ServiceDiscovery (Vert.x Stack

```
public interface ServiceDiscovery
```
Service Discovery main entry point.
The service discovery is an infrastructure that let you publish and find `services`. A `service` is a discoverable functionality. It can be qualified by its type, metadata, and location. So a `service` can be a database, a service proxy, a HTTP endpoint. It does not have to be a vert.x entity, but can be anything. Each service is described by a Record.
The service discovery implements the interactions defined in the service-oriented computing. And to some extend, also provides the dynamic service-oriented computing interaction. So, application can react to arrival and departure of services.
A service provider can:
* publish a service record * un-publish a published record * update the status of a published service (down, out of service...)
A service consumer can:
* lookup for services * bind to a selected service (it gets a ServiceReference) and use it * release the service once the consumer is done with it * listen for arrival, departure and modification of services.
Consumer would 1) lookup for service record matching their need, 2) retrieve the ServiceReference that give access to the service, 3) get a service object to access the service, 4) release the service object once done.
A state above, the central piece of information shared by the providers and consumers are records.
Providers and consumers must create their own ServiceDiscovery instance. These instances are collaborating in background (distributed structure) to keep the set of services in sync.

Author:

Clement Escoffier

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`EVENT_ID` Constant for id field of usage events.
`static String`	`EVENT_RECORD` Constant for record field of usage events.
`static String`	`EVENT_TYPE` Constant for type field of usage events.
`static String`	`EVENT_TYPE_BIND` Constant for event type `Bind`.
`static String`	`EVENT_TYPE_RELEASE` Constant for event type `Release`.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`Set<ServiceReference>`	`bindings()`
`void`	`close()` Closes the service discovery
`static ServiceDiscovery`	`create(Vertx vertx)` Creates a new instance of `ServiceDiscovery` using the default configuration.
`static ServiceDiscovery`	`create(Vertx vertx, ServiceDiscoveryOptions options)` Creates an instance of `ServiceDiscovery`.
`Future<Record>`	`getRecord(java.util.function.Function<Record,Boolean> filter)` Like `getRecord(Function, Handler)` but returns a `Future` of the asynchronous result
`Future<Record>`	`getRecord(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService)` Like `getRecords(Function, boolean, Handler)` but returns a `Future` of the asynchronous result
`void`	`getRecord(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService, Handler<AsyncResult<Record>> resultHandler)` Lookups for a single record.
`void`	`getRecord(java.util.function.Function<Record,Boolean> filter, Handler<AsyncResult<Record>> resultHandler)` Lookups for a single record.
`Future<Record>`	`getRecord(JsonObject filter)` Like `getRecord(JsonObject, Handler)` but returns a `Future` of the asynchronous result
`void`	`getRecord(JsonObject filter, Handler<AsyncResult<Record>> resultHandler)` Lookups for a single record.
`Future<Record>`	`getRecord(String id)` Like `getRecord(String, Handler)` but returns a `Future` of the asynchronous result
`void`	`getRecord(String id, Handler<AsyncResult<Record>> resultHandler)` Looks up for a single record by its registration `id`.
`Future<List<Record>>`	`getRecords(java.util.function.Function<Record,Boolean> filter)` Like `getRecords(Function, Handler)` but returns a `Future` of the asynchronous result
`Future<List<Record>>`	`getRecords(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService)` Like `getRecords(Function, boolean, Handler)` but returns a `Future` of the asynchronous result
`void`	`getRecords(java.util.function.Function<Record,Boolean> filter, boolean includeOutOfService, Handler<AsyncResult<List<Record>>> resultHandler)` Lookups for a set of records.
`void`	`getRecords(java.util.function.Function<Record,Boolean> filter, Handler<AsyncResult<List<Record>>> resultHandler)` Lookups for a set of records.
`Future<List<Record>>`	`getRecords(JsonObject filter)` Like `getRecords(JsonObject, Handler)` but returns a `Future` of the asynchronous result
`void`	`getRecords(JsonObject filter, Handler<AsyncResult<List<Record>>> resultHandler)` Lookups for a set of records.
`ServiceReference`	`getReference(Record record)` Gets a service reference from the given record.
`ServiceReference`	`getReferenceWithConfiguration(Record record, JsonObject configuration)` Gets a service reference from the given record, the reference is configured with the given json object.
`ServiceDiscoveryOptions`	`options()`
`Future<Record>`	`publish(Record record)` Like `publish(Record, Handler)` but returns a `Future` of the asynchronous result
`void`	`publish(Record record, Handler<AsyncResult<Record>> resultHandler)` Publishes a record.
`Future<Void>`	`registerServiceExporter(ServiceExporter exporter, JsonObject configuration)` Like `registerServiceExporter(ServiceExporter, JsonObject, Handler)` but returns a `Future` of the asynchronous result
`ServiceDiscovery`	`registerServiceExporter(ServiceExporter exporter, JsonObject configuration, Handler<AsyncResult<Void>> completionHandler)` Registers a discovery bridge.
`Future<Void>`	`registerServiceImporter(ServiceImporter importer, JsonObject configuration)` Like `registerServiceImporter(ServiceImporter, JsonObject, Handler)` but returns a `Future` of the asynchronous result
`ServiceDiscovery`	`registerServiceImporter(ServiceImporter importer, JsonObject configuration, Handler<AsyncResult<Void>> completionHandler)` Registers a discovery service importer.
`boolean`	`release(ServiceReference reference)` Releases the service reference.
`static void`	`releaseServiceObject(ServiceDiscovery discovery, Object svcObject)` Release the service object retrieved using `get` methods from the service type interface.
`Future<Void>`	`unpublish(String id)` Like `unpublish(String, Handler)` but returns a `Future` of the asynchronous result
`void`	`unpublish(String id, Handler<AsyncResult<Void>> resultHandler)` Un-publishes a record.
`Future<Record>`	`update(Record record)` Like `update(Record, Handler)` but returns a `Future` of the asynchronous result
`void`	`update(Record record, Handler<AsyncResult<Record>> resultHandler)` Updates the given record.

- Field Detail
  - EVENT_TYPE
```
static final String EVENT_TYPE
```
    Constant for type field of usage events.
    
    See Also:
    
    EVENT_TYPE_BIND, EVENT_TYPE_RELEASE, Constant Field Values
  - EVENT_TYPE_BIND
```
static final String EVENT_TYPE_BIND
```
    Constant for event type `Bind`.
    
    See Also:
    
    EVENT_TYPE, Constant Field Values
  - EVENT_TYPE_RELEASE
```
static final String EVENT_TYPE_RELEASE
```
    Constant for event type `Release`.
    
    See Also:
    
    EVENT_TYPE, Constant Field Values
  - EVENT_RECORD
```
static final String EVENT_RECORD
```
    Constant for record field of usage events.
    
    See Also:
    
    Constant Field Values
  - EVENT_ID
```
static final String EVENT_ID
```
    Constant for id field of usage events.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - create
```
static ServiceDiscovery create(Vertx vertx,
                               ServiceDiscoveryOptions options)
```
    Creates an instance of ServiceDiscovery.
    
    Parameters:
    
    vertx - the vert.x instance
    
    options - the discovery options
    
    Returns:
    
    the created service discovery instance.
  - create
```
static ServiceDiscovery create(Vertx vertx)
```
    Creates a new instance of ServiceDiscovery using the default configuration.
    
    Parameters:
    
    vertx - the vert.x instance
    
    Returns:
    
    the created instance
  - getReference
```
ServiceReference getReference(Record record)
```
    Gets a service reference from the given record.
    
    Parameters:
    
    record - the chosen record
    
    Returns:
    
    the service reference, that allows retrieving the service object. Once called the service reference is cached, and need to be released.
  - getReferenceWithConfiguration
```
ServiceReference getReferenceWithConfiguration(Record record,
                                               JsonObject configuration)
```
    Gets a service reference from the given record, the reference is configured with the given json object.
    
    Parameters:
    
    record - the chosen record
    
    configuration - the configuration
    
    Returns:
    
    the service reference, that allows retrieving the service object. Once called the service reference is cached, and need to be released.
  - release
```
boolean release(ServiceReference reference)
```
    Releases the service reference.
    
    Parameters:
    
    reference - the reference to release, must not be null
    
    Returns:
    
    whether or not the reference has been released.
  - registerServiceImporter
```
Future<Void> registerServiceImporter(ServiceImporter importer,
                                     JsonObject configuration)
```
    Like registerServiceImporter(ServiceImporter, JsonObject, Handler) but returns a Future of the asynchronous result
  - registerServiceImporter
```
ServiceDiscovery registerServiceImporter(ServiceImporter importer,
                                         JsonObject configuration,
                                         Handler<AsyncResult<Void>> completionHandler)
```
    Registers a discovery service importer. Importers let you integrate other discovery technologies in this service discovery.
    
    Parameters:
    
    importer - the service importer
    
    configuration - the optional configuration
    
    completionHandler - handler call when the importer has finished its initialization and initial imports
    
    Returns:
    
    the current ServiceDiscovery
  - registerServiceExporter
```
Future<Void> registerServiceExporter(ServiceExporter exporter,
                                     JsonObject configuration)
```
    Like registerServiceExporter(ServiceExporter, JsonObject, Handler) but returns a Future of the asynchronous result
  - registerServiceExporter
```
ServiceDiscovery registerServiceExporter(ServiceExporter exporter,
                                         JsonObject configuration,
                                         Handler<AsyncResult<Void>> completionHandler)
```
    Registers a discovery bridge. Exporters let you integrate other discovery technologies in this service discovery.
    
    Parameters:
    
    exporter - the service exporter
    
    configuration - the optional configuration
    
    completionHandler - handler notified when the exporter has been correctly initialized.
    
    Returns:
    
    the current ServiceDiscovery
  - close
```
void close()
```
    Closes the service discovery
  - publish
```
void publish(Record record,
             Handler<AsyncResult<Record>> resultHandler)
```
    Publishes a record.
    
    Parameters:
    
    record - the record
    
    resultHandler - handler called when the operation has completed (successfully or not). In case of success, the passed record has a registration id required to modify and un-register the service.
  - publish
```
Future<Record> publish(Record record)
```
    Like publish(Record, Handler) but returns a Future of the asynchronous result
  - unpublish
```
void unpublish(String id,
               Handler<AsyncResult<Void>> resultHandler)
```
    Un-publishes a record.
    
    Parameters:
    
    id - the registration id
    
    resultHandler - handler called when the operation has completed (successfully or not).
  - unpublish
```
Future<Void> unpublish(String id)
```
    Like unpublish(String, Handler) but returns a Future of the asynchronous result
  - getRecord
```
void getRecord(JsonObject filter,
               Handler<AsyncResult<Record>> resultHandler)
```
    Lookups for a single record.
    Filters are expressed using a Json object. Each entry of the given filter will be checked against the record. All entry must match exactly the record. The entry can use the special "*" value to denotes a requirement on the key, but not on the value.
    Let's take some example:
```
   { "name" = "a" } => matches records with name set fo "a"
   { "color" = "*" } => matches records with "color" set
   { "color" = "red" } => only matches records with "color" set to "red"
   { "color" = "red", "name" = "a"} => only matches records with name set to "a", and color set to "red"
 
```
    If the filter is not set (null or empty), it accepts all records.
    This method returns the first matching record.
    Parameters:
    
    filter - the filter.
    
    resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeeds, but the async result has no result (null).
  - getRecord
```
Future<Record> getRecord(JsonObject filter)
```
    Like getRecord(JsonObject, Handler) but returns a Future of the asynchronous result
  - getRecord
```
void getRecord(String id,
               Handler<AsyncResult<Record>> resultHandler)
```
    Looks up for a single record by its registration id.
    When there are no matching record, the operation succeeds, but the async result has no result (null).
    
    Parameters:
    
    id - the registration id
    
    resultHandler - handler called when the lookup has been completed
    
    See Also:
    
    Record.getRegistration()
  - getRecord
```
Future<Record> getRecord(String id)
```
    Like getRecord(String, Handler) but returns a Future of the asynchronous result
  - getRecord
```
void getRecord(java.util.function.Function<Record,Boolean> filter,
               Handler<AsyncResult<Record>> resultHandler)
```
    Lookups for a single record.
    The filter is a Function taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.
    This method only looks for records with a UP status.
    
    Parameters:
    
    filter - the filter, must not be null. To return all records, use a function accepting all records
    
    resultHandler - the result handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has no result.
  - getRecord
```
Future<Record> getRecord(java.util.function.Function<Record,Boolean> filter)
```
    Like getRecord(Function, Handler) but returns a Future of the asynchronous result
  - getRecord
```
void getRecord(java.util.function.Function<Record,Boolean> filter,
               boolean includeOutOfService,
               Handler<AsyncResult<Record>> resultHandler)
```
    Lookups for a single record.
    The filter is a Function taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.
    Unlike getRecord(Function, Handler), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.
    
    Parameters:
    
    filter - the filter, must not be null. To return all records, use a function accepting all records
    
    includeOutOfService - whether or not the filter accepts OUT OF SERVICE records
    
    resultHandler - the result handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has no result.
  - getRecord
```
Future<Record> getRecord(java.util.function.Function<Record,Boolean> filter,
                         boolean includeOutOfService)
```
    Like getRecords(Function, boolean, Handler) but returns a Future of the asynchronous result
  - getRecords
```
void getRecords(JsonObject filter,
                Handler<AsyncResult<List<Record>>> resultHandler)
```
    Lookups for a set of records. Unlike getRecord(JsonObject, Handler), this method returns all matching records.
    
    Parameters:
    
    filter - the filter - see getRecord(JsonObject, Handler)
    
    resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has an empty list as result.
  - getRecords
```
Future<List<Record>> getRecords(JsonObject filter)
```
    Like getRecords(JsonObject, Handler) but returns a Future of the asynchronous result
  - getRecords
```
void getRecords(java.util.function.Function<Record,Boolean> filter,
                Handler<AsyncResult<List<Record>>> resultHandler)
```
    Lookups for a set of records. Unlike getRecord(Function, Handler), this method returns all matching records.
    The filter is a Function taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.
    This method only looks for records with a UP status.
    
    Parameters:
    
    filter - the filter, must not be null. To return all records, use a function accepting all records
    
    resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has an empty list as result.
  - getRecords
```
Future<List<Record>> getRecords(java.util.function.Function<Record,Boolean> filter)
```
    Like getRecords(Function, Handler) but returns a Future of the asynchronous result
  - getRecords
```
void getRecords(java.util.function.Function<Record,Boolean> filter,
                boolean includeOutOfService,
                Handler<AsyncResult<List<Record>>> resultHandler)
```
    Lookups for a set of records. Unlike getRecord(Function, Handler), this method returns all matching records.
    The filter is a Function taking a Record as argument and returning a boolean. You should see it as an accept method of a filter. This method return a record passing the filter.
    Unlike getRecords(Function, Handler), this method may accept records with a OUT OF SERVICE status, if the includeOutOfService parameter is set to true.
    
    Parameters:
    
    filter - the filter, must not be null. To return all records, use a function accepting all records
    
    includeOutOfService - whether or not the filter accepts OUT OF SERVICE records
    
    resultHandler - handler called when the lookup has been completed. When there are no matching record, the operation succeed, but the async result has an empty list as result.
  - getRecords
```
Future<List<Record>> getRecords(java.util.function.Function<Record,Boolean> filter,
                                boolean includeOutOfService)
```
    Like getRecords(Function, boolean, Handler) but returns a Future of the asynchronous result
  - update
```
void update(Record record,
            Handler<AsyncResult<Record>> resultHandler)
```
    Updates the given record. The record must has been published, and has it's registration id set.
    
    Parameters:
    
    record - the updated record
    
    resultHandler - handler called when the lookup has been completed.
  - update
```
Future<Record> update(Record record)
```
    Like update(Record, Handler) but returns a Future of the asynchronous result
  - bindings
```
Set<ServiceReference> bindings()
```
    Returns:
    
    the set of service references retrieved by this service discovery.
  - options
```
ServiceDiscoveryOptions options()
```
    Returns:
    
    the discovery options. Modifying the returned object would not update the discovery service configuration. This object should be considered as read-only.
  - releaseServiceObject
```
static void releaseServiceObject(ServiceDiscovery discovery,
                                 Object svcObject)
```
    Release the service object retrieved using get methods from the service type interface. It searches for the reference associated with the given object and release it.
    
    Parameters:
    
    discovery - the service discovery
    
    svcObject - the service object

Interface ServiceDiscovery

Field Summary

Method Summary

Field Detail

EVENT_TYPE

EVENT_TYPE_BIND

EVENT_TYPE_RELEASE

EVENT_RECORD

EVENT_ID

Method Detail

create

create

getReference

getReferenceWithConfiguration

release

registerServiceImporter

registerServiceImporter

registerServiceExporter

registerServiceExporter

close

publish

publish

unpublish

unpublish

getRecord

getRecord

getRecord

getRecord

getRecord

getRecord

getRecord

getRecord

getRecords

getRecords

getRecords

getRecords

getRecords

getRecords

update

update

bindings

options

releaseServiceObject