org.talend.esb.servicelocator.client.internal

Class ServiceLocatorImpl

java.lang.Object

org.talend.esb.servicelocator.client.internal.ServiceLocatorImpl

All Implemented Interfaces:

ExpiredEndpointCollector, ServiceLocator

public class ServiceLocatorImpl
extends Object
implements ServiceLocator, ExpiredEndpointCollector

This is the entry point for clients of the Service Locator. To access the Service Locator clients have to first connect to the Service Locator to get a session assigned. Once the connection is established the client will periodically send heart beats to the server to keep the session alive.

The Service Locator provides the following operations.

• An endpoint for a specific service can be registered.
• All endpoints for a specific service that were registered before by other clients can be looked up.

Nested Class Summary

Nested classes/interfaces inherited from interface org.talend.esb.servicelocator.client.ServiceLocator

ServiceLocator.PostConnectAction

Constructor Summary

Constructors

Constructor and Description
ServiceLocatorImpl()

Method Summary

Modifier and Type	Method and Description
void	addPostConnectAction(ServiceLocator.PostConnectAction postConnectAction) Specify the action to be be executed after the Service Locator has connected to the server.
void	connect() Establish a connection to the Service Locator.
protected org.apache.zookeeper.ZooKeeper	createZooKeeper(CountDownLatch connectionLatch)
void	disconnect() Disconnects from a Service Locator server.
SLEndpoint	getEndpoint(QName serviceName, String endpoint) Return the complete endpoint information for the given endpoint registered for the given service.
List<String>	getEndpointNames(QName serviceName) For the given service return all endpoints that currently registered at the Service Locator Service.
List<SLEndpoint>	getEndpoints(QName serviceName) Return the complete endpoint informations for all endpoints registered for the given service.
List<QName>	getServices() Return all services for which endpoints are registered at the Service Locator Service.
List<String>	lookup(QName serviceName) For the given service return all endpoints that are currently registered at the Service Locator.
List<String>	lookup(QName serviceName, SLPropertiesMatcher matcher) For the given service return all endpoints that are currently registered at the Service Locator and where the custom properties match the given matcher.
void	performCollection()
void	register(Endpoint epProvider) For a given service register the endpoint as defined in the given EndpointProvider.
void	register(Endpoint epProvider, boolean persistent) For a given service register the endpoint as defined in the given EndpointProvider.
void	register(QName serviceName, String endpoint) For a given service register the endpoint of a concrete provider of this service.
void	register(QName serviceName, String endpoint, boolean persistent)
void	register(QName serviceName, String endpoint, SLProperties properties) For a given service register the endpoint of a concrete provider of this service.
void	register(QName serviceName, String endpoint, SLProperties properties, boolean persistent)
void	removeEndpoint(QName serviceName, String endpoint) Remove the given endpoint from the list of endpoints of the given service.
void	removePostConnectAction(ServiceLocator.PostConnectAction postConnectAction) Remove the action to be be executed after the Service Locator has connected to the server.
void	setBackend(ServiceLocatorBackend backend)
void	setConnectionTimeout(int timeout) Specify the time this client waits for a connection to get established.
void	setEndpointCollectionEnable(Boolean endpointCollectionDisable)
void	setEndpointCollectionInterval(Integer endpointCollectionInterval)
void	setEndpointTransformer(EndpointTransformer endpointTransformer)
void	setLocatorEndpoints(String endpoints) Specify the endpoints of all the instances belonging to the service locator ensemble this object might potentially be talking to when connecting.
void	setName(String name)
void	setPassword(String passWord)
void	setSessionTimeout(int timeout) Specify the time out of the session established at the server.
void	startScheduledCollection()
void	stopScheduledCollection()
void	unregister(Endpoint epProvider) For a given service unregister a previously registered endpoint.
void	unregister(QName serviceName, String endpoint) For a given service unregister a previously registered endpoint.
void	updateTimetolive(QName serviceName, String endpoint, int timetolive) Updates the time-to-live (ttl) for specified endpoint.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ServiceLocatorImpl

public ServiceLocatorImpl()

Method Detail

connect

public void connect()
             throws InterruptedException,
                    ServiceLocatorException

Establish a connection to the Service Locator. After successful connection the specified ServiceLocator.PostConnectAction is run. If the session to the server expires because the server could not be reached within the specified time, a reconnect is automatically executed as soon as the server can be reached again. Because after a session time out all registered endpoints are removed it is important to specify a ServiceLocator.PostConnectAction that re-registers all endpoints.

Specified by:

connect in interface ServiceLocator

Throws:

InterruptedException - the current Thread was interrupted when waiting for a successful connection to the ServiceLocator

ServiceLocatorException - the connect operation failed

disconnect

public void disconnect()
                throws InterruptedException,
                       ServiceLocatorException

Disconnects from a Service Locator server. All endpoints that were registered before are removed from the server. To be able to communicate with a Service Locator server again the client has to connect again.

Specified by:

disconnect in interface ServiceLocator

Throws:

InterruptedException - the current Thread was interrupted when waiting for the disconnect to happen

ServiceLocatorException

register

public void register(QName serviceName,
                     String endpoint)
              throws ServiceLocatorException,
                     InterruptedException

For a given service register the endpoint of a concrete provider of this service. The endpoint is marked as live as long as this client is connected and the session on the server is valid.

The endpoint is categorized as being a SOAP / HTTP endpoint.

Specified by:

register in interface ServiceLocator

Parameters:

serviceName - the name of the service the endpoint is registered for, must not be null

endpoint - the endpoint to register, must not be null

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

register

public void register(QName serviceName,
                     String endpoint,
                     boolean persistent)
              throws ServiceLocatorException,
                     InterruptedException

Specified by:

register in interface ServiceLocator

Throws:

ServiceLocatorException

InterruptedException

register

public void register(QName serviceName,
                     String endpoint,
                     SLProperties properties)
              throws ServiceLocatorException,
                     InterruptedException

For a given service register the endpoint of a concrete provider of this service. The endpoint is marked as live as long as this client is connected and the session on the server is valid. In addition a set of custom properties is defined for the endpoint. They may be used as additional selection criteria during the lookup.

Specified by:

register in interface ServiceLocator

Parameters:

serviceName - the name of the service the endpoint is registered for, must not be null

endpoint - the endpoint to register, must not be null

properties - custom properties of the endpoint that can be used as additional selection criteria when doing a lookup.

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

register

public void register(QName serviceName,
                     String endpoint,
                     SLProperties properties,
                     boolean persistent)
              throws ServiceLocatorException,
                     InterruptedException

Specified by:

register in interface ServiceLocator

Throws:

ServiceLocatorException

InterruptedException

register

public void register(Endpoint epProvider)
              throws ServiceLocatorException,
                     InterruptedException

For a given service register the endpoint as defined in the given EndpointProvider. The endpoint is marked as live as long as this client is connected and the session on the server is valid.

Specified by:

register in interface ServiceLocator

Parameters:

epProvider - provides all the necessary information to register an endpoint like name of the service for which to register the endpoint, the endpoint URL, must not be null.

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

register

public void register(Endpoint epProvider,
                     boolean persistent)
              throws ServiceLocatorException,
                     InterruptedException

Description copied from interface: ServiceLocator

For a given service register the endpoint as defined in the given EndpointProvider. If the given persistent flag is not set the endpoint is marked as live as long as this client is connected and the session on the server is valid. Otherwise it is marked live independent of the sesion state.

Specified by:

register in interface ServiceLocator

Parameters:

epProvider - provides all the necessary information to register an endpoint like name of the service for which to register the endpoint, the endpoint URL, must not be null.

persistent - iff true the endpoint is marked live until it is explicitly unregistered.

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

unregister

public void unregister(Endpoint epProvider)
                throws ServiceLocatorException,
                       InterruptedException

Description copied from interface: ServiceLocator

For a given service unregister a previously registered endpoint.

Specified by:

unregister in interface ServiceLocator

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

unregister

public void unregister(QName serviceName,
                       String endpoint)
                throws ServiceLocatorException,
                       InterruptedException

For a given service unregister a previously registered endpoint.

Specified by:

unregister in interface ServiceLocator

Parameters:

serviceName - the name of the service the endpoint is unregistered for, must not be null

endpoint - the endpoint to unregister, must not be null

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

updateTimetolive

public void updateTimetolive(QName serviceName,
                             String endpoint,
                             int timetolive)
                      throws ServiceLocatorException,
                             InterruptedException

Description copied from interface: ServiceLocator

Updates the time-to-live (ttl) for specified endpoint. If the endpoint did not have ttl before then this method sets it up.

Specified by:

updateTimetolive in interface ServiceLocator

Parameters:

serviceName - name of the service the endpoint belongs to

endpoint - name of the endpoint

timetolive - period of time (in seconds) when this endpoint is considered "alive"

Throws:

ServiceLocatorException - thrown if a problem happened. For example if the endpoint does not exist, if given time-to-live is negative or zero, etc.

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

removeEndpoint

public void removeEndpoint(QName serviceName,
                           String endpoint)
                    throws ServiceLocatorException,
                           InterruptedException

Remove the given endpoint from the list of endpoints of the given service. When calling getEndpoint(serviceName) the given endpoint will not be contained in the returned list. In case no service with the given name exists or the given endpoint is not registered with the service the state of the Service Locator remians unchanged.

Specified by:

removeEndpoint in interface ServiceLocator

Parameters:

serviceName - the name of the service the endpoint is removed from, must not be null

endpoint - the endpoint to remove, must not be null

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

getServices

public List<QName> getServices()
                        throws InterruptedException,
                               ServiceLocatorException

Return all services for which endpoints are registered at the Service Locator Service.

Specified by:

getServices in interface ServiceLocator

Returns:

a possibly empty list of services

Throws:

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

ServiceLocatorException - the server returned an error

getEndpoints

public List<SLEndpoint> getEndpoints(QName serviceName)
                              throws ServiceLocatorException,
                                     InterruptedException

Return the complete endpoint informations for all endpoints registered for the given service.

Specified by:

getEndpoints in interface ServiceLocator

Parameters:

serviceName - the name of the service for which the endpoints ares registered, must not be null

Returns:

the list of end point informations, may be empty if no the endpoints are registered for the service.

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

getEndpoint

public SLEndpoint getEndpoint(QName serviceName,
                              String endpoint)
                       throws ServiceLocatorException,
                              InterruptedException

Return the complete endpoint information for the given endpoint registered for the given service.

Specified by:

getEndpoint in interface ServiceLocator

Parameters:

serviceName - the name of the service for which the endpoint is registered, must not be null

endpoint - the endpoint for which to return the information, must not be null

Returns:

the end point information, may be null if the endpoint was not registered before

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

getEndpointNames

public List<String> getEndpointNames(QName serviceName)
                              throws ServiceLocatorException,
                                     InterruptedException

For the given service return all endpoints that currently registered at the Service Locator Service.

Specified by:

getEndpointNames in interface ServiceLocator

Parameters:

serviceName - the name of the service for which to get the endpoints, must not be null

Returns:

a possibly empty list of endpoints

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

lookup

public List<String> lookup(QName serviceName)
                    throws ServiceLocatorException,
                           InterruptedException

For the given service return all endpoints that are currently registered at the Service Locator.

Specified by:

lookup in interface ServiceLocator

Parameters:

serviceName - the name of the service for which to get the endpoints, must not be null

Returns:

a possibly empty list of endpoints

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

lookup

public List<String> lookup(QName serviceName,
                           SLPropertiesMatcher matcher)
                    throws ServiceLocatorException,
                           InterruptedException

For the given service return all endpoints that are currently registered at the Service Locator and where the custom properties match the given matcher.

Specified by:

lookup in interface ServiceLocator

Parameters:

serviceName - the name of the service for which to get the endpoints, must not be null

matcher - custom properties of the endpoints returned match the criterias specified by this matcher

Returns:

a possibly empty list of endpoints

Throws:

ServiceLocatorException - the server returned an error

InterruptedException - the current Thread was interrupted when waiting for a response of the ServiceLocator

setLocatorEndpoints

public void setLocatorEndpoints(String endpoints)

Specify the endpoints of all the instances belonging to the service locator ensemble this object might potentially be talking to when connecting. The object will one by one pick an endpoint (the order is non-deterministic) to connect to the service locator until a connection is established.

Parameters:

endpoints - comma separated list of endpoints,each corresponding to a service locator instance. Each endpoint is specified as a host:port pair. At least one endpoint must be specified. Valid exmaples are: "127.0.0.1:2181" or "sl1.example.com:3210, sl2.example.com:3210, sl3.example.com:3210"

setSessionTimeout

public void setSessionTimeout(int timeout)

Specify the time out of the session established at the server. The session is kept alive by requests sent by this client object. If the session is idle for a period of time that would timeout the session, the client will send a PING request to keep the session alive.

Parameters:

timeout - timeout in milliseconds, must be greater than zero and less than 60000.

setConnectionTimeout

public void setConnectionTimeout(int timeout)

Specify the time this client waits for a connection to get established.

Parameters:

timeout - timeout in milliseconds, must be greater than zero

setName

public void setName(String name)

setPassword

public void setPassword(String passWord)

setEndpointTransformer

public void setEndpointTransformer(EndpointTransformer endpointTransformer)

setEndpointCollectionEnable

public void setEndpointCollectionEnable(Boolean endpointCollectionDisable)

setEndpointCollectionInterval

public void setEndpointCollectionInterval(Integer endpointCollectionInterval)

addPostConnectAction

public void addPostConnectAction(ServiceLocator.PostConnectAction postConnectAction)

Specify the action to be be executed after the Service Locator has connected to the server.

Specified by:

addPostConnectAction in interface ServiceLocator

Parameters:

postConnectAction - the action to be executed, must not be null.

removePostConnectAction

public void removePostConnectAction(ServiceLocator.PostConnectAction postConnectAction)

Remove the action to be be executed after the Service Locator has connected to the server.

Specified by:

removePostConnectAction in interface ServiceLocator

Parameters:

postConnectAction - the action to be executed, must not be null.

setBackend

public void setBackend(ServiceLocatorBackend backend)

createZooKeeper

protected org.apache.zookeeper.ZooKeeper createZooKeeper(CountDownLatch connectionLatch)
                                                  throws ServiceLocatorException

Throws:

ServiceLocatorException

startScheduledCollection

public void startScheduledCollection()

Specified by:

startScheduledCollection in interface ExpiredEndpointCollector

stopScheduledCollection

public void stopScheduledCollection()

Specified by:

stopScheduledCollection in interface ExpiredEndpointCollector

performCollection

public void performCollection()

Specified by:

performCollection in interface ExpiredEndpointCollector