| java.lang.Object
 org.openide.util.Lookup
All known Subclasses: org.openide.util.lookup.SimpleProxyLookup, org.openide.util.lookup.WaitableResult, org.openide.explorer.propertysheet.IndexedEditorPanel, org.openide.nodes.Node, org.netbeans.modules.openide.windows.GlobalActionContextImpl, org.openide.windows.TopComponent, org.openide.util.lookup.ProxyLookup, org.openide.util.lookup.SimpleLookup, org.openide.util.lookup.ExcludingLookup, org.openide.util.lookup.AbstractLookup, org.openide.nodes.CookieSet, org.openide.loaders.DataObject,
| Lookup | | abstract public class Lookup (Code) | | A general registry permitting clients to find instances of services
(implementation of a given interface).
This class is inspired by the
Jini
registration and lookup mechanism. The difference is that the methods do
not throw checked exceptions (as they usually work only locally and not over the network)
and that the Lookup API concentrates on the lookup, not on the registration
(although
Lookup.getDefault is strongly encouraged to support
Lookups.metaInfServices for registration in addition to whatever
else it decides to support).
For a general talk about the idea behind the lookup pattern please see
See Also: org.openide.util.lookup.AbstractLookup
See Also: Lookups
See Also: LookupListener
See Also: LookupEvent
author:
Jaroslav Tulach |
| Inner Class :public interface Provider | |
| Inner Class :final public static class Template extends Object | |
| Inner Class :abstract public static class Result extends Object | |
| Inner Class :abstract public static class Item extends Object | |
| Field Summary | |
| final public static Lookup | EMPTY
A dummy lookup that never returns any results. |
| Constructor Summary | |
| public | Lookup()
Empty constructor for use by subclasses. |
| Method Summary | |
| public static synchronized Lookup | getDefault()
Static method to obtain the global lookup in the whole system.
The actual returned implementation can be different in different
systems, but the default one is based on
org.openide.util.lookup.Lookups.metaInfServices with the context classloader of the first caller. | | abstract public T | lookup(Class<T> clazz)
Look up an object matching a given interface. | | abstract public Result<T> | lookup(Template<T> template)
The general lookup method. | | public Collection<? extends T> | lookupAll(Class<T> clazz)
Find all instances corresponding to a given class. | | public Item<T> | lookupItem(Template<T> template)
Look up the first item matching a given template. | | public Lookup.Result<T> | lookupResult(Class<T> clazz)
Find a result corresponding to a given class. |
| EMPTY | | final public static Lookup EMPTY(Code) | | A dummy lookup that never returns any results.
|
| Lookup | | public Lookup()(Code) | | Empty constructor for use by subclasses.
|
| getDefault | | public static synchronized Lookup getDefault()(Code) | | Static method to obtain the global lookup in the whole system.
The actual returned implementation can be different in different
systems, but the default one is based on
org.openide.util.lookup.Lookups.metaInfServices with the context classloader of the first caller. Each system is
adviced to honor this and include some form of metaInfServices
implementation in the returned lookup as usage of META-INF/services
is a JDK standard.
the global lookup in the system |
| lookup | | abstract public T lookup(Class<T> clazz)(Code) | | Look up an object matching a given interface.
This is the simplest method to use.
If more than one object matches, the first will be returned.
The template class may be a class or interface; the instance is
guaranteed to be assignable to it.
Parameters:
clazz - class of the object we are searching for an object implementing the given class or null if no suchimplementation is found |
| lookup | | abstract public Result<T> lookup(Template<T> template)(Code) | | The general lookup method. Callers can get list of all instances and classes
that match the given template, request more info about
them in form of
Lookup.Item and attach a listener to
this be notified about changes. The general interface does not
specify whether subsequent calls with the same template produce new
instance of the
Lookup.Result or return shared instance. The
prefered behaviour however is to return shared one.
Parameters:
template - a template describing the services to look for an object containing the results |
| lookupAll | | public Collection<? extends T> lookupAll(Class<T> clazz)(Code) | | Find all instances corresponding to a given class.
Equivalent to calling
Lookup.lookupResult and asking for
Lookup.Result.allInstances but slightly more convenient.
Subclasses may override this method to produce the same semantics more efficiently.
Parameters:
clazz - the supertype of the result all currently available instances of that type
since:
org.openide.util 6.10 |
| lookupItem | | public Item<T> lookupItem(Template<T> template)(Code) | | Look up the first item matching a given template.
Includes not only the instance but other associated information.
Parameters:
template - the template to check a matching item or null
since:
1.8 |
| lookupResult | | public Lookup.Result<T> lookupResult(Class<T> clazz)(Code) | | Find a result corresponding to a given class.
Equivalent to calling
Lookup.lookup(Lookup.Template) but slightly more convenient.
Subclasses may override this method to produce the same semantics more efficiently.
Parameters:
clazz - the supertype of the result a live object representing instances of that type
since:
org.openide.util 6.10 |
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