AbstractMap4D (TotalCrossSDK 6.1.0 API)

java.lang.Object
- totalcross.util.AbstractMap4D<K,V>

All Implemented Interfaces:

java.util.Map<K,V>

Direct Known Subclasses:

EnumMap4D, HashMap4D, IdentityHashMap4D, TreeMap4D
```
public abstract class AbstractMap4D<K,V>
extends java.lang.Object
implements java.util.Map<K,V>
```
An abstract implementation of Map to make it easier to create your own implementations. In order to create an unmodifiable Map, subclass AbstractMap and implement the entrySet (usually via an AbstractSet). To make it modifiable, also implement put, and have entrySet().iterator() support remove.
It is recommended that classes which extend this support at least the no-argument constructor, and a constructor which accepts another Map. Further methods in this class may be overridden if you have a more efficient implementation.

Since:

1.2

See Also:

Map, Collection, HashMap, LinkedHashMap, TreeMap, WeakHashMap, IdentityHashMap

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`AbstractMap4D.SimpleEntry<K,V>` A class which implements Map.Entry.
`static class`	`AbstractMap4D.SimpleImmutableEntry<K,V>` A class containing an immutable key and value.

Nested classes/interfaces inherited from interface java.util.Map
java.util.Map.Entry<K,V>

Constructor Summary

Constructors
Modifier Constructor and Description

protected AbstractMap4D()
The main constructor, for use by subclasses.

Constructors
Modifier	Constructor and Description
`protected`	`AbstractMap4D()` The main constructor, for use by subclasses.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clear()` Remove all entries from this Map (optional operation).
`protected java.lang.Object`	`clone()` Create a shallow copy of this Map, no keys or values are copied.
`boolean`	`containsKey(java.lang.Object key)` Returns true if this contains a mapping for the given key.
`boolean`	`containsValue(java.lang.Object value)` Returns true if this contains at least one mapping with the given value.
`abstract java.util.Set<java.util.Map.Entry<K,V>>`	`entrySet()` Returns a set view of the mappings in this Map.
`boolean`	`equals(java.lang.Object o)` Compares the specified object with this map for equality.
`static boolean`	`equals(java.lang.Object o1, java.lang.Object o2)` Compare two objects according to Collection semantics.
`V`	`get(java.lang.Object key)` Returns the value mapped by the given key.
`int`	`hashCode()` Returns the hash code for this map.
`static int`	`hashCode(java.lang.Object o)` Hash an object according to Collection semantics.
`boolean`	`isEmpty()` Returns true if the map contains no mappings.
`java.util.Set<K>`	`keySet()` Returns a set view of this map's keys.
`V`	`put(K key, V value)` Associates the given key to the given value (optional operation).
`void`	`putAll(java.util.Map<? extends K,? extends V> m)` Copies all entries of the given map to this one (optional operation).
`V`	`remove(java.lang.Object key)` Removes the mapping for this key if present (optional operation).
`int`	`size()` Returns the number of key-value mappings in the map.
`java.lang.String`	`toString()` Returns a String representation of this map.
`java.util.Collection<V>`	`values()` Returns a collection or bag view of this map's values.

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

- Constructor Detail
  - AbstractMap4D
```
protected AbstractMap4D()
```
    The main constructor, for use by subclasses.
- Method Detail
  - entrySet
```
public abstract java.util.Set<java.util.Map.Entry<K,V>> entrySet()
```
    Returns a set view of the mappings in this Map. Each element in the set must be an implementation of Map.Entry. The set is backed by the map, so that changes in one show up in the other. Modifications made while an iterator is in progress cause undefined behavior. If the set supports removal, these methods must be valid: Iterator.remove, Set.remove, removeAll, retainAll, and clear. Element addition is not supported via this set.
    
    Specified by:
    
    entrySet in interface java.util.Map<K,V>
    
    Returns:
    
    the entry set
    
    See Also:
    
    Map.Entry
  - clear
```
public void clear()
```
    Remove all entries from this Map (optional operation). This default implementation calls entrySet().clear(). NOTE: If the entry set does not permit clearing, then this will fail, too. Subclasses often override this for efficiency. Your implementation of entrySet() should not call AbstractMap.clear unless you want an infinite loop.
    
    Specified by:
    
    clear in interface java.util.Map<K,V>
    
    Throws:
    
    java.lang.UnsupportedOperationException - if entrySet().clear() does not support clearing.
    
    See Also:
    
    Set.clear()
  - clone
```
protected java.lang.Object clone()
                          throws java.lang.CloneNotSupportedException
```
    Create a shallow copy of this Map, no keys or values are copied. The default implementation simply calls super.clone().
    
    Overrides:
    
    clone in class java.lang.Object
    
    Returns:
    
    the shallow clone
    
    Throws:
    
    java.lang.CloneNotSupportedException - if a subclass is not Cloneable
    
    See Also:
    
    Cloneable, Object.clone()
  - containsKey
```
public boolean containsKey(java.lang.Object key)
```
    Returns true if this contains a mapping for the given key. This implementation does a linear search, O(n), over the entrySet(), returning true if a match is found, false if the iteration ends. Many subclasses can implement this more efficiently.
    
    Specified by:
    
    containsKey in interface java.util.Map<K,V>
    
    Parameters:
    
    key - the key to search for
    
    Returns:
    
    true if the map contains the key
    
    Throws:
    
    java.lang.NullPointerException - if key is null but the map does not permit null keys
    
    See Also:
    
    containsValue(Object)
  - containsValue
```
public boolean containsValue(java.lang.Object value)
```
    Returns true if this contains at least one mapping with the given value. This implementation does a linear search, O(n), over the entrySet(), returning true if a match is found, false if the iteration ends. A match is defined as a value, v, where (value == null ? v == null : value.equals(v)). Subclasses are unlikely to implement this more efficiently.
    
    Specified by:
    
    containsValue in interface java.util.Map<K,V>
    
    Parameters:
    
    value - the value to search for
    
    Returns:
    
    true if the map contains the value
    
    See Also:
    
    containsKey(Object)
  - equals
```
public boolean equals(java.lang.Object o)
```
    Compares the specified object with this map for equality. Returns true if the other object is a Map with the same mappings, that is,
    o instanceof Map && entrySet().equals(((Map) o).entrySet();
    
    Specified by:
    
    equals in interface java.util.Map<K,V>
    
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    o - the object to be compared
    
    Returns:
    
    true if the object equals this map
    
    See Also:
    
    Set.equals(Object)
  - get
```
public V get(java.lang.Object key)
```
    Returns the value mapped by the given key. Returns null if there is no mapping. However, in Maps that accept null values, you must rely on containsKey to determine if a mapping exists. This iteration takes linear time, searching entrySet().iterator() of the key. Many implementations override this method.
    
    Specified by:
    
    get in interface java.util.Map<K,V>
    
    Parameters:
    
    key - the key to look up
    
    Returns:
    
    the value associated with the key, or null if key not in map
    
    Throws:
    
    java.lang.NullPointerException - if this map does not accept null keys
    
    See Also:
    
    containsKey(Object)
  - hashCode
```
public int hashCode()
```
    Returns the hash code for this map. As defined in Map, this is the sum of all hashcodes for each Map.Entry object in entrySet, or basically entrySet().hashCode().
    
    Specified by:
    
    hashCode in interface java.util.Map<K,V>
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    the hash code
    
    See Also:
    
    Map.Entry#hashCode(), Set.hashCode()
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if the map contains no mappings. This is implemented by size() == 0.
    
    Specified by:
    
    isEmpty in interface java.util.Map<K,V>
    
    Returns:
    
    true if the map is empty
    
    See Also:
    
    size()
  - keySet
```
public java.util.Set<K> keySet()
```
    Returns a set view of this map's keys. The set is backed by the map, so changes in one show up in the other. Modifications while an iteration is in progress produce undefined behavior. The set supports removal if entrySet() does, but does not support element addition.
    This implementation creates an AbstractSet, where the iterator wraps the entrySet iterator, size defers to the Map's size, and contains defers to the Map's containsKey. The set is created on first use, and returned on subsequent uses, although since no synchronization occurs, there is a slight possibility of creating two sets.
    
    Specified by:
    
    keySet in interface java.util.Map<K,V>
    
    Returns:
    
    a Set view of the keys
    
    See Also:
    
    Set.iterator(), size(), containsKey(Object), values()
  - put
```
public V put(K key,
             V value)
```
    Associates the given key to the given value (optional operation). If the map already contains the key, its value is replaced. This implementation simply throws an UnsupportedOperationException. Be aware that in a map that permits null values, a null return does not always imply that the mapping was created.
    
    Specified by:
    
    put in interface java.util.Map<K,V>
    
    Parameters:
    
    key - the key to map
    
    value - the value to be mapped
    
    Returns:
    
    the previous value of the key, or null if there was no mapping
    
    Throws:
    
    java.lang.UnsupportedOperationException - if the operation is not supported
    
    java.lang.ClassCastException - if the key or value is of the wrong type
    
    java.lang.IllegalArgumentException - if something about this key or value prevents it from existing in this map
    
    java.lang.NullPointerException - if the map forbids null keys or values
    
    See Also:
    
    containsKey(Object)
  - putAll
```
public void putAll(java.util.Map<? extends K,? extends V> m)
```
    Copies all entries of the given map to this one (optional operation). If the map already contains a key, its value is replaced. This implementation simply iterates over the map's entrySet(), calling put, so it is not supported if puts are not.
    
    Specified by:
    
    putAll in interface java.util.Map<K,V>
    
    Parameters:
    
    m - the mapping to load into this map
    
    Throws:
    
    java.lang.UnsupportedOperationException - if the operation is not supported by this map.
    
    java.lang.ClassCastException - if a key or value is of the wrong type for adding to this map.
    
    java.lang.IllegalArgumentException - if something about a key or value prevents it from existing in this map.
    
    java.lang.NullPointerException - if the map forbids null keys or values.
    
    java.lang.NullPointerException - if m is null.
    
    See Also:
    
    put(Object, Object)
  - remove
```
public V remove(java.lang.Object key)
```
    Removes the mapping for this key if present (optional operation). This implementation iterates over the entrySet searching for a matching key, at which point it calls the iterator's remove method. It returns the result of getValue() on the entry, if found, or null if no entry is found. Note that maps which permit null values may also return null if the key was removed. If the entrySet does not support removal, this will also fail. This is O(n), so many implementations override it for efficiency.
    
    Specified by:
    
    remove in interface java.util.Map<K,V>
    
    Parameters:
    
    key - the key to remove
    
    Returns:
    
    the value the key mapped to, or null if not present. Null may also be returned if null values are allowed in the map and the value of this mapping is null.
    
    Throws:
    
    java.lang.UnsupportedOperationException - if deletion is unsupported
    
    See Also:
    
    Iterator.remove()
  - size
```
public int size()
```
    Returns the number of key-value mappings in the map. If there are more than Integer.MAX_VALUE mappings, return Integer.MAX_VALUE. This is implemented as entrySet().size().
    
    Specified by:
    
    size in interface java.util.Map<K,V>
    
    Returns:
    
    the number of mappings
    
    See Also:
    
    Set.size()
  - toString
```
public java.lang.String toString()
```
    Returns a String representation of this map. This is a listing of the map entries (which are specified in Map.Entry as being getKey() + "=" + getValue()), separated by a comma and space (", "), and surrounded by braces ('{' and '}'). This implementation uses a StringBuffer and iterates over the entrySet to build the String. Note that this can fail with an exception if underlying keys or values complete abruptly in toString().
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a String representation
    
    See Also:
    
    Map.Entry#toString()
  - values
```
public java.util.Collection<V> values()
```
    Returns a collection or bag view of this map's values. The collection is backed by the map, so changes in one show up in the other. Modifications while an iteration is in progress produce undefined behavior. The collection supports removal if entrySet() does, but does not support element addition.
    This implementation creates an AbstractCollection, where the iterator wraps the entrySet iterator, size defers to the Map's size, and contains defers to the Map's containsValue. The collection is created on first use, and returned on subsequent uses, although since no synchronization occurs, there is a slight possibility of creating two collections.
    
    Specified by:
    
    values in interface java.util.Map<K,V>
    
    Returns:
    
    a Collection view of the values
    
    See Also:
    
    Collection.iterator(), size(), containsValue(Object), keySet()
  - equals
```
public static final boolean equals(java.lang.Object o1,
                                   java.lang.Object o2)
```
    Compare two objects according to Collection semantics.
    
    Parameters:
    
    o1 - the first object
    
    o2 - the second object
    
    Returns:
    
    o1 == o2 || (o1 != null && o1.equals(o2))
  - hashCode
```
public static final int hashCode(java.lang.Object o)
```
    Hash an object according to Collection semantics.
    
    Parameters:
    
    o - the object to hash
    
    Returns:
    
    o1 == null ? 0 : o1.hashCode()

Class AbstractMap4D<K,V>

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Map

Constructor Detail

AbstractMap4D

Method Detail

entrySet

clear

clone

containsKey

containsValue

equals

get

hashCode

isEmpty

keySet

put

putAll

remove

size

toString

values

equals

hashCode