Package org.apache.sling.discovery.commons.providers

Class DefaultInstanceDescription

java.lang.Object

org.apache.sling.discovery.commons.providers.DefaultInstanceDescription

All Implemented Interfaces:

InstanceDescription

Direct Known Subclasses:

NonLocalInstanceDescription

public class DefaultInstanceDescription
extends Object
implements InstanceDescription

Base implementation for the InstanceDescription interface.

Allows creation of the object with clusterview and/or properties null - to be set later but before usage!

Field Summary

Fields inherited from interface org.apache.sling.discovery.InstanceDescription

PROPERTY_DESCRIPTION, PROPERTY_ENDPOINTS, PROPERTY_NAME

Constructor Summary

Constructors

Constructor	Description
DefaultInstanceDescription(DefaultClusterView clusterView, boolean isLeader, boolean isOwn, String slingId, Map<String,String> properties)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)
ClusterView	getClusterView()	Returns the ClusterView of which this instance is part of.
Map<String,String>	getProperties()	Returns a Map containing all properties of this instance.
String	getProperty(String name)	Returns the value of a particular property.
String	getSlingId()	The identifier of the running Sling instance.
int	hashCode()
boolean	isLeader()	If an instance is part of a cluster, it can potentially be a leader of that cluster - this information is queried here.
boolean	isLocal()	Determines whether this InstanceDescription is representing the local instance.
void	setProperty(String key, String value)	for testing only!
String	toString()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DefaultInstanceDescription

public DefaultInstanceDescription(DefaultClusterView clusterView,
                                  boolean isLeader,
                                  boolean isOwn,
                                  String slingId,
                                  Map<String,String> properties)

Method Detail

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

getClusterView

public ClusterView getClusterView()

Description copied from interface: InstanceDescription

Returns the ClusterView of which this instance is part of.

Every instance is part of a ClusterView even if it is standalone.

Specified by:

getClusterView in interface InstanceDescription

Returns:

the ClusterView

isLeader

public boolean isLeader()

Description copied from interface: InstanceDescription

If an instance is part of a cluster, it can potentially be a leader of that cluster - this information is queried here.

If an instance is not part of a cluster, this method returns true.

Only one instance of a cluster is guaranteed to be the leader at any time. This guarantee is provided by this service. If the leader goes down, the service elects a new leader and announces it to TopologyEventListener listeners.

Specified by:

isLeader in interface InstanceDescription

Returns:

true if this instance is the - only - leader in this cluster, false if it is one of the slaves, or true if it is not at all part of a cluster

isLocal

public boolean isLocal()

Description copied from interface: InstanceDescription

Determines whether this InstanceDescription is representing the local instance.

Specified by:

isLocal in interface InstanceDescription

Returns:

whether this InstanceDescription is representing the local instance.

getSlingId

public String getSlingId()

Description copied from interface: InstanceDescription

The identifier of the running Sling instance.

Specified by:

getSlingId in interface InstanceDescription

getProperty

public String getProperty(String name)

Description copied from interface: InstanceDescription

Returns the value of a particular property.

Note that there are no hard guarantees or requirements as to how quickly a property is available once it is set on a distant instance.

Specified by:

getProperty in interface InstanceDescription

Parameters:

name - The property name

Returns:

The value of the property or null

See Also:

DiscoveryService#setProperty(String, String)

getProperties

public Map<String,String> getProperties()

Description copied from interface: InstanceDescription

Returns a Map containing all properties of this instance. This method always returns a map, it might be empty. The returned map is not modifiable.

Specified by:

getProperties in interface InstanceDescription

Returns:

a Map containing all properties of this instance

setProperty

public void setProperty(String key,
                        String value)

for testing only!