java.lang.Object
- org.ow2.authzforce.core.pdp.api.HashCollections

```
public final class HashCollections
extends Object
```
Static factory methods to construct HashMaps/HashSets based on alternatives to Java native implementations, which alternatives must support:
1. Immutable HashMap/HashSet implementations. By default, Guava ImmutableMap/ImmutableSet factory is used.
2. Mutable HashMap/HashSet implementations accepting an expected size as constructor parameter. By default, Guava Maps/Sets factory is used.
Ideally, the alternative should support updatable HashMaps/HashSets accepting an expected size as constructor parameter as well. (Guava does not provide such implementation so the mutable variant from Maps/Sets is used by default instead.)
See Also:

"http://java-performance.info/hashmap-overview-jdk-fastutil-goldman-sachs-hppc-koloboke-trove-january-2015/"

Field Summary

Fields
Modifier and Type Field Description

static String HASH_COLLECTION_FACTORY_SYSTEM_PROPERTY_NAME
Name of system property for setting the HashCollectionFactory implementation class.

Constructor Summary

Constructors
Constructor Description

HashCollections()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static <K,V> Map<K,V>`	`newImmutableMap(Map<? extends K,? extends V> map)`	Constructs a new immutable map with the same mappings as the specified map.
`static <K,V> Map<K,V>`	`newImmutableMap(Map<? extends K,? extends V> map1, Map<? extends K,? extends V> map2)`	Constructs a new immutable map which merges the mappings of the specified maps.
`static <K,V> Map<K,V>`	`newImmutableMap(K k1, V v1)`	Constructs a new immutable map of the single specified mapping.
`static <K,V> Map<K,V>`	`newImmutableMap(K k1, V v1, K k2, V v2)`	Constructs a new immutable map of the two specified mappings.
`static <K,V> Map<K,V>`	`newImmutableMap(K k1, V v1, K k2, V v2, K k3, V v3)`	Constructs a new immutable map of the three specified mappings.
`static <E> Set<E>`	`newImmutableSet(E e1)`	Constructs a new immutable singleton set of the given element.
`static <E> Set<E>`	`newImmutableSet(E[] elements)`	Constructs a new immutable set of elements from the given array.
`static <E> Set<E>`	`newImmutableSet(Iterable<? extends E> elements)`	Constructs a new immutable set containing the elements in the specified iterable.
`static <E> Set<E>`	`newImmutableSet(Set<? extends E> set1, Set<? extends E> set2)`	Constructs a new immutable set which merges the elements of the specified sets.
`static <K,V> Map<K,V>`	`newMutableMap()`	Constructs a new empty mutable map of the default expected size (depending on the underlying implementation).
`static <K,V> Map<K,V>`	`newUpdatableMap()`	Constructs a new empty updatable map of the default expected size (depending on the underlying implementation).
`static <K,V> Map<K,V>`	`newUpdatableMap(int expectedSize)`	Constructs a new empty updatable map of the given expected size.
`static <K,V> Map<K,V>`	`newUpdatableMap(Map<? extends K,? extends V> map)`	Constructs a new updatable map with the same mappings as the specified map.
`static <K,V> Map<K,V>`	`newUpdatableMap(Map<? extends K,? extends V> map1, Map<? extends K,? extends V> map2)`	Constructs a new updatable map which merge the mappings of the specified maps.
`static <K,V> Map<K,V>`	`newUpdatableMap(Map<? extends K,? extends V> map1, Map<? extends K,? extends V> map2, Map<? extends K,? extends V> map3)`	Constructs a new updatable map which merge the mappings of the specified maps.
`static <E> Set<E>`	`newUpdatableSet()`	Constructs a new empty updatable set of the default expected size (depending on the underlying implementation).
`static <E> Set<E>`	`newUpdatableSet(int expectedSize)`	Constructs a new empty updatable set of the given expected size.
`static <E> Set<E>`	`newUpdatableSet(Iterable<? extends E> elements)`	Constructs a new updatable set containing the elements in the specified iterable.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - HASH_COLLECTION_FACTORY_SYSTEM_PROPERTY_NAME
```
public static final String HASH_COLLECTION_FACTORY_SYSTEM_PROPERTY_NAME
```
    Name of system property for setting the HashCollectionFactory implementation class. Default: DefaultHashCollectionFactory.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - HashCollections
```
public HashCollections()
```
- Method Detail
  - newMutableMap
```
public static <K,V> Map<K,V> newMutableMap()
```
    Constructs a new empty mutable map of the default expected size (depending on the underlying implementation).
    
    Returns:
    
    a new empty mutable map
  - newUpdatableMap
```
public static <K,V> Map<K,V> newUpdatableMap()
```
    Constructs a new empty updatable map of the default expected size (depending on the underlying implementation).
    
    Returns:
    
    new empty updatable map
  - newUpdatableMap
```
public static <K,V> Map<K,V> newUpdatableMap(int expectedSize)
```
    Constructs a new empty updatable map of the given expected size.
    
    Parameters:
    
    expectedSize - expected size of the returned map
    
    Returns:
    
    a new empty updatable map of the given expected size
  - newUpdatableMap
```
public static <K,V> Map<K,V> newUpdatableMap(Map<? extends K,? extends V> map)
```
    Constructs a new updatable map with the same mappings as the specified map.
    
    Parameters:
    
    map - the map whose mappings are to be placed in the returned map
    
    Returns:
    
    a new updatable map with the same mappings as the specified map
  - newUpdatableMap
```
public static <K,V> Map<K,V> newUpdatableMap(Map<? extends K,? extends V> map1,
                                                         Map<? extends K,? extends V> map2)
```
    Constructs a new updatable map which merge the mappings of the specified maps. On conflict, mappings from the map2 have priority over mappings from the map1 with the same keys.
    
    Parameters:
    
    map1 - the first map to merge
    
    map2 - the second map to merge
    
    Returns:
    
    a new updatable map which merges the mappings of the specified maps
  - newUpdatableMap
```
public static <K,V> Map<K,V> newUpdatableMap(Map<? extends K,? extends V> map1,
                                                         Map<? extends K,? extends V> map2,
                                                         Map<? extends K,? extends V> map3)
```
    Constructs a new updatable map which merge the mappings of the specified maps. On conflict, mappings from the maps passed later in the argument list have priority over mappings from the maps passed earlier with the same keys.
    
    Parameters:
    
    map1 - the first map to merge
    
    map2 - the second map to merge
    
    map3 - the third map to merge
    
    Returns:
    
    a new updatable map which merges the mappings of the specified maps
  - newImmutableMap
```
public static <K,V> Map<K,V> newImmutableMap(Map<? extends K,? extends V> map)
```
    Constructs a new immutable map with the same mappings as the specified map.
    
    Parameters:
    
    map - the map whose mappings are to be placed in the returned map
    
    Returns:
    
    a new immutable map with the same mappings as the specified map
  - newImmutableMap
```
public static <K,V> Map<K,V> newImmutableMap(Map<? extends K,? extends V> map1,
                                                         Map<? extends K,? extends V> map2)
```
    Constructs a new immutable map which merges the mappings of the specified maps. On conflict, mappings from the map2 have priority over mappings from the map1 with the same keys.
    
    Parameters:
    
    map1 - the first map to merge
    
    map2 - the second map to merge
    
    Returns:
    
    a new immutable map which merges the mappings of the specified maps
  - newImmutableMap
```
public static <K,V> Map<K,V> newImmutableMap(K k1,
                                                         V v1)
```
    Constructs a new immutable map of the single specified mapping.
    
    Parameters:
    
    k1 - the key of the sole mapping
    
    v1 - the value of the sole mapping
    
    Returns:
    
    a new immutable map of the single specified mapping
  - newImmutableMap
```
public static <K,V> Map<K,V> newImmutableMap(K k1,
                                                         V v1,
                                                         K k2,
                                                         V v2)
```
    Constructs a new immutable map of the two specified mappings.
    
    Parameters:
    
    k1 - the key of the first mapping
    
    v1 - the value of the first mapping
    
    k2 - the key of the second mapping
    
    v2 - the value of the second mapping
    
    Returns:
    
    Returns an immutable map containing the given entries, in order.
  - newImmutableMap
```
public static <K,V> Map<K,V> newImmutableMap(K k1,
                                                         V v1,
                                                         K k2,
                                                         V v2,
                                                         K k3,
                                                         V v3)
```
    Constructs a new immutable map of the three specified mappings.
    
    Parameters:
    
    k1 - the key of the first mapping
    
    v1 - the value of the first mapping
    
    k2 - the key of the second mapping
    
    v2 - the value of the second mapping
    
    k3 - the key of the third mapping
    
    v3 - the value of the third mapping
    
    Returns:
    
    Returns an immutable map containing the given entries, in order.
  - newUpdatableSet
```
public static <E> Set<E> newUpdatableSet()
```
    Constructs a new empty updatable set of the default expected size (depending on the underlying implementation).
    
    Returns:
    
    a new empty updatable set
  - newUpdatableSet
```
public static <E> Set<E> newUpdatableSet(int expectedSize)
```
    Constructs a new empty updatable set of the given expected size.
    
    Parameters:
    
    expectedSize - the expected size of the returned set
    
    Returns:
    
    a new empty updatable set of the given expected size
  - newUpdatableSet
```
public static <E> Set<E> newUpdatableSet(Iterable<? extends E> elements)
```
    Constructs a new updatable set containing the elements in the specified iterable.
    
    Parameters:
    
    elements - the iterable whose elements are to be placed into the returned set
    
    Returns:
    
    a new updatable set of the elements of the specified iterable
  - newImmutableSet
```
public static <E> Set<E> newImmutableSet(E[] elements)
```
    Constructs a new immutable set of elements from the given array.
    
    Parameters:
    
    elements - the array whose elements are to be placed into the returned set
    
    Returns:
    
    a new immutable set of elements from the given array
  - newImmutableSet
```
public static <E> Set<E> newImmutableSet(Set<? extends E> set1,
                                         Set<? extends E> set2)
```
    Constructs a new immutable set which merges the elements of the specified sets.
    
    Parameters:
    
    set1 - the first source of elements for the returned set
    
    set2 - the second source of elements for the returned set
    
    Returns:
    
    a new immutable set which merges the elements of the specified sets
  - newImmutableSet
```
public static <E> Set<E> newImmutableSet(Iterable<? extends E> elements)
```
    Constructs a new immutable set containing the elements in the specified iterable.
    
    Parameters:
    
    elements - the iterable whose elements are to be placed into the returned set
    
    Returns:
    
    a new immutable set of the elements of the specified iterable
  - newImmutableSet
```
public static <E> Set<E> newImmutableSet(E e1)
```
    Constructs a new immutable singleton set of the given element.
    
    Parameters:
    
    e1 - the sole element
    
    Returns:
    
    a new immutable singleton set of the given element

Class HashCollections

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

HASH_COLLECTION_FACTORY_SYSTEM_PROPERTY_NAME

Constructor Detail

HashCollections

Method Detail

newMutableMap

newUpdatableMap

newUpdatableMap

newUpdatableMap

newUpdatableMap

newUpdatableMap

newImmutableMap

newImmutableMap

newImmutableMap

newImmutableMap

newImmutableMap

newUpdatableSet

newUpdatableSet

newUpdatableSet

newImmutableSet

newImmutableSet

newImmutableSet

newImmutableSet