com.vaadin.flow.internal

Class ReflectionCache<C,T>

java.lang.Object

com.vaadin.flow.internal.ReflectionCache<C,T>

Type Parameters:

C - the class types that are used as the cache keys

T - the cached value type

public class ReflectionCache<C,T>
extends Object

A thread-safe cache for the result of doing some reflection lookup based on a class. Cached values never expire since it's assumed that the there is a finite number of classes for which reflection results are used.

Since:

1.0

Author:

Vaadin Ltd

Constructor Summary

Constructors

Constructor and Description
ReflectionCache(SerializableFunction<Class<C>,T> valueProvider) Creates a new reflection cache with the given value provider.

Method Summary

Modifier and Type	Method and Description
static Registration	addClearAllAction(Runnable action) Adds an action that will be run when all reflection caches are cleared.
void	clear() Removes all mappings from this cache.
static void	clearAll() Clears all mappings from all reflection caches and related resources.
boolean	contains(Class<? extends C> type) Checks whether this cache contains an entry for the given type.
T	get(Class<? extends C> type) Gets a cached value.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionCache

public ReflectionCache(SerializableFunction<Class<C>,T> valueProvider)

Creates a new reflection cache with the given value provider. The value provider will be used to produce a new cached value whenever there is a cache miss. It will be run in a context where no CurrentInstance is available to prevent accidentally caching values that are computed differently depending on external circumstances.

Parameters:

valueProvider - a function that computes the cached value for a class, not null

Method Detail

get

public T get(Class<? extends C> type)

Gets a cached value. If this cache does not contain a value for the key, the value is computed using the configured value provider and the cache is populated with the new value.

Parameters:

type - the type for which to get reflection results

Returns:

the reflection results

contains

public boolean contains(Class<? extends C> type)

Checks whether this cache contains an entry for the given type.

Parameters:

type - the type to check for

Returns:

true if there is a mapping for the type, false if there is no mapping

clear

public void clear()

Removes all mappings from this cache.

addClearAllAction

public static Registration addClearAllAction(Runnable action)

Adds an action that will be run when all reflection caches are cleared.

The actions are held with a weak reference, which typically means that the action will be ignored if the returned registration is garbage collected.

Parameters:

action - the action to run

Returns:

a registration for removing the action

See Also:

clearAll()

clearAll

public static void clearAll()

Clears all mappings from all reflection caches and related resources.