Package hudson

Class ExtensionList<T>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<T>

hudson.ExtensionList<T>

Type Parameters:

T - Type of the extension point. This class holds instances of the subtypes of 'T'.

All Implemented Interfaces:

Iterable<T>, Collection<T>, List<T>, OnMaster

Direct Known Subclasses:

DescriptorExtensionList

public class ExtensionList<T>
extends AbstractList<T>
implements OnMaster

Retains the known extension instances for the given type 'T'.

Extensions are loaded lazily on demand and automatically by using ExtensionFinder, but this class also provides a mechanism to provide compatibility with the older DescriptorList-based manual registration,

All ExtensionList instances should be owned by Jenkins, even though extension points can be defined by anyone on any type. Use Jenkins.getExtensionList(Class) and Jenkins.getDescriptorList(Class) to obtain the instances.

Since:

1.286

Author:

Kohsuke Kawaguchi

See Also:

• Jenkins.getExtensionList(Class)
• Jenkins.getDescriptorList(Class)

Field Summary

Fields

Modifier and Type	Field	Description
final Class<T>	extensionType
final Hudson	hudson	Deprecated. as of 1.417 Use jenkins
final Jenkins	jenkins

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ExtensionList(Hudson hudson, Class<T> extensionType)	Deprecated. as of 1.416 Use ExtensionList(Jenkins, Class)
protected	ExtensionList(Hudson hudson, Class<T> extensionType, CopyOnWriteArrayList<ExtensionComponent<T>> legacyStore)	Deprecated. as of 1.416 Use ExtensionList(Jenkins, Class, CopyOnWriteArrayList)
protected	ExtensionList(Jenkins jenkins, Class<T> extensionType)
protected	ExtensionList(Jenkins jenkins, Class<T> extensionType, CopyOnWriteArrayList<ExtensionComponent<T>> legacyStore)

Method Summary

Modifier and Type	Method	Description
void	add(int index, T element)
boolean	add(T t)	Deprecated. since 2009-02-23.
void	addListener(ExtensionListListener listener)	Add a listener to the extension list.
static void	clearLegacyInstances()	Exposed for the test harness to clear all legacy extension instances.
static <T> ExtensionList<T>	create(Hudson hudson, Class<T> type)	Deprecated. as of 1.416 Use create(Jenkins, Class)
static <T> ExtensionList<T>	create(Jenkins jenkins, Class<T> type)
T	get(int index)
<U extends T> U	get(Class<U> type)	Looks for the extension instance of the given type (subclasses excluded), or return null.
List<ExtensionComponent<T>>	getComponents()	Gets the same thing as the 'this' list represents, except as ExtensionComponents.
T	getDynamic(String className)	Used to bind extension to URLs by their class names.
<U extends T> U	getInstance(Class<U> type)	Looks for the extension instance of the given type (subclasses excluded), or throws an IllegalStateException.
protected Object	getLoadLock()	Chooses the object that locks the loading of the extension instances.
Iterator<T>	iterator()
protected List<ExtensionComponent<T>>	load()	Loads all the extensions.
protected Collection<ExtensionComponent<T>>	load(ExtensionComponentSet delta)	Picks up extensions that we care from the given list.
static <T> ExtensionList<T>	lookup(Class<T> type)	Gets the extension list for a given type.
static <U> U	lookupFirst(Class<U> type)	Convenience method allowing lookup of the instance of a given type with the highest ordinal.
static <U> U	lookupSingleton(Class<U> type)	Convenience method allowing lookup of the only instance of a given type.
void	refresh(ExtensionComponentSet delta)	Used during Jenkins.refreshExtensions() to add new components into existing ExtensionLists.
final T	remove(int index)
boolean	remove(Object o)
boolean	removeAll(Collection<?> c)
List<T>	reverseView()	Gets the read-only view of this ExtensionList where components are reversed.
int	size()
protected List<ExtensionComponent<T>>	sort(List<ExtensionComponent<T>> r)	If the ExtensionList implementation requires sorting extensions, override this method to do so.

Methods inherited from class java.util.AbstractList

addAll, clear, equals, hashCode, indexOf, lastIndexOf, listIterator, listIterator, removeRange, set, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, replaceAll, retainAll, sort, spliterator, toArray, toArray

Field Details

hudson

@Deprecated
public final Hudson hudson

Deprecated.

as of 1.417 Use jenkins

jenkins

@CheckForNull
public final Jenkins jenkins

extensionType

public final Class<T> extensionType

Constructor Details

ExtensionList

@Deprecated
protected ExtensionList(Hudson hudson,
 Class<T> extensionType)

Deprecated.

as of 1.416 Use ExtensionList(Jenkins, Class)

ExtensionList

protected ExtensionList(Jenkins jenkins,
 Class<T> extensionType)

ExtensionList

@Deprecated
protected ExtensionList(Hudson hudson,
 Class<T> extensionType,
 CopyOnWriteArrayList<ExtensionComponent<T>> legacyStore)

Deprecated.

as of 1.416 Use ExtensionList(Jenkins, Class, CopyOnWriteArrayList)

ExtensionList

protected ExtensionList(Jenkins jenkins,
 Class<T> extensionType,
 CopyOnWriteArrayList<ExtensionComponent<T>> legacyStore)

Parameters:

legacyStore - Place to store manually registered instances. The version of the constructor that omits this uses a new Vector, making the storage lifespan tied to the life of ExtensionList. If the manually registered instances are scoped to VM level, the caller should pass in a static list.

Method Details

addListener

public void addListener(@NonNull
 ExtensionListListener listener)

Add a listener to the extension list.

Parameters:

listener - The listener.

get

@CheckForNull
public <U extends T> U get(@NonNull
 Class<U> type)

Looks for the extension instance of the given type (subclasses excluded), or return null.

getInstance

@NonNull
public <U extends T> U getInstance(@NonNull
 Class<U> type)
                            throws IllegalStateException

Looks for the extension instance of the given type (subclasses excluded), or throws an IllegalStateException. Meant to simplify call inside @Extension annotated class to retrieve their own instance.

Throws:

IllegalStateException

iterator

@NonNull
public Iterator<T> iterator()

Specified by:

iterator in interface Collection<T>

Specified by:

iterator in interface Iterable<T>

Specified by:

iterator in interface List<T>

Overrides:

iterator in class AbstractList<T>

getComponents

public List<ExtensionComponent<T>> getComponents()

Gets the same thing as the 'this' list represents, except as ExtensionComponents.

get

public T get(int index)

Specified by:

get in interface List<T>

Specified by:

get in class AbstractList<T>

size

public int size()

Specified by:

size in interface Collection<T>

Specified by:

size in interface List<T>

Specified by:

size in class AbstractCollection<T>

reverseView

public List<T> reverseView()

Gets the read-only view of this ExtensionList where components are reversed.

remove

public boolean remove(Object o)

Specified by:

remove in interface Collection<T>

Specified by:

remove in interface List<T>

Overrides:

remove in class AbstractCollection<T>

removeAll

public boolean removeAll(Collection<?> c)

Specified by:

removeAll in interface Collection<T>

Specified by:

removeAll in interface List<T>

Overrides:

removeAll in class AbstractCollection<T>

remove

public final T remove(int index)

Specified by:

remove in interface List<T>

Overrides:

remove in class AbstractList<T>

add

@Deprecated
public boolean add(T t)

Deprecated.

since 2009-02-23. Prefer automatic registration.

Write access will put the instance into a legacy store.

Specified by:

add in interface Collection<T>

Specified by:

add in interface List<T>

Overrides:

add in class AbstractList<T>

add

public void add(int index,
 T element)

Specified by:

add in interface List<T>

Overrides:

add in class AbstractList<T>

getDynamic

public T getDynamic(String className)

Used to bind extension to URLs by their class names.

Since:

1.349

getLoadLock

protected Object getLoadLock()

Chooses the object that locks the loading of the extension instances.

refresh

public void refresh(ExtensionComponentSet delta)

Used during Jenkins.refreshExtensions() to add new components into existing ExtensionLists. Do not call from anywhere else.

load

protected List<ExtensionComponent<T>> load()

Loads all the extensions.

load

protected Collection<ExtensionComponent<T>> load(ExtensionComponentSet delta)

Picks up extensions that we care from the given list.

sort

protected List<ExtensionComponent<T>> sort(List<ExtensionComponent<T>> r)

If the ExtensionList implementation requires sorting extensions, override this method to do so.

The implementation should copy a list, do a sort, and return the new instance.

create

@Deprecated
public static <T> ExtensionList<T> create(Hudson hudson,
 Class<T> type)

Deprecated.

as of 1.416 Use create(Jenkins, Class)

create

public static <T> ExtensionList<T> create(Jenkins jenkins,
 Class<T> type)

lookup

@NonNull
public static <T> ExtensionList<T> lookup(Class<T> type)

Gets the extension list for a given type. Normally calls Jenkins.getExtensionList(Class) but falls back to an empty list in case Jenkins.getInstanceOrNull() is null. Thus it is useful to call from all() methods which need to behave gracefully during startup or shutdown.

Parameters:

type - the extension point type

Returns:

some list

Since:

1.572

lookupSingleton

@NonNull
public static <U> U lookupSingleton(Class<U> type)

Convenience method allowing lookup of the only instance of a given type. Equivalent to ExtensionList.lookup(Class).get(Class) if there is one instance, and throws an IllegalStateException otherwise.

Parameters:

type - The type to look up.

Returns:

the singleton instance of the given type in its list.

Throws:

IllegalStateException - if there are no instances, or more than one

Since:

2.87

lookupFirst

@NonNull
public static <U> U lookupFirst(Class<U> type)

Convenience method allowing lookup of the instance of a given type with the highest ordinal. Equivalent to ExtensionList.lookup(type).get(0) if there is at least one instance, and throws an IllegalStateException otherwise if no instance could be found.

Parameters:

type - The type to look up.

Returns:

the singleton instance of the given type in its list.

Throws:

IllegalStateException - if there are no instances

Since:

2.435

clearLegacyInstances

public static void clearLegacyInstances()

Exposed for the test harness to clear all legacy extension instances.