org.apache.sling.discovery.commons

Class InstancesDiff

java.lang.Object

org.apache.sling.discovery.commons.InstancesDiff

public final class InstancesDiff
extends java.lang.Object

The InstancesDiff allows to combine and filter two collections of InstanceDescription instances, an "old" collection and a "new" collection.

The comparison between InstanceDescription instances is done only on the basis of the Sling identifier. Two instances with the same Sling identifier are considered as equal.

Note: Each collection must contain only unique instances (no two instances with the same Sling identifier). Using the InstancesDiff with collections containing duplicated Sling id will throw an IllegalArgumentException.

Since:

1.0.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	InstancesDiff.InstanceCollection The InstanceCollection collection allows to filter the instances using a set of custom filter either implementing InstanceFilter or pre-defined ones.

Constructor Summary

Constructors

Constructor and Description
InstancesDiff(ClusterView oldView, ClusterView newView) Create a new InstancesDiff based on the instances from the old and new ClusterView cluster views provided.
InstancesDiff(java.util.Collection<T> oldInstances, java.util.Collection<T> newInstances) Create a new InstancesDiff based on the provided old and new Collection collections of instances.
InstancesDiff(TopologyEvent event) Create a new InstancesDiff based on the instances from the old and new TopologyView topology views contained in the TopologyEvent event provided.
InstancesDiff(TopologyView oldView, TopologyView newView) Create a new InstancesDiff based on the instances from the old and new TopologyView topology views provided.

Method Summary

Modifier and Type	Method and Description
InstancesDiff.InstanceCollection	added() Returns the InstanceCollection collection containing the InstanceDescription instances that are contained in the new collection but not in the old collection.
InstancesDiff.InstanceCollection	all(boolean retainFromNewCollection) Returns the InstanceSet set containing the InstanceDescription instances that are contained in either the old or the new collection.
InstancesDiff.InstanceCollection	removed() Returns the InstanceCollection collection containing the InstanceDescription instances that are contained in the old collection but not in the new collection.
InstancesDiff.InstanceCollection	retained(boolean retainFromNewCollection) Returns the InstanceSet collection containing the InstanceDescription instances that are contained in both the old collection and the new collection.
InstancesDiff.InstanceCollection	retained(boolean retainFromNewCollection, boolean propertyChanged) Returns the InstanceCollection collection containing the InstanceDescription instances that are contained in both the old and the new collections.

Methods inherited from class java.lang.Object

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

Constructor Detail

InstancesDiff

public InstancesDiff(TopologyEvent event)

Create a new InstancesDiff based on the instances from the old and new TopologyView topology views contained in the TopologyEvent event provided.

Parameters:

event - the non null event from which the old and new topology views are used for computing. If either of the topology views are null, then they will be substituted by an empty collection of instances.

Throws:

java.lang.IllegalArgumentException - if either of the collections contains duplicated Sling identifiers.

InstancesDiff

public InstancesDiff(TopologyView oldView,
                     TopologyView newView)

Create a new InstancesDiff based on the instances from the old and new TopologyView topology views provided.

Parameters:

oldView - the non null old topology view from which the old collection is used for computing.

newView - the non null new topology view form which the new collection is used for computing.

Throws:

java.lang.IllegalArgumentException - if either of the collections contains duplicated Sling identifiers.

InstancesDiff

public InstancesDiff(ClusterView oldView,
                     ClusterView newView)

Create a new InstancesDiff based on the instances from the old and new ClusterView cluster views provided.

Parameters:

oldView - the non null old cluster view used for computing.

newView - the non null new cluster view used for computing.

Throws:

java.lang.IllegalArgumentException - if either of the collections contains duplicated Sling identifiers.

InstancesDiff

public InstancesDiff(java.util.Collection<T> oldInstances,
                     java.util.Collection<T> newInstances)

Create a new InstancesDiff based on the provided old and new Collection collections of instances.

Type Parameters:

T - the type of instance which must extend InstanceDescription.

Parameters:

oldInstances - the non null old collection of instances used for computing.

newInstances - the non null new collection of instances used for computing.

Throws:

java.lang.IllegalArgumentException - if either of the collections contains duplicated Sling identifiers.

Method Detail

all

public InstancesDiff.InstanceCollection all(boolean retainFromNewCollection)

Returns the InstanceSet set containing the InstanceDescription instances that are contained in either the old or the new collection.

For InstanceDescription instances contained in both the old and the new collections, the method will retain those from either of the collections depending on the parameter #retainFromNewView.

Parameters:

retainFromNewCollection - true in order to retain the instances from the new collection ; false in order to retain the instances from the old collection.

Returns:

the InstanceCollection collection containing the InstanceDescription instances from both collections.

added

public InstancesDiff.InstanceCollection added()

Returns the InstanceCollection collection containing the InstanceDescription instances that are contained in the new collection but not in the old collection.

Returns:

the InstanceCollection collection containing the instances in the new topology collection but not in the old collection.

removed

public InstancesDiff.InstanceCollection removed()

Returns the InstanceCollection collection containing the InstanceDescription instances that are contained in the old collection but not in the new collection.

Returns:

the InstanceSet set containing the instances in the old collection but not in the new collection.

retained

public InstancesDiff.InstanceCollection retained(boolean retainFromNewCollection)

Returns the InstanceSet collection containing the InstanceDescription instances that are contained in both the old collection and the new collection.

The method will retain the InstanceDescription instances from either of the collections depending on the parameter #retainFromNewView.

Parameters:

retainFromNewCollection - true in order to retain the instances from the new collection ; false in order to retain the instances from the old collection.

Returns:

the InstanceCollection collection containing the InstanceDescription instances contained in both collections.

retained

public InstancesDiff.InstanceCollection retained(boolean retainFromNewCollection,
                                                 boolean propertyChanged)

Returns the InstanceCollection collection containing the InstanceDescription instances that are contained in both the old and the new collections.

The method will retain the InstanceDescription instances from either of the collections depending on the parameter #retainFromNewView.

Parameters:

retainFromNewCollection - true in order to retain the instances from the new collection ; false in order to retain the instances from the old collection.

propertyChanged - true in order to keep only the instances which properties have changed between the old and new collections ; false in order to keep only the instances which properties have not changed.

Returns:

the InstanceCollection collection containing the InstanceDescription instances contained in both views.