Dubbo的@Reference和@Service说明

前言

@Reference 用在消费端，表明使用的是服务端的什么服务

 @RestController
 public class RemoteUserController {

     @Reference(version = "1.0.0",check = true)
     private RemoteUserService remoteUserService;

     @RequestMapping(value="/dubbo/say/{name}")
     public String sayHello(@PathVariable("name") String name){
         //调用服务提供者的服务
         String result=remoteUserService.sayHello(name);
         return result;
     }
 }

@Service 用在服务提供者中，在类或者接口中声明。

服务提供者实现相关的服务接口，当消费端调用相关的类时，最终会调用提供者的实现方法。

@Component
@Service(version = "1.0.0",timeout = 10000,interfaceClass = RemoteUserService.class)
public class RemoteUserServiceImpl implements RemoteUserService {

    @Override
    public String sayHello(String name) {

        log.info("访问sayHello " + name);
        return "Hello " + name;
    }
}

@Reference

@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.METHOD, ElementType.ANNOTATION_TYPE})
public @interface Reference {
    /**
     * Interface class, default value is void.class
     */
    Class<?> interfaceClass() default void.class;

    /**
     * Interface class name, default value is empty string
     */
    String interfaceName() default "";

    /**
     * Service version, default value is empty string
     */
    String version() default "";

    /**
     * Service group, default value is empty string
     */
    String group() default "";

    /**
     * Service target URL for direct invocation, if this is specified, then registry center takes no effect.
　　　* 不使用注册中心，消费者和提供者直连，url="dubbo://localhost:20890"
     */
    String url() default "";

    /**
     * Client transport type, default value is "netty"
     */
    String client() default "";

    /**
     * Whether to enable generic invocation, default value is false
     */
    boolean generic() default false;

    /**
     * When enable, prefer to call local service in the same JVM if it's present, default value is true
     */
    boolean injvm() default true;

    /**
     * Check if service provider is available during boot up, default value is true
     */
    boolean check() default true;

    /**
     * Whether eager initialize the reference bean when all properties are set, default value is false
     */
    boolean init() default false;

    /**
     * Whether to make connection when the client is created, the default value is false
     */
    boolean lazy() default false;

    /**
     * Export an stub service for event dispatch, default value is false.
     *
     * @see Constants#STUB_EVENT_METHODS_KEY
     */
    boolean stubevent() default false;

    /**
     * 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 Constants#DEFAULT_RECONNECT_PERIOD
     */
    String reconnect() default "";

    /**
     * Whether to stick to the same node in the cluster, the default value is false
     *
     * @see Constants#DEFAULT_CLUSTER_STICKY
     */
    boolean sticky() default false;

    /**
     * How the proxy is generated, legal values include: jdk, javassist
     */
    String proxy() default "";

    /**
     * Service stub name, use interface name + Local if not set
     */
    String stub() default "";

    /**
     * Cluster strategy, legal values include: failover, failfast, failsafe, failback, forking
     */
    String cluster() default "";

    /**
     * Maximum connections service provider can accept, default value is 0 - connection is shared
     */
    int connections() default 0;

    /**
     * The callback instance limit peer connection
     *
     * @see Constants#DEFAULT_CALLBACK_INSTANCES
     */
    int callbacks() default 0;

    /**
     * Callback method name when connected, default value is empty string
     */
    String onconnect() default "";

    /**
     * Callback method name when disconnected, default value is empty string
     */
    String ondisconnect() default "";

    /**
     * Service owner, default value is empty string
     */
    String owner() default "";

    /**
     * Service layer, default value is empty string
     */
    String layer() default "";

    /**
     * Service invocation retry times
     *
     * @see Constants#DEFAULT_RETRIES
     */
    int retries() default 2;

    /**
     * Load balance strategy, legal values include: random, roundrobin, leastactive
     *
     * @see Constants#DEFAULT_LOADBALANCE
     */
    String loadbalance() default "";

    /**
     * Whether to enable async invocation, default value is false
     */
    boolean async() default false;

    /**
     * Maximum active requests allowed, default value is 0
     */
    int actives() default 0;

    /**
     * Whether the async request has already been sent, the default value is false
     */
    boolean sent() default false;

    /**
     * Service mock name, use interface name + Mock if not set
     */
    String mock() default "";

    /**
     * Whether to use JSR303 validation, legal values are: true, false
     */
    String validation() default "";

    /**
     * Timeout value for service invocation, default value is 0
     */
    int timeout() default 0;

    /**
     * Specify cache implementation for service invocation, legal values include: lru, threadlocal, jcache
     */
    String cache() default "";

    /**
     * Filters for service invocation
     *
     * @see Filter
     */
    String[] filter() default {};

    /**
     * Listeners for service exporting and unexporting
     *
     * @see ExporterListener
     */
    String[] listener() default {};

    /**
     * Customized parameter key-value pair, for example: {key1, value1, key2, value2}
     */
    String[] parameters() default {};

    /**
     * Application spring bean name
     */
    String application() default "";

    /**
     * Module spring bean name
     */
    String module() default "";

    /**
     * Consumer spring bean name
     */
    String consumer() default "";

    /**
     * Monitor spring bean name
     */
    String monitor() default "";

    /**
     * Registry spring bean name
     */
    String[] registry() default {};

    /**
     * Protocol spring bean names
     */
    String protocol() default "";

    /**
     * methods support
     * @return
     */
    Method[] methods() default {};
}

@Service

@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
@Inherited
public @interface Service {

    /**
     * Interface class, default value is void.class
     */
    Class<?> interfaceClass() default void.class;

    /**
     * Interface class name, default value is empty string
     */
    String interfaceName() default "";

    /**
     * Service version, default value is empty string
     */
    String version() default "";

    /**
     * Service group, default value is empty string
     */
    String group() default "";

    /**
     * Service path, default value is empty string
     */
    String path() default "";

    /**
     * Whether to export service, default value is true
     */
    boolean export() default true;

    /**
     * Service token, default value is false
     */
    String token() default "";

    /**
     * Whether the service is deprecated, default value is false
     */
    boolean deprecated() default false;

    /**
     * Whether the service is dynamic, default value is false
     */
    boolean dynamic() default false;

    /**
     * Access log for the service, default value is ""
     */
    String accesslog() default "";

    /**
     * Maximum concurrent executes for the service, default value is 0 - no limits
     */
    int executes() default 0;

    /**
     * Whether to register the service to register center, default value is true
     */
    boolean register() default true;

    /**
     * Service weight value, default value is 0
     */
    int weight() default 0;

    /**
     * Service doc, default value is ""
     */
    String document() default "";

    /**
     * Delay time for service registration, default value is 0
     */
    int delay() default 0;

    /**
     * @see Service#stub()
     * @deprecated
     */
    String local() default "";

    /**
     * Service stub name, use interface name + Local if not set
     */
    String stub() default "";

    /**
     * Cluster strategy, legal values include: failover, failfast, failsafe, failback, forking
     */
    String cluster() default "";

    /**
     * How the proxy is generated, legal values include: jdk, javassist
     */
    String proxy() default "";

    /**
     * Maximum connections service provider can accept, default value is 0 - connection is shared
     */
    int connections() default 0;

    /**
     * The callback instance limit peer connection
     *
     * @see Constants#DEFAULT_CALLBACK_INSTANCES
     */
    int callbacks() default Constants.DEFAULT_CALLBACK_INSTANCES;

    /**
     * Callback method name when connected, default value is empty string
     */
    String onconnect() default "";

    /**
     * Callback method name when disconnected, default value is empty string
     */
    String ondisconnect() default "";

    /**
     * Service owner, default value is empty string
     */
    String owner() default "";

    /**
     * Service layer, default value is empty string
     */
    String layer() default "";

    /**
     * Service invocation retry times
     *
     * @see Constants#DEFAULT_RETRIES
     */
    int retries() default Constants.DEFAULT_RETRIES;

    /**
     * Load balance strategy, legal values include: random, roundrobin, leastactive
     *
     * @see Constants#DEFAULT_LOADBALANCE
     */
    String loadbalance() default Constants.DEFAULT_LOADBALANCE;

    /**
     * Whether to enable async invocation, default value is false
     */
    boolean async() default false;

    /**
     * Maximum active requests allowed, default value is 0
     */
    int actives() default 0;

    /**
     * Whether the async request has already been sent, the default value is false
     */
    boolean sent() default false;

    /**
     * Service mock name, use interface name + Mock if not set
     */
    String mock() default "";

    /**
     * Whether to use JSR303 validation, legal values are: true, false
     */
    String validation() default "";

    /**
     * Timeout value for service invocation, default value is 0
     */
    int timeout() default 0;

    /**
     * Specify cache implementation for service invocation, legal values include: lru, threadlocal, jcache
     */
    String cache() default "";

    /**
     * Filters for service invocation
     *
     * @see Filter
     */
    String[] filter() default {};

    /**
     * Listeners for service exporting and unexporting
     *
     * @see ExporterListener
     */
    String[] listener() default {};

    /**
     * Customized parameter key-value pair, for example: {key1, value1, key2, value2}
     */
    String[] parameters() default {};

    /**
     * Application spring bean name
     */
    String application() default "";

    /**
     * Module spring bean name
     */
    String module() default "";

    /**
     * Provider spring bean name
     */
    String provider() default "";

    /**
     * Protocol spring bean names
     */
    String[] protocol() default {};

    /**
     * Monitor spring bean name
     */
    String monitor() default "";

    /**
     * Registry spring bean name
     */
    String[] registry() default {};

    /**
     * Service tag name
     */
    String tag() default "";

    /**
     * methods support
     * @return
     */
    Method[] methods() default {};
}