Package myAdapter

Class MapAdapter

java.lang.Object
myAdapter.MapAdapter
All Implemented Interfaces:
HMap
public class MapAdapter extends Object implements HMap
MapAdapter adapts the Hashtable class from Java CLDC 1.1 to the HMap interface. Due to this adaptee this implementation of the map have a restrictions on the keys and values they contain. In fact null keys or values are forbidden.

Therefore it's an Adapter design pattern.

  • Nested Class Summary

    Nested classes/interfaces inherited from interface myAdapter.HMap

    HMap.HEntry

  • Constructor Summary

    Constructors
    Constructor
    Description
    MapAdapter()
    Default constructor with no arguments.
    MapAdapter(HMap map)
    Constructor with map arguments.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Removes all of the mappings from this map.
    boolean
    containsKey(Object key)
    Returns true if this map contains a mapping for the specified key.
    boolean
    containsValue(Object value)
    Returns true if this map maps one or more keys to the specified value.
    HSet
    entrySet()
    Returns a HSet view of the mappings contained in this map.
    boolean
    equals(Object o)
    Compares the specified object with this map for equality.
    Object
    get(Object key)
    Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.
    int
    hashCode()
    Returns the hash code value for this map.
    boolean
    isEmpty()
    Returns true if this map contains no key-value mappings.
    HSet
    keySet()
    Returns a HSet view of the keys contained in this map.
    Object
    put(Object key, Object value)
    Associates the specified value with the specified key in this map (optional operation).
    void
    putAll(HMap t)
    Copies all of the mappings from the specified map to this map (optional operation).
    Object
    remove(Object key)
    Removes the mapping for a key from this map if it is present (optional operation).
    int
    size()
    Returns the number of key-value mappings in this map.
    String
    toString()
    Returns a string representation of this HMap object in the form of a set of entries, enclosed in braces and separated by the ASCII characters " , " (comma and space).
    HCollection
    values()
    Returns a HCollection view of the values contained in this map.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • MapAdapter

      public MapAdapter()
      Default constructor with no arguments.

    • MapAdapter

      public MapAdapter(HMap map)
      Constructor with map arguments. All the elements in the map argument should be included in the map
      Parameters:
      map - to be included in this map

  • Method Details

    • size

      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.
      Specified by:
      size in interface HMap
      Returns:
      the number of key-value mappings in this map

    • isEmpty

      public boolean isEmpty()
      Returns true if this map contains no key-value mappings.
      Specified by:
      isEmpty in interface HMap
      Returns:
      true if this map contains no key-value mappings

    • containsKey

      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.)
      Specified by:
      containsKey in interface HMap
      Parameters:
      key - key whose presence in this map is to be tested
      Returns:
      true if this map contains a mapping for the specified key
      Throws:
      NullPointerException - if the specified key is null (this map does not permit null key).

    • containsValue

      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.
      Specified by:
      containsValue in interface HMap
      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
      Throws:
      NullPointerException - if the specified value is null (this map does not permit null values).

    • get

      public Object 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.

      Specified by:
      get in interface HMap
      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
      Throws:
      NullPointerException - if the specified key is null (this map does not permit null key).

    • put

      public Object put(Object key, Object 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 m.containsKey(k) would return true.)
      Specified by:
      put in interface HMap
      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.)
      Throws:
      NullPointerException - if the specified key or value is null (this map does not permit null key).

    • remove

      public Object 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.

      Specified by:
      remove in interface HMap
      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.
      Throws:
      NullPointerException - if the specified key is null (this map does not permit null key).

    • putAll

      public void putAll(HMap t)
      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(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.
      Specified by:
      putAll in interface HMap
      Parameters:
      m - mappings to be stored in this map
      Throws:
      NullPointerException - 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. (this map does not permit null key).

    • clear

      public void clear()
      Removes all of the mappings from this map. The map will be empty after this call returns.
      Specified by:
      clear in interface HMap

    • keySet

      public HSet keySet()
      Returns a HSet 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 HIterator.remove, HSet.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.
      Specified by:
      keySet in interface HMap
      Returns:
      a set view of the keys contained in this map

    • values

      public HCollection values()
      Returns a HCollection 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 HIterator.remove, HCollection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.
      Specified by:
      values in interface HMap
      Returns:
      a collection view of the values contained in this map

    • entrySet

      public HSet entrySet()
      Returns a HSet 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 HIterator.remove, HSet.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.
      Specified by:
      entrySet in interface HMap
      Returns:
      a set view of the mappings contained in this map

    • equals

      public boolean equals(Object o)
      Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings. More formally, two maps m1 and m2 represent the same mappings if m1.entrySet().equals(m2.entrySet()). This ensures that the equals method works properly across different implementations of the Map interface.
      Specified by:
      equals in interface HMap
      Overrides:
      equals in class Object
      Parameters:
      o - object to be compared for equality with this map
      Returns:
      true if the specified object is equal to this map
      See Also:

    • hashCode

      public int hashCode()
      Returns the hash code value for this map. The hash code of a map is defined to be the sum of the hash codes of each entry in the map's entrySet() view. This ensures that m1.equals(m2) implies that m1.hashCode()==m2.hashCode() for any two maps m1 and m2, as required by the general contract of Object.hashCode().
      Specified by:
      hashCode in interface HMap
      Overrides:
      hashCode in class Object
      Returns:
      the hash code value for this map
      See Also:

    • toString

      public String toString()
      Returns a string representation of this HMap object in the form of a set of entries, enclosed in braces and separated by the ASCII characters " , " (comma and space). Each entry is rendered as the key, an equals sign =, and the associated element, where the toString method is used to convert the key and element to strings.
      Overrides:
      toString in class Object
      Returns:
      a string representation of this map