AbstractServiceDiscovery (Apache Dubbo 3.1.1 API)

java.lang.Object
- org.apache.dubbo.registry.client.AbstractServiceDiscovery

All Implemented Interfaces:

Comparable<Prioritized>, Prioritized, ServiceDiscovery, RegistryService

Direct Known Subclasses:

NopServiceDiscovery, ReflectionBasedServiceDiscovery
```
public abstract class AbstractServiceDiscovery
extends Object
implements ServiceDiscovery
```
Each service discovery is bond to one application.

Field Summary
- Fields inherited from interface org.apache.dubbo.common.lang.Prioritized
  COMPARATOR, MAX_PRIORITY, MIN_PRIORITY, NORMAL_PRIORITY

Constructor Summary

Constructors
Constructor and Description
`AbstractServiceDiscovery(ApplicationModel applicationModel, URL registryURL)`
`AbstractServiceDiscovery(String serviceName, URL registryURL)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`destroy()` Destroy the `ServiceDiscovery`
`ServiceInstance`	`getLocalInstance()`
`MetadataInfo`	`getLocalMetadata()`
`MetadataInfo`	`getRemoteMetadata(String revision)`
`MetadataInfo`	`getRemoteMetadata(String revision, List<ServiceInstance> instances)`
`URL`	`getUrl()`
`boolean`	`isDestroy()`
`List<URL>`	`lookup(URL url)` Query the registered data that matches the conditions.
`void`	`register()`
`void`	`register(URL url)` Register data, such as : provider service, consumer address, route rule, override rule and other data.
`void`	`subscribe(URL url, NotifyListener listener)` Subscribe to eligible registered data and automatically push when the registered data is changed.
`void`	`unregister()`
`void`	`unregister(URL url)` Unregister
`void`	`unsubscribe(URL url, NotifyListener listener)` Unsubscribe
`void`	`update()` Update assumes that DefaultServiceInstance and its attributes will never get updated once created.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.dubbo.registry.client.ServiceDiscovery
addServiceInstancesChangedListener, createListener, getDelay, getInstances, getServices, removeServiceInstancesChangedListener, toString

Methods inherited from interface org.apache.dubbo.common.lang.Prioritized
compareTo, getPriority

- Constructor Detail
  - AbstractServiceDiscovery
```
public AbstractServiceDiscovery(ApplicationModel applicationModel,
                                URL registryURL)
```
  - AbstractServiceDiscovery
```
public AbstractServiceDiscovery(String serviceName,
                                URL registryURL)
```
- Method Detail
  - register
```
public void register()
              throws RuntimeException
```
    Specified by:
    
    register in interface ServiceDiscovery
    
    Throws:
    
    RuntimeException
  - update
```
public void update()
            throws RuntimeException
```
    Update assumes that DefaultServiceInstance and its attributes will never get updated once created. Checking hasExportedServices() before registration guarantees that at least one service is ready for creating the instance.
    
    Specified by:
    
    update in interface ServiceDiscovery
    
    Throws:
    
    RuntimeException
  - unregister
```
public void unregister()
                throws RuntimeException
```
    Specified by:
    
    unregister in interface ServiceDiscovery
    
    Throws:
    
    RuntimeException
  - getLocalInstance
```
public final ServiceInstance getLocalInstance()
```
    Specified by:
    
    getLocalInstance in interface ServiceDiscovery
  - getLocalMetadata
```
public MetadataInfo getLocalMetadata()
```
    Specified by:
    
    getLocalMetadata in interface ServiceDiscovery
  - getRemoteMetadata
```
public MetadataInfo getRemoteMetadata(String revision,
                                      List<ServiceInstance> instances)
```
    Specified by:
    
    getRemoteMetadata in interface ServiceDiscovery
  - getRemoteMetadata
```
public MetadataInfo getRemoteMetadata(String revision)
```
    Specified by:
    
    getRemoteMetadata in interface ServiceDiscovery
  - destroy
```
public final void destroy()
                   throws Exception
```
    Description copied from interface: ServiceDiscovery
    
    Destroy the ServiceDiscovery
    
    Specified by:
    
    destroy in interface ServiceDiscovery
    
    Throws:
    
    Exception - If met with error
  - isDestroy
```
public final boolean isDestroy()
```
    Specified by:
    
    isDestroy in interface ServiceDiscovery
  - register
```
public void register(URL url)
```
    Description copied from interface: RegistryService
    
    Register data, such as : provider service, consumer address, route rule, override rule and other data.
    Registering is required to support the contract:
    1. When the URL sets the check=false parameter. When the registration fails, the exception is not thrown and retried in the background. Otherwise, the exception will be thrown.
    2. When URL sets the dynamic=false parameter, it needs to be stored persistently, otherwise, it should be deleted automatically when the registrant has an abnormal exit.
    3. When the URL sets category=routers, it means classified storage, the default category is providers, and the data can be notified by the classified section.
    4. When the registry is restarted, network jitter, data can not be lost, including automatically deleting data from the broken line.
    5. Allow URLs which have the same URL but different parameters to coexist,they can't cover each other.
    
    Specified by:
    
    register in interface RegistryService
    
    Parameters:
    
    url - Registration information , is not allowed to be empty, e.g: dubbo://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin
  - unregister
```
public void unregister(URL url)
```
    Description copied from interface: RegistryService
    
    Unregister
    Unregistering is required to support the contract:
    1. If it is the persistent stored data of dynamic=false, the registration data can not be found, then the IllegalStateException is thrown, otherwise it is ignored.
    2. Unregister according to the full url match.
    
    Specified by:
    
    unregister in interface RegistryService
    
    Parameters:
    
    url - Registration information , is not allowed to be empty, e.g: dubbo://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin
  - subscribe
```
public void subscribe(URL url,
                      NotifyListener listener)
```
    Description copied from interface: RegistryService
    
    Subscribe to eligible registered data and automatically push when the registered data is changed.
    Subscribing need to support contracts:
    1. When the URL sets the check=false parameter. When the registration fails, the exception is not thrown and retried in the background.
    2. When URL sets category=routers, it only notifies the specified classification data. Multiple classifications are separated by commas, and allows asterisk to match, which indicates that all categorical data are subscribed.
    3. Allow interface, group, version, and classifier as a conditional query, e.g.: interface=org.apache.dubbo.foo.BarService&version=1.0.0
    4. And the query conditions allow the asterisk to be matched, subscribe to all versions of all the packets of all interfaces, e.g. :interface=*&group=*&version=*&classifier=*
    5. When the registry is restarted and network jitter, it is necessary to automatically restore the subscription request.
    6. Allow URLs which have the same URL but different parameters to coexist,they can't cover each other.
    7. The subscription process must be blocked, when the first notice is finished and then returned.
    
    Specified by:
    
    subscribe in interface RegistryService
    
    Parameters:
    
    url - Subscription condition, not allowed to be empty, e.g. consumer://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin
    
    listener - A listener of the change event, not allowed to be empty
  - unsubscribe
```
public void unsubscribe(URL url,
                        NotifyListener listener)
```
    Description copied from interface: RegistryService
    
    Unsubscribe
    Unsubscribing is required to support the contract:
    1. If you don't subscribe, ignore it directly.
    2. Unsubscribe by full URL match.
    
    Specified by:
    
    unsubscribe in interface RegistryService
    
    Parameters:
    
    url - Subscription condition, not allowed to be empty, e.g. consumer://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin
    
    listener - A listener of the change event, not allowed to be empty
  - lookup
```
public List<URL> lookup(URL url)
```
    Description copied from interface: RegistryService
    
    Query the registered data that matches the conditions. Corresponding to the push mode of the subscription, this is the pull mode and returns only one result.
    
    Specified by:
    
    lookup in interface RegistryService
    
    Parameters:
    
    url - Query condition, is not allowed to be empty, e.g. consumer://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin
    
    Returns:
    
    The registered information list, which may be empty, the meaning is the same as the parameters of org.apache.dubbo.registry.NotifyListener#notify(List).
    
    See Also:
    
    NotifyListener.notify(List)
  - getUrl
```
public URL getUrl()
```
    Specified by:
    
    getUrl in interface ServiceDiscovery

Class AbstractServiceDiscovery

Field Summary

Fields inherited from interface org.apache.dubbo.common.lang.Prioritized

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.dubbo.registry.client.ServiceDiscovery

Methods inherited from interface org.apache.dubbo.common.lang.Prioritized

Constructor Detail

AbstractServiceDiscovery

AbstractServiceDiscovery

Method Detail

register

update

unregister

getLocalInstance

getLocalMetadata

getRemoteMetadata

getRemoteMetadata

destroy

isDestroy

register

unregister

subscribe

unsubscribe

lookup

getUrl