Package org.elasticsearch.common.util

Class Maps

java.lang.Object
org.elasticsearch.common.util.Maps
public class Maps extends Object

  • Constructor Summary

    Constructors
    Constructor
    Description
    Maps()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static <K, V> Map<K,V>
    copyMapWithAddedEntry(Map<K,V> map, K key, V value)
    Adds an entry to an immutable map by copying the underlying map and adding the new entry.
    static <K, V> Map<K,V>
    copyMapWithAddedOrReplacedEntry(Map<K,V> map, K key, V value)
    Adds a new entry to or replaces an existing entry in an immutable map by copying the underlying map and adding the new or replacing the existing entry.
    static <K, V> Map<K,V>
    copyMapWithRemovedEntry(Map<K,V> map, K key)
    Remove the specified key from the provided immutable map by copying the underlying map and filtering out the specified key if that key exists.
    static <K, V> boolean
    deepEquals(Map<K,V> left, Map<K,V> right)
    Returns true if the two specified maps are equal to one another.
    static Map<String,Object>
    flatten(Map<String,Object> map, boolean flattenArrays, boolean ordered)
    Returns an array where all internal maps and optionally arrays are flattened into the root map.
    static <K, V> Map<K,V>
    newMapWithExpectedSize(int expectedSize)
    Returns a map with a capacity sufficient to keep expectedSize elements without being resized.
    static <K, V> Map<K,V>
    ofEntries(Collection<Map.Entry<K,V>> entries)
    A convenience method to convert a collection of map entries to a map.
    static <T, K, V> Collector<T,?,Map<K,V>>
    toUnmodifiableOrderedMap(Function<T,? extends K> keyMapper, Function<T,? extends V> valueMapper)
    Returns a Collector that accumulates the input elements into a linked hash map and finishes the resulting set into an unmodifiable map.
    static <T, K, V> Collector<T,?,NavigableMap<K,V>>
    toUnmodifiableSortedMap(Function<T,? extends K> keyMapper, Function<T,? extends V> valueMapper)
    Returns a Collector that accumulates the input elements into a sorted map and finishes the resulting set into an unmodifiable sorted map.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Maps

      public Maps()

  • Method Details

    • copyMapWithAddedEntry

      public static <K, V> Map<K,V> copyMapWithAddedEntry(Map<K,V> map, K key, V value)
      Adds an entry to an immutable map by copying the underlying map and adding the new entry. This method expects there is not already a mapping for the specified key in the map.
      Type Parameters:
      K - the type of the keys in the map
      V - the type of the values in the map
      Parameters:
      map - the immutable map to concatenate the entry to
      key - the key of the new entry
      value - the value of the entry
      Returns:
      an immutable map that contains the items from the specified map and the concatenated entry

    • copyMapWithAddedOrReplacedEntry

      public static <K, V> Map<K,V> copyMapWithAddedOrReplacedEntry(Map<K,V> map, K key, V value)
      Adds a new entry to or replaces an existing entry in an immutable map by copying the underlying map and adding the new or replacing the existing entry.
      Type Parameters:
      K - the type of the keys in the map
      V - the type of the values in the map
      Parameters:
      map - the immutable map to add to or replace in
      key - the key of the new entry
      value - the value of the new entry
      Returns:
      an immutable map that contains the items from the specified map and a mapping from the specified key to the specified value

    • copyMapWithRemovedEntry

      public static <K, V> Map<K,V> copyMapWithRemovedEntry(Map<K,V> map, K key)
      Remove the specified key from the provided immutable map by copying the underlying map and filtering out the specified key if that key exists.
      Type Parameters:
      K - the type of the keys in the map
      V - the type of the values in the map
      Parameters:
      map - the immutable map to remove the key from
      key - the key to be removed
      Returns:
      an immutable map that contains the items from the specified map with the provided key removed

    • ofEntries

      public static <K, V> Map<K,V> ofEntries(Collection<Map.Entry<K,V>> entries)
      A convenience method to convert a collection of map entries to a map. The primary reason this method exists is to have a single source file with an unchecked suppression rather than scattered at the various call sites.
      Type Parameters:
      K - the type of the keys
      V - the type of the values
      Parameters:
      entries - the entries to convert to a map
      Returns:
      an immutable map containing the specified entries

    • deepEquals

      public static <K, V> boolean deepEquals(Map<K,V> left, Map<K,V> right)
      Returns true if the two specified maps are equal to one another. Two maps are considered equal if both represent identical mappings where values are checked with Objects.deepEquals. The primary use case is to check if two maps with array values are equal.
      Parameters:
      left - one map to be tested for equality
      right - the other map to be tested for equality
      Returns:
      true if the two maps are equal

    • flatten

      public static Map<String,Object> flatten(Map<String,Object> map, boolean flattenArrays, boolean ordered)
      Returns an array where all internal maps and optionally arrays are flattened into the root map. For example the map {"foo": {"bar": 1, "baz": [2, 3]}} will become {"foo.bar": 1, "foo.baz.0": 2, "foo.baz.1": 3}. Note that if maps contains keys with "." or numbers it is possible that such keys will be silently overridden. For example the map {"foo": {"bar": 1}, "foo.bar": 2} will become {"foo.bar": 1} or {"foo.bar": 2}.
      Parameters:
      map - - input to be flattened
      flattenArrays - - if false, arrays will be ignored
      ordered - - if true the resulted map will be sorted
      Returns:

    • toUnmodifiableSortedMap

      public static <T, K, V> Collector<T,?,NavigableMap<K,V>> toUnmodifiableSortedMap(Function<T,? extends K> keyMapper, Function<T,? extends V> valueMapper)
      Returns a Collector that accumulates the input elements into a sorted map and finishes the resulting set into an unmodifiable sorted map. The resulting read-only view through the unmodifiable sorted map is a sorted map.
      Type Parameters:
      T - the type of the input elements
      Returns:
      an unmodifiable NavigableMap where the underlying map is sorted

    • toUnmodifiableOrderedMap

      public static <T, K, V> Collector<T,?,Map<K,V>> toUnmodifiableOrderedMap(Function<T,? extends K> keyMapper, Function<T,? extends V> valueMapper)
      Returns a Collector that accumulates the input elements into a linked hash map and finishes the resulting set into an unmodifiable map. The resulting read-only view through the unmodifiable map is a linked hash map.
      Type Parameters:
      T - the type of the input elements
      Returns:
      an unmodifiable Map where the underlying map has a consistent order

    • newMapWithExpectedSize

      public static <K, V> Map<K,V> newMapWithExpectedSize(int expectedSize)
      Returns a map with a capacity sufficient to keep expectedSize elements without being resized.
      Type Parameters:
      K - the key type
      V - the value type
      Parameters:
      expectedSize - the expected amount of elements in the map
      Returns:
      a new pre-sized HashMap