org.springframework.core

类 CollectionFactory

java.lang.Object

org.springframework.core.CollectionFactory

public abstract class CollectionFactory
extends Object

Factory for collections that is aware of common Java and Spring collection types.

Mainly for internal use within the framework.

从以下版本开始:

1.1.1

作者:

Juergen Hoeller, Arjen Poutsma, Oliver Gierke, Sam Brannen

构造器概要

构造器

构造器和说明
CollectionFactory()

方法概要

限定符和类型	方法和说明
static <E> Collection<E>	createApproximateCollection(Object collection, int capacity) Create the most approximate collection for the given collection.
static <K,V> Map<K,V>	createApproximateMap(Object map, int capacity) Create the most approximate map for the given map.
static <E> Collection<E>	createCollection(Class<?> collectionType, Class<?> elementType, int capacity) Create the most appropriate collection for the given collection type.
static <E> Collection<E>	createCollection(Class<?> collectionType, int capacity) Create the most appropriate collection for the given collection type.
static <K,V> Map<K,V>	createMap(Class<?> mapType, Class<?> keyType, int capacity) Create the most appropriate map for the given map type.
static <K,V> Map<K,V>	createMap(Class<?> mapType, int capacity) Create the most appropriate map for the given map type.
static Properties	createStringAdaptingProperties() Create a variant of java.util.Properties that automatically adapts non-String values to String representations on Properties.getProperty(java.lang.String).
static boolean	isApproximableCollectionType(Class<?> collectionType) Determine whether the given collection type is an approximable type, i.e. a type that createApproximateCollection(java.lang.Object, int) can approximate.
static boolean	isApproximableMapType(Class<?> mapType) Determine whether the given map type is an approximable type, i.e. a type that createApproximateMap(java.lang.Object, int) can approximate.

从类继承的方法 java.lang.Object

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

构造器详细资料

CollectionFactory

public CollectionFactory()

方法详细资料

isApproximableCollectionType

public static boolean isApproximableCollectionType(@Nullable
                                                   Class<?> collectionType)

Determine whether the given collection type is an approximable type, i.e. a type that createApproximateCollection(java.lang.Object, int) can approximate.

参数:

collectionType - the collection type to check

返回:

true if the type is approximable

createApproximateCollection

public static <E> Collection<E> createApproximateCollection(@Nullable
                                                            Object collection,
                                                            int capacity)

Create the most approximate collection for the given collection.

Warning: Since the parameterized type E is not bound to the type of elements contained in the supplied collection, type safety cannot be guaranteed if the supplied collection is an EnumSet. In such scenarios, the caller is responsible for ensuring that the element type for the supplied collection is an enum type matching type E. As an alternative, the caller may wish to treat the return value as a raw collection or collection of Object.

参数:

collection - the original collection object, potentially null

capacity - the initial capacity

返回:

a new, empty collection instance

另请参阅:

isApproximableCollectionType(java.lang.Class<?>), LinkedList, ArrayList, EnumSet, TreeSet, LinkedHashSet

createCollection

public static <E> Collection<E> createCollection(Class<?> collectionType,
                                                 int capacity)

Create the most appropriate collection for the given collection type.

Delegates to createCollection(Class, Class, int) with a null element type.

参数:

collectionType - the desired type of the target collection (never null)

capacity - the initial capacity

返回:

a new collection instance

抛出:

IllegalArgumentException - if the supplied collectionType is null or of type EnumSet

createCollection

public static <E> Collection<E> createCollection(Class<?> collectionType,
                                                 @Nullable
                                                 Class<?> elementType,
                                                 int capacity)

Create the most appropriate collection for the given collection type.

Warning: Since the parameterized type E is not bound to the supplied elementType, type safety cannot be guaranteed if the desired collectionType is EnumSet. In such scenarios, the caller is responsible for ensuring that the supplied elementType is an enum type matching type E. As an alternative, the caller may wish to treat the return value as a raw collection or collection of Object.

参数:

collectionType - the desired type of the target collection (never null)

elementType - the collection's element type, or null if unknown (note: only relevant for EnumSet creation)

capacity - the initial capacity

返回:

a new collection instance

抛出:

IllegalArgumentException - if the supplied collectionType is null; or if the desired collectionType is EnumSet and the supplied elementType is not a subtype of Enum

从以下版本开始:

4.1.3

另请参阅:

LinkedHashSet, ArrayList, TreeSet, EnumSet

isApproximableMapType

public static boolean isApproximableMapType(@Nullable
                                            Class<?> mapType)

Determine whether the given map type is an approximable type, i.e. a type that createApproximateMap(java.lang.Object, int) can approximate.

参数:

mapType - the map type to check

返回:

true if the type is approximable

createApproximateMap

public static <K,V> Map<K,V> createApproximateMap(@Nullable
                                                  Object map,
                                                  int capacity)

Create the most approximate map for the given map.

Warning: Since the parameterized type K is not bound to the type of keys contained in the supplied map, type safety cannot be guaranteed if the supplied map is an EnumMap. In such scenarios, the caller is responsible for ensuring that the key type in the supplied map is an enum type matching type K. As an alternative, the caller may wish to treat the return value as a raw map or map keyed by Object.

参数:

map - the original map object, potentially null

capacity - the initial capacity

返回:

a new, empty map instance

另请参阅:

isApproximableMapType(java.lang.Class<?>), EnumMap, TreeMap, LinkedHashMap

createMap

public static <K,V> Map<K,V> createMap(Class<?> mapType,
                                       int capacity)

Create the most appropriate map for the given map type.

Delegates to createMap(Class, Class, int) with a null key type.

参数:

mapType - the desired type of the target map

capacity - the initial capacity

返回:

a new map instance

抛出:

IllegalArgumentException - if the supplied mapType is null or of type EnumMap

createMap

public static <K,V> Map<K,V> createMap(Class<?> mapType,
                                       @Nullable
                                       Class<?> keyType,
                                       int capacity)

Create the most appropriate map for the given map type.

Warning: Since the parameterized type K is not bound to the supplied keyType, type safety cannot be guaranteed if the desired mapType is EnumMap. In such scenarios, the caller is responsible for ensuring that the keyType is an enum type matching type K. As an alternative, the caller may wish to treat the return value as a raw map or map keyed by Object. Similarly, type safety cannot be enforced if the desired mapType is MultiValueMap.

参数:

mapType - the desired type of the target map (never null)

keyType - the map's key type, or null if unknown (note: only relevant for EnumMap creation)

capacity - the initial capacity

返回:

a new map instance

抛出:

IllegalArgumentException - if the supplied mapType is null; or if the desired mapType is EnumMap and the supplied keyType is not a subtype of Enum

从以下版本开始:

4.1.3

另请参阅:

LinkedHashMap, TreeMap, LinkedMultiValueMap, EnumMap

createStringAdaptingProperties

public static Properties createStringAdaptingProperties()

Create a variant of java.util.Properties that automatically adapts non-String values to String representations on Properties.getProperty(java.lang.String).

返回:

a new Properties instance

从以下版本开始:

4.3.4