String url

Service target URL for direct invocation, if this is specified, then registry center takes no effect.

Default:

""

client

public abstract String client

Client transport type, default value is "netty"

Default:

""

generic

@Deprecated
public abstract boolean generic

Deprecated. Do not need specify generic value, judge by injection type and interface class

Whether to enable generic invocation, default value is false

Default:

false

injvm

@Deprecated
public abstract boolean injvm

Deprecated. using scope="local" or scope="remote" instead

When enable, prefer to call local service in the same JVM if it's present, default value is true

Default:

true

check

public abstract boolean check

Check if service provider is available during boot up, default value is true

Default:

true

init

public abstract boolean init

Whether eager initialize the reference bean when all properties are set, default value is true ( null as true)

See Also:

ReferenceConfigBase.shouldInit()

Default:

true

lazy

public abstract boolean lazy

Whether to make connection when the client is created, the default value is false

Default:

false

stubevent

public abstract boolean stubevent

Export an stub service for event dispatch, default value is false.

see org.apache.dubbo.rpc.Constants#STUB_EVENT_METHODS_KEY

Default:

false

reconnect

public abstract String reconnect

Whether to reconnect if connection is lost, if not specify, reconnect is enabled by default, and the interval for retry connecting is 2000 ms

see org.apache.dubbo.remoting.Constants#DEFAULT_RECONNECT_PERIOD

Default:

""

sticky

public abstract boolean sticky

Whether to stick to the same node in the cluster, the default value is false

see Constants#DEFAULT_CLUSTER_STICKY

Default:

false

proxy

public abstract String proxy

How the proxy is generated, legal values include: jdk, javassist

Default:

""

stub

public abstract String stub

Service stub name, use interface name + Stub if not set

Default:

""

cluster

public abstract String cluster

Cluster strategy, legal values include: failover, failfast, failsafe, failback, forking you can use ClusterRules.FAIL_FAST ……

Default:

""

connections

public abstract int connections

Maximum connections service provider can accept, default value is 0 - connection is shared

Default:

-1

callbacks

public abstract int callbacks

The callback instance limit peer connection

see org.apache.dubbo.rpc.Constants#DEFAULT_CALLBACK_INSTANCES

Default:

-1

onconnect

public abstract String onconnect

Callback method name when connected, default value is empty string

Default:

""

ondisconnect

public abstract String ondisconnect

Callback method name when disconnected, default value is empty string

Default:

""

owner

public abstract String owner

Service owner, default value is empty string

Default:

""

layer

public abstract String layer

Service layer, default value is empty string

Default:

""

retries

public abstract int retries

Service invocation retry times

see Constants#DEFAULT_RETRIES

Default:

-1

loadbalance

public abstract String loadbalance

Load balance strategy, legal values include: random, roundrobin, leastactive you can use LoadbalanceRules.RANDOM ……

Default:

""

async

public abstract boolean async

Whether to enable async invocation, default value is false

Default:

false

actives

public abstract int actives

Maximum active requests allowed, default value is 0

Default:

-1

sent

public abstract boolean sent

Whether the async request has already been sent, the default value is false

Default:

false

mock

public abstract String mock

Service mock name, use interface name + Mock if not set

Default:

""

validation

public abstract String validation

Whether to use JSR303 validation, legal values are: true, false

Default:

""

timeout

public abstract int timeout

Timeout value for service invocation, default value is 0

Default:

-1

cache

public abstract String cache

Specify cache implementation for service invocation, legal values include: lru, threadlocal, jcache

Default:

""

filter

public abstract String[] filter

Filters for service invocation

see Filter

Default:

{}

listener

public abstract String[] listener

Listeners for service exporting and unexporting

see ExporterListener

Default:

{}

parameters

public abstract String[] parameters

Customized parameter key-value pair, for example: {key1, value1, key2, value2} or {"key1=value1", "key2=value2"}

Default:

{}

application

@Deprecated
public abstract String application

Deprecated. This attribute was deprecated, use bind application/module of spring ApplicationContext

Application name

Default:

""

module

public abstract String module

Module associated name

Default:

""

consumer

public abstract String consumer

Consumer associated name

Default:

""

monitor

public abstract String monitor

Monitor associated name

Default:

""

registry

public abstract String[] registry

Registry associated name

Default:

{}

protocol

public abstract String protocol

The communication protocol of Dubbo Service

Returns:

the default value is ""

Since:

2.6.6

Default:

""

tag

public abstract String tag

Service tag name

Default:

""

merger

public abstract String merger

Service merger

Default:

""

methods

public abstract Method[] methods

methods support

Default:

{}

id

public abstract String id

The id NOTE: The id attribute is ignored when using @DubboReference on @Bean method

Returns:

default value is empty

Since:

2.7.3

Default:

""

services

@Deprecated
public abstract String[] services

Deprecated. using providedBy()

Returns:

The service names that the Dubbo interface subscribed

Since:

2.7.8

See Also:

RegistryConstants.SUBSCRIBED_SERVICE_NAMES_KEY

Default:

{}

providedBy

public abstract String[] providedBy

declares which app or service this interface belongs to

See Also:

RegistryConstants.PROVIDED_BY

Default:

{}

providerPort

public abstract int providerPort

The service port of the provider

Since:

3.1.0

See Also:

AbstractReferenceConfig.providerPort

Default:

-1

providerNamespace

public abstract String providerNamespace

assign the namespace that provider belong to

Since:

3.1.1

See Also:

AbstractReferenceConfig.providerNamespace

Default:

""

scope

public abstract String scope

the scope for referring/exporting a service, if it's local, it means searching in current JVM only.

See Also:

org.apache.dubbo.rpc.Constants#SCOPE_LOCAL, org.apache.dubbo.rpc.Constants#SCOPE_REMOTE

Default:

""

referAsync

public abstract boolean referAsync

Weather the reference is refer asynchronously

Default:

false

unloadClusterRelated

public abstract boolean unloadClusterRelated

unload Cluster related in mesh mode

Since:

3.1.0

See Also:

ReferenceConfigBase.unloadClusterRelated

Default:

false