Package org.jvnet.hk2.component

Class MultiMap<K,​V>

  • Type Parameters:
    K - The key of the multi-map
    V - The types in the multi-map
    All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    public class MultiMap<K,​V>
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable
    Map from a key to multiple values. Order is significant among values, and null values are allowed, although null keys are not.
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static java.lang.String NEWLINE  
      private static long serialVersionUID
      For serialization
      private java.util.Map<K,​java.util.List<V>> store  

    • Constructor Summary

      Constructors 
      Constructor Description
      MultiMap()
      Creates an empty multi-map with default concurrency controls
      MultiMap​(MultiMap<K,​V> base)
      Copy constructor.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private java.util.List<V> _get​(K k)
      Package private (for getting the raw map for direct manipulation by the habitat)
      void add​(K k, V v)
      Adds one more key-value pair.
      MultiMap<K,​V> clone()
      Creates a copy of the map that contains the exact same key and value set.
      boolean contains​(K k1, V k2)
      Checks if the map contains the given key(s), also extending the search to including the sub collection.
      boolean containsKey​(K k)
      Checks if the map contains the given key.
      java.util.Set<java.util.Map.Entry<K,​java.util.List<V>>> entrySet()
      Lists up all entries.
      boolean equals​(java.lang.Object another)  
      java.util.List<V> get​(K k)
      Returns the elements indexed by the provided key
      private V getFirst​(K k)  
      V getOne​(K k)
      Gets the first value if any, or null.
      int hashCode()  
      java.util.Set<K> keySet()
      Returns the set of keys associated with this MultiMap
      void mergeAll​(MultiMap<K,​V> another)
      This method merges all of the keys and values from another MultiMap into this MultiMap.
      private java.util.List<V> newList​(java.util.Collection<? extends V> initialVals)
      Creates an optionally populated list to be used as an entry in the map.
      java.util.List<V> remove​(K key)
      Removes an key value from the map
      boolean remove​(K key, V entry)
      Removes an key value pair from the map.
      void set​(K k, java.util.Collection<? extends V> v)
      Replaces all the existing values associated with the key by the given value.
      void set​(K k, V v)
      Replaces all the existing values associated with the key by the given single value.
      int size()
      Returns the size of the map.
      java.lang.String toCommaSeparatedString()  
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • serialVersionUID

        private static final long serialVersionUID
        For serialization
        See Also:
        Constant Field Values

      • store

        private final java.util.Map<K,​java.util.List<V>> store

      • NEWLINE

        private static final java.lang.String NEWLINE

    • Constructor Detail

      • MultiMap

        public MultiMap()
        Creates an empty multi-map with default concurrency controls

      • MultiMap

        public MultiMap​(MultiMap<K,​V> base)
        Copy constructor.
        Parameters:
        base - map to copy

    • Method Detail

      • newList

        private java.util.List<V> newList​(java.util.Collection<? extends V> initialVals)
        Creates an optionally populated list to be used as an entry in the map.
        Parameters:
        initialVal -
        Returns:

      • keySet

        public java.util.Set<K> keySet()
        Returns the set of keys associated with this MultiMap
        Returns:
        The set of keys currently available in this MultiMap. Will not return null, but may return a Set of lenght zero

      • add

        public final void add​(K k,
                      V v)
        Adds one more key-value pair.
        Parameters:
        k - key to store the entry under
        v - value to store in the k's values.

      • set

        public void set​(K k,
                java.util.Collection<? extends V> v)
        Replaces all the existing values associated with the key by the given value. If v is empty the key k will be removed from the MultiMap.
        Parameters:
        k - key for the values
        v - Can be null or empty.

      • set

        public void set​(K k,
                V v)
        Replaces all the existing values associated with the key by the given single value.
        Parameters:
        k - key for the values
        v - singleton value for k key

        This is short for set(k,Collections.singleton(v))

      • get

        public final java.util.List<V> get​(K k)
        Returns the elements indexed by the provided key
        Parameters:
        k - key for the values
        Returns:
        Can be empty but never null. Read-only.

      • mergeAll

        public void mergeAll​(MultiMap<K,​V> another)
        This method merges all of the keys and values from another MultiMap into this MultiMap. If a key/value pair is found in both MultiMaps it is not re-added to this MultiMap, but is instead discarded
        Parameters:
        another - The MultiMap from which to add values to this MultiMap. If null this method does nothing

      • _get

        private final java.util.List<V> _get​(K k)
        Package private (for getting the raw map for direct manipulation by the habitat)
        Parameters:
        k - the key
        Returns:

      • containsKey

        public boolean containsKey​(K k)
        Checks if the map contains the given key.
        Parameters:
        k - key to test
        Returns:
        true if the map contains at least one element for this key

      • contains

        public boolean contains​(K k1,
                        V k2)
        Checks if the map contains the given key(s), also extending the search to including the sub collection.
        Parameters:
        k1 - key from top collection
        k2 - key (value) from inner collection
        Returns:
        true if the map contains at least one element for these keys

      • remove

        public java.util.List<V> remove​(K key)
        Removes an key value from the map
        Parameters:
        key - key to be removed
        Returns:
        the value stored under this key or null if there was none

      • remove

        public boolean remove​(K key,
                      V entry)
        Removes an key value pair from the map. If the list of entries for that key is empty after the remove it will be removed from the set of keys
        Parameters:
        key - key to be removed
        entry - the entry to be removed from the key'ed list
        Returns:
        true if there was none that was deleted

      • getOne

        public V getOne​(K k)
        Gets the first value if any, or null.

        This is useful when you know the given key only has one value and you'd like to get to that value.

        Parameters:
        k - key for the values
        Returns:
        null if the key has no values or it has a value but the value is null.

      • getFirst

        private V getFirst​(K k)

      • entrySet

        public java.util.Set<java.util.Map.Entry<K,​java.util.List<V>>> entrySet()
        Lists up all entries.
        Returns:
        a Set of Map.Entry of entries

      • toCommaSeparatedString

        public java.lang.String toCommaSeparatedString()
        Returns:
        the map as "key=value1,key=value2,...."

      • clone

        public MultiMap<K,​V> clone()
                          throws java.lang.CloneNotSupportedException
        Creates a copy of the map that contains the exact same key and value set. Keys and values won't cloned.
        Overrides:
        clone in class java.lang.Object
        Throws:
        java.lang.CloneNotSupportedException

      • size

        public int size()
        Returns the size of the map. This returns the numbers of keys in the map, not the number of values
        Returns:
        integer or 0 if the map is empty

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • equals

        public boolean equals​(java.lang.Object another)
        Overrides:
        equals in class java.lang.Object

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object