ListHashMap (Groovy 6.0.0-alpha-2)

org.codehaus.groovy.util.ListHashMap

All Implemented Interfaces and Traits:

Map
```
public class ListHashMap<K, V>
extends Object
implements Map
```
Represents a Map that is optimized for a small number of entries. For a number of entries up to listSize the entries are stored in arrays. After listSize entries are exceeded storage switches internally to a Map and converts back to being array based when its size is less than or equal to listSize.
Null keys or values are not supported.
This class is not thread-safe!

Constructor Summary

Constructors
Constructor and description
`ListHashMap()` Creates a map that keeps up to three entries in array-backed storage.
`ListHashMap(int listSize)` Creates a map that keeps up to `listSize` entries in array-backed storage.

Methods Summary

Methods
Type Params	Return Type	Name and description
	`public void`	`clear()` Removes all of the mappings from this map (optional operation). The map will be empty after this call returns. throws: UnsupportedOperationException if the `clear` operation is not supported by this map
	`public boolean`	`containsKey(Object key)` Returns `true` if this map contains a mapping for the specified key. More formally, returns `true` if and only if this map contains a mapping for a key `k` such that `Objects.equals(key, k)`. (There can be at most one such mapping.) throws: ClassCastException if the key is of an inappropriate type for this map (optional) throws: NullPointerException if the specified key is null and this map does not permit null keys (optional) Parameters: `key` - key whose presence in this map is to be tested Returns: `true` if this map contains a mapping for the specified key
	`public boolean`	`containsValue(Object value)` Returns `true` if this map maps one or more keys to the specified value. More formally, returns `true` if and only if this map contains at least one mapping to a value `v` such that `Objects.equals(value, v)`. This operation will probably require time linear in the map size for most implementations of the `Map` interface. throws: ClassCastException if the value is of an inappropriate type for this map (optional) throws: NullPointerException if the specified value is null and this map does not permit null values (optional) Parameters: `value` - value whose presence in this map is to be tested Returns: `true` if this map maps one or more keys to the specified value
	`public Set<Entry<K, V>>`	`entrySet()` Returns a Set view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own `remove` operation, or through the `setValue` operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`, `removeAll`, `retainAll` and `clear` operations. It does not support the `add` or `addAll` operations. Returns: a set view of the mappings contained in this map
	`public V`	`get(Object key)` Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. More formally, if this map contains a mapping from a key `k` to a value `v` such that `Objects.equals(key, k)`, then this method returns `v`; otherwise it returns `null`. (There can be at most one such mapping.) If this map permits null values, then a return value of `null` does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to `null`. The containsKey operation may be used to distinguish these two cases. throws: ClassCastException if the key is of an inappropriate type for this map (optional) throws: NullPointerException if the specified key is null and this map does not permit null keys (optional) Parameters: `key` - the key whose associated value is to be returned Returns: the value to which the specified key is mapped, or `null` if this map contains no mapping for the key
	`public boolean`	`isEmpty()` Returns `true` if this map contains no key-value mappings. Returns: `true` if this map contains no key-value mappings
	`public Set<K>`	`keySet()` Returns a Set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`, `removeAll`, `retainAll`, and `clear` operations. It does not support the `add` or `addAll` operations. Returns: a set view of the keys contained in this map
	`public V`	`put(K key, V value)` Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map `m` is said to contain a mapping for a key `k` if and only if containsKey(Object) m.containsKey(k) would return `true`.) throws: UnsupportedOperationException if the `put` operation is not supported by this map throws: ClassCastException if the class of the specified key or value prevents it from being stored in this map throws: NullPointerException if the specified key or value is null and this map does not permit null keys or values throws: IllegalArgumentException if some property of the specified key or value prevents it from being stored in this map Parameters: `key` - key with which the specified value is to be associated `value` - value to be associated with the specified key Returns: the previous value associated with `key`, or `null` if there was no mapping for `key`. (A `null` return can also indicate that the map previously associated `null` with `key`, if the implementation supports `null` values.)
	`public void`	`putAll(Map<? extends K, ? extends V> m)` Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(Object,Object) put(k, v) on this map once for each mapping from key `k` to value `v` in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress. throws: UnsupportedOperationException if the `putAll` operation is not supported by this map throws: ClassCastException if the class of a key or value in the specified map prevents it from being stored in this map throws: NullPointerException if the specified map is null, or if this map does not permit null keys or values, and the specified map contains null keys or values throws: IllegalArgumentException if some property of a key or value in the specified map prevents it from being stored in this map Parameters: `m` - mappings to be stored in this map
	`public V`	`remove(Object key)` Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key `k` to value `v` such that `Objects.equals(key, k)`, that mapping is removed. (The map can contain at most one such mapping.) Returns the value to which this map previously associated the key, or `null` if the map contained no mapping for the key. If this map permits null values, then a return value of `null` does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to `null`. The map will not contain a mapping for the specified key once the call returns. throws: UnsupportedOperationException if the `remove` operation is not supported by this map throws: ClassCastException if the key is of an inappropriate type for this map (optional) throws: NullPointerException if the specified key is null and this map does not permit null keys (optional) Parameters: `key` - key whose mapping is to be removed from the map Returns: the previous value associated with `key`, or `null` if there was no mapping for `key`.
	`public int`	`size()` Returns the number of key-value mappings in this map. If the map contains more than `Integer.MAX_VALUE` elements, returns `Integer.MAX_VALUE`. Returns: the number of key-value mappings in this map
	`public Collection<V>`	`values()` Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Collection.remove`, `removeAll`, `retainAll` and `clear` operations. It does not support the `add` or `addAll` operations. Returns: a collection view of the values contained in this map

Inherited Methods Summary

Inherited Methods
Methods inherited from class	Name
`class Object`	`equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- Constructor Detail
  - public ListHashMap()
    
    Creates a map that keeps up to three entries in array-backed storage.
  - public ListHashMap(int listSize)
    
    Creates a map that keeps up to listSize entries in array-backed storage.
    Parameters:
    listSize - the number of entries to keep in arrays before promoting to a backing map
- Method Detail
  - public void clear()
    
    Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.
    throws:
    UnsupportedOperationException if the clear operation is not supported by this map
  - public boolean containsKey(Object key)
    
    Returns true if this map contains a mapping for the specified key. More formally, returns true if and only if this map contains a mapping for a key k such that Objects.equals(key, k). (There can be at most one such mapping.)
    throws:
    ClassCastException if the key is of an inappropriate type for this map (optional)
    throws:
    NullPointerException if the specified key is null and this map does not permit null keys (optional)
    
    Parameters:
    key - key whose presence in this map is to be tested
    Returns:
    true if this map contains a mapping for the specified key
  - public boolean containsValue(Object value)
    
    Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that Objects.equals(value, v). This operation will probably require time linear in the map size for most implementations of the Map interface.
    throws:
    ClassCastException if the value is of an inappropriate type for this map (optional)
    throws:
    NullPointerException if the specified value is null and this map does not permit null values (optional)
    
    Parameters:
    value - value whose presence in this map is to be tested
    Returns:
    true if this map maps one or more keys to the specified value
  - public Set<Entry<K, V>> entrySet()
    
    Returns a Set view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation, or through the setValue operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.
    Returns:
    a set view of the mappings contained in this map
  - public V get(Object key)
    
    Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.
    More formally, if this map contains a mapping from a key k to a value v such that Objects.equals(key, k), then this method returns v; otherwise it returns null. (There can be at most one such mapping.)
    If this map permits null values, then a return value of null does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to null. The containsKey operation may be used to distinguish these two cases.
    throws:
    ClassCastException if the key is of an inappropriate type for this map (optional)
    throws:
    NullPointerException if the specified key is null and this map does not permit null keys (optional)
    
    Parameters:
    key - the key whose associated value is to be returned
    Returns:
    the value to which the specified key is mapped, or null if this map contains no mapping for the key
  - public boolean isEmpty()
    
    Returns true if this map contains no key-value mappings.
    Returns:
    true if this map contains no key-value mappings
  - public Set<K> keySet()
    
    Returns a Set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.
    Returns:
    a set view of the keys contained in this map
  - public V put(K key, V value)
    
    Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if containsKey(Object) m.containsKey(k) would return true.)
    throws:
    UnsupportedOperationException if the put operation is not supported by this map
    throws:
    ClassCastException if the class of the specified key or value prevents it from being stored in this map
    throws:
    NullPointerException if the specified key or value is null and this map does not permit null keys or values
    throws:
    IllegalArgumentException if some property of the specified key or value prevents it from being stored in this map
    
    Parameters:
    key - key with which the specified value is to be associated
    value - value to be associated with the specified key
    Returns:
    the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key, if the implementation supports null values.)
  - public void putAll(Map<? extends K, ? extends V> m)
    
    Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(Object,Object) put(k, v) on this map once for each mapping from key k to value v in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress.
    throws:
    UnsupportedOperationException if the putAll operation is not supported by this map
    throws:
    ClassCastException if the class of a key or value in the specified map prevents it from being stored in this map
    throws:
    NullPointerException if the specified map is null, or if this map does not permit null keys or values, and the specified map contains null keys or values
    throws:
    IllegalArgumentException if some property of a key or value in the specified map prevents it from being stored in this map
    
    Parameters:
    m - mappings to be stored in this map
  - public V remove(Object key)
    
    Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key k to value v such that Objects.equals(key, k), that mapping is removed. (The map can contain at most one such mapping.)
    Returns the value to which this map previously associated the key, or null if the map contained no mapping for the key.
    If this map permits null values, then a return value of null does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to null.
    The map will not contain a mapping for the specified key once the call returns.
    throws:
    UnsupportedOperationException if the remove operation is not supported by this map
    throws:
    ClassCastException if the key is of an inappropriate type for this map (optional)
    throws:
    NullPointerException if the specified key is null and this map does not permit null keys (optional)
    
    Parameters:
    key - key whose mapping is to be removed from the map
    Returns:
    the previous value associated with key, or null if there was no mapping for key.
  - public int size()
    
    Returns the number of key-value mappings in this map. If the map contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.
    Returns:
    the number of key-value mappings in this map
  - public Collection<V> values()
    
    Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.
    Returns:
    a collection view of the values contained in this map

Summary:
Constructor
Method

| Detail:
Constructor
Method

[Java] Class ListHashMap<K, V>

Constructor Summary

Methods Summary

Inherited Methods Summary

Constructor Detail

public ListHashMap()

public ListHashMap(int listSize)

Method Detail

public void clear()

public boolean containsKey(Object key)

public boolean containsValue(Object value)

public Set<Entry<K, V>> entrySet()

public V get(Object key)

public boolean isEmpty()

public Set<K> keySet()

public V put(K key, V value)

public void putAll(Map<? extends K, ? extends V> m)

public V remove(Object key)

public int size()

public Collection<V> values()