org.apache.dubbo.registry.zookeeper

Class ZookeeperServiceDiscovery

java.lang.Object

org.apache.dubbo.registry.zookeeper.ZookeeperServiceDiscovery

All Implemented Interfaces:

Comparable<Prioritized>, EventListener, Prioritized, ServiceDiscovery

public class ZookeeperServiceDiscovery
extends Object
implements ServiceDiscovery, EventListener<ServiceInstancesChangedEvent>

Zookeeper ServiceDiscovery implementation based on Apache Curator X Discovery

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
ZookeeperServiceDiscovery()

Method Summary

Modifier and Type	Method and Description
void	addServiceInstancesChangedListener(ServiceInstancesChangedListener listener) Add an instance of ServiceInstancesChangedListener for specified service
void	destroy() Destroy the ServiceDiscovery
List<ServiceInstance>	getInstances(String serviceName) Gets all service instances by the specified service name.
Page<ServiceInstance>	getInstances(String serviceName, int offset, int pageSize, boolean healthyOnly) Get the pagination of service instances by the specified service name.
Set<String>	getServices() Gets all service names
void	initialize(URL registryURL) Initializes the ServiceDiscovery
void	onEvent(ServiceInstancesChangedEvent event) Handle a Dubbo Event when it's be published
void	register(ServiceInstance serviceInstance) Registers an instance of ServiceInstance.
void	unregister(ServiceInstance serviceInstance) Unregisters an instance of ServiceInstance.
void	update(ServiceInstance serviceInstance) Updates the registered ServiceInstance.

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

dispatchServiceInstancesChangedEvent, dispatchServiceInstancesChangedEvent, dispatchServiceInstancesChangedEvent, dispatchServiceInstancesChangedEvent, getDefaultPageSize, getInstances, getInstances, toString

Methods inherited from interface org.apache.dubbo.event.EventListener

findEventType, findEventType, findEventType, getPriority

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

compareTo

Constructor Detail

ZookeeperServiceDiscovery

public ZookeeperServiceDiscovery()

Method Detail

initialize

public void initialize(URL registryURL)
                throws Exception

Description copied from interface: ServiceDiscovery

Initializes the ServiceDiscovery

Specified by:

initialize in interface ServiceDiscovery

Parameters:

registryURL - the url to connect service registry

Throws:

Exception - If met with error

destroy

public void destroy()
             throws Exception

Description copied from interface: ServiceDiscovery

Destroy the ServiceDiscovery

Specified by:

destroy in interface ServiceDiscovery

Throws:

Exception - If met with error

register

public void register(ServiceInstance serviceInstance)
              throws RuntimeException

Description copied from interface: ServiceDiscovery

Registers an instance of ServiceInstance.

Specified by:

register in interface ServiceDiscovery

Parameters:

serviceInstance - an instance of ServiceInstance to be registered

Throws:

RuntimeException - if failed

update

public void update(ServiceInstance serviceInstance)
            throws RuntimeException

Description copied from interface: ServiceDiscovery

Updates the registered ServiceInstance.

Specified by:

update in interface ServiceDiscovery

Parameters:

serviceInstance - the registered ServiceInstance

Throws:

RuntimeException - if failed

unregister

public void unregister(ServiceInstance serviceInstance)
                throws RuntimeException

Description copied from interface: ServiceDiscovery

Unregisters an instance of ServiceInstance.

Specified by:

unregister in interface ServiceDiscovery

Parameters:

serviceInstance - an instance of ServiceInstance to be deregistered

Throws:

RuntimeException - if failed

getServices

public Set<String> getServices()

Description copied from interface: ServiceDiscovery

Gets all service names

Specified by:

getServices in interface ServiceDiscovery

Returns:

non-null read-only Set

getInstances

public List<ServiceInstance> getInstances(String serviceName)
                                   throws NullPointerException

Description copied from interface: ServiceDiscovery

Gets all service instances by the specified service name.

Specified by:

getInstances in interface ServiceDiscovery

Parameters:

serviceName - the service name

Returns:

non-null List

Throws:

NullPointerException - if serviceName is null is null

getInstances

public Page<ServiceInstance> getInstances(String serviceName,
                                          int offset,
                                          int pageSize,
                                          boolean healthyOnly)

Description copied from interface: ServiceDiscovery

Get the pagination of service instances by the specified service name. If healthyOnly == true, filter healthy instances only.

Specified by:

getInstances in interface ServiceDiscovery

Parameters:

serviceName - the service name

offset - the offset of request , the number "0" indicates first page

pageSize - the number of request, the max value indicates the range is unlimited

healthyOnly - if true , filter healthy instances only

Returns:

non-null Page object

addServiceInstancesChangedListener

public void addServiceInstancesChangedListener(ServiceInstancesChangedListener listener)
                                        throws NullPointerException,
                                               IllegalArgumentException

Description copied from interface: ServiceDiscovery

Add an instance of ServiceInstancesChangedListener for specified service

Default, Current method will be invoked by the ServiceDiscoveryRegistry on the subscription, and it's mandatory to add the ServiceInstancesChangedListener argument into EventDispatcher whether the subclass implements same approach or not, thus this method is used to trigger or adapt the vendor's change notification mechanism typically, like Zookeeper Watcher, Nacos EventListener. If the registry observes the change, It's suggested that the implementation could invoke ServiceDiscovery.dispatchServiceInstancesChangedEvent(String) method or variants

Specified by:

addServiceInstancesChangedListener in interface ServiceDiscovery

Parameters:

listener - an instance of ServiceInstancesChangedListener

Throws:

NullPointerException

IllegalArgumentException

See Also:

EventPublishingServiceDiscovery, EventDispatcher

onEvent

public void onEvent(ServiceInstancesChangedEvent event)

Description copied from interface: EventListener

Handle a Dubbo Event when it's be published

Parameters:

event - a Dubbo Event