Package org.eclipse.collections.api.map

Interface MutableMap<K,V>

All Superinterfaces:
Cloneable, InternalIterable<V>, Iterable<V>, Map<K,V>, MapIterable<K,V>, MutableMapIterable<K,V>, RichIterable<V>, UnsortedMapIterable<K,V>
All Known Subinterfaces:
ConcurrentMutableMap<K,V>, FixedSizeMap<K,V>
All Known Implementing Classes:
AbstractMutableMap, ConcurrentHashMap, ConcurrentHashMapUnsafe, ConcurrentMutableHashMap, MapAdapter, SynchronizedMutableMap, UnifiedMap, UnifiedMapWithHashingStrategy, UnmodifiableMutableMap
public interface MutableMap<K,V> extends MutableMapIterable<K,V>, UnsortedMapIterable<K,V>, Cloneable
A MutableMap is similar to a JCF Map but adds additional useful internal iterator methods. The MutableMap interface additionally implements some of the methods in the Smalltalk Dictionary protocol.

  • Method Details

    • collectKeysAndValues

      <E> MutableMap<K,V> collectKeysAndValues(Iterable<E> iterable, Function<? super E,? extends K> keyFunction, Function<? super E,? extends V> valueFunction)
      Adds all the entries derived from iterable to this. The key and value for each entry is determined by applying the keyFunction and valueFunction to each item in collection. Any entry in map that has the same key as an entry in this will have its value replaced by that in map.

    • newEmpty

      MutableMap<K,V> newEmpty()
      Description copied from interface: MutableMapIterable
      Creates a new instance of the same type, using the default capacity and growth parameters.
      Specified by:
      newEmpty in interface MutableMapIterable<K,V>

    • clone

      MutableMap<K,V> clone()

    • asUnmodifiable

      MutableMap<K,V> asUnmodifiable()
      Description copied from interface: MutableMapIterable
      Returns an unmodifiable view of this map. This is the equivalent of using Collections.unmodifiableMap(this) only with a return type that supports the full iteration protocols available on MutableMapIterable. Methods which would mutate the underlying map will throw UnsupportedOperationExceptions.
      Specified by:
      asUnmodifiable in interface MutableMapIterable<K,V>
      Returns:
      an unmodifiable view of this map.
      See Also:

    • asSynchronized

      MutableMap<K,V> asSynchronized()
      Description copied from interface: MutableMapIterable
      Returns a synchronized wrapper backed by this map. This is the equivalent of calling Collections.synchronizedMap(this) only with the more feature rich return type of MutableMapIterable.

      The preferred way of iterating over a synchronized map is to use the forEachKey(), forEachValue() and forEachKeyValue() methods which are properly synchronized internally. 

        MutableMap synchedMap = map.asSynchronized();

  synchedMap.forEachKey(key -> ... );
  synchedMap.forEachValue(value -> ... );
  synchedMap.forEachKeyValue((key, value) -> ... );

      If you want to iterate imperatively over the keySet(), values(), or entrySet(), you will need to protect the iteration by wrapping the code in a synchronized block on the map.

      Specified by:
      asSynchronized in interface MutableMapIterable<K,V>
      See Also:

    • flip

      MutableSetMultimap<V,K> flip()
      Description copied from interface: MapIterable
      Given a map from Domain -> Range return a multimap from Range -> Domain. We chose the name 'flip' rather than 'invert' or 'transpose' since this method does not have the property of applying twice returns the original.

      Since the keys in the input are unique, the values in the output are unique, so the return type should be a SetMultimap. However since SetMultimap and SortedSetMultimap don't inherit from one another, SetMultimap here does not allow SortedMapIterable to have a SortedSetMultimap return. Thus we compromise and call this Multimap, even though all implementations will be a SetMultimap or SortedSetMultimap.

      Specified by:
      flip in interface MapIterable<K,V>
      Specified by:
      flip in interface MutableMapIterable<K,V>
      Specified by:
      flip in interface UnsortedMapIterable<K,V>

    • select

      MutableMap<K,V> select(Predicate2<? super K,? super V> predicate)
      Description copied from interface: MapIterable
      For each key and value of the map the predicate is evaluated, if the result of the evaluation is true, that key and value are returned in a new map. 
       MapIterable<City, Person> selected =
     peopleByCity.select((city, person) -> city.getName().equals("Anytown") && person.getLastName().equals("Smith"));
      Specified by:
      select in interface MapIterable<K,V>
      Specified by:
      select in interface MutableMapIterable<K,V>
      Specified by:
      select in interface UnsortedMapIterable<K,V>

    • reject

      MutableMap<K,V> reject(Predicate2<? super K,? super V> predicate)
      Description copied from interface: MapIterable
      For each key and value of the map the predicate is evaluated, if the result of the evaluation is false, that key and value are returned in a new map. 
       MapIterable<City, Person> rejected =
     peopleByCity.reject((city, person) -> city.getName().equals("Anytown") && person.getLastName().equals("Smith"));
      Specified by:
      reject in interface MapIterable<K,V>
      Specified by:
      reject in interface MutableMapIterable<K,V>
      Specified by:
      reject in interface UnsortedMapIterable<K,V>

    • collectValues

      <R> MutableMap<K,R> collectValues(Function2<? super K,? super V,? extends R> function)
      Description copied from interface: MapIterable
      For each key and value of the map the function is evaluated. The results of these evaluations are returned in a new map. The map returned will use the values projected from the function rather than the original values. 
       MapIterable<City, String> collected =
     peopleByCity.collectValues((City city, Person person) -> person.getFirstName() + " " + person.getLastName());
      Specified by:
      collectValues in interface MapIterable<K,V>
      Specified by:
      collectValues in interface MutableMapIterable<K,V>
      Specified by:
      collectValues in interface UnsortedMapIterable<K,V>

    • collect

      <K2, V2> MutableMap<K2,V2> collect(Function2<? super K,? super V,Pair<K2,V2>> function)
      Description copied from interface: MapIterable
      For each key and value of the map the function is evaluated. The results of these evaluations are returned in a new map. The map returned will use the values projected from the function rather than the original values. 
       MapIterable<String, String> collected =
     peopleByCity.collect((City city, Person person) -> Pair.of(city.getCountry(), person.getAddress().getCity()));
      Specified by:
      collect in interface MapIterable<K,V>
      Specified by:
      collect in interface MutableMapIterable<K,V>
      Specified by:
      collect in interface UnsortedMapIterable<K,V>

    • tap

      MutableMap<K,V> tap(Procedure<? super V> procedure)
      Description copied from interface: MapIterable
      Executes the Procedure for each value of the map and returns this. 
       return peopleByCity.tap(person -> LOGGER.info(person.getName()));
      Specified by:
      tap in interface MapIterable<K,V>
      Specified by:
      tap in interface MutableMapIterable<K,V>
      Specified by:
      tap in interface RichIterable<K>
      Specified by:
      tap in interface UnsortedMapIterable<K,V>
      See Also:

    • select

      MutableBag<V> select(Predicate<? super V> predicate)
      Description copied from interface: RichIterable
      Returns all elements of the source collection that return true when evaluating the predicate. This method is also commonly called filter.

      Example using a Java 8 lambda expression: 

       RichIterable<Person> selected =
     people.select(person -> person.getAddress().getCity().equals("London"));

      Example using an anonymous inner class: 

       RichIterable<Person> selected =
     people.select(new Predicate<Person>()
     {
         public boolean accept(Person person)
         {
             return person.getAddress().getCity().equals("London");
         }
     });
      Specified by:
      select in interface MutableMapIterable<K,V>
      Specified by:
      select in interface RichIterable<K>
      Specified by:
      select in interface UnsortedMapIterable<K,V>

    • selectWith

      <P> MutableBag<V> selectWith(Predicate2<? super V,? super P> predicate, P parameter)
      Description copied from interface: RichIterable
      Similar to RichIterable.select(Predicate), except with an evaluation parameter for the second generic argument in Predicate2.

      E.g. return a Collection of Person elements where the person has an age greater than or equal to 18 years

      Example using a Java 8 lambda expression: 

       RichIterable<Person> selected =
     people.selectWith((Person person, Integer age) -> person.getAge()>= age, Integer.valueOf(18));

      Example using an anonymous inner class: 

       RichIterable<Person> selected =
     people.selectWith(new Predicate2<Person, Integer>()
     {
         public boolean accept(Person person, Integer age)
         {
             return person.getAge()>= age;
         }
     }, Integer.valueOf(18));
      Specified by:
      selectWith in interface MutableMapIterable<K,V>
      Specified by:
      selectWith in interface RichIterable<K>
      Specified by:
      selectWith in interface UnsortedMapIterable<K,V>
      Parameters:
      predicate - a Predicate2 to use as the select criteria
      parameter - a parameter to pass in for evaluation of the second argument P in predicate
      See Also:

    • reject

      MutableBag<V> reject(Predicate<? super V> predicate)
      Description copied from interface: RichIterable
      Returns all elements of the source collection that return false when evaluating of the predicate. This method is also sometimes called filterNot and is the equivalent of calling iterable.select(Predicates.not(predicate)).

      Example using a Java 8 lambda expression: 

       RichIterable<Person> rejected =
     people.reject(person -> person.person.getLastName().equals("Smith"));

      Example using an anonymous inner class: 

       RichIterable<Person> rejected =
     people.reject(new Predicate<Person>()
     {
         public boolean accept(Person person)
         {
             return person.person.getLastName().equals("Smith");
         }
     });
      Specified by:
      reject in interface MutableMapIterable<K,V>
      Specified by:
      reject in interface RichIterable<K>
      Specified by:
      reject in interface UnsortedMapIterable<K,V>
      Parameters:
      predicate - a Predicate to use as the reject criteria
      Returns:
      a RichIterable that contains elements that cause Predicate.accept(Object) method to evaluate to false

    • rejectWith

      <P> MutableBag<V> rejectWith(Predicate2<? super V,? super P> predicate, P parameter)
      Description copied from interface: RichIterable
      Similar to RichIterable.reject(Predicate), except with an evaluation parameter for the second generic argument in Predicate2.

      E.g. return a Collection of Person elements where the person has an age greater than or equal to 18 years

      Example using a Java 8 lambda expression: 

       RichIterable<Person> rejected =
     people.rejectWith((Person person, Integer age) -> person.getAge() < age, Integer.valueOf(18));

      Example using an anonymous inner class: 

       MutableList<Person> rejected =
     people.rejectWith(new Predicate2<Person, Integer>()
     {
         public boolean accept(Person person, Integer age)
         {
             return person.getAge() < age;
         }
     }, Integer.valueOf(18));
      Specified by:
      rejectWith in interface MutableMapIterable<K,V>
      Specified by:
      rejectWith in interface RichIterable<K>
      Specified by:
      rejectWith in interface UnsortedMapIterable<K,V>
      Parameters:
      predicate - a Predicate2 to use as the select criteria
      parameter - a parameter to pass in for evaluation of the second argument P in predicate
      See Also:

    • partition

      PartitionMutableBag<V> partition(Predicate<? super V> predicate)
      Description copied from interface: RichIterable
      Filters a collection into a PartitionedIterable based on the evaluation of the predicate.

      Example using a Java 8 lambda expression: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partition(person -> person.getAddress().getState().getName().equals("New York"));

      Example using an anonymous inner class: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partition(new Predicate<Person>()
     {
         public boolean accept(Person person)
         {
             return person.getAddress().getState().getName().equals("New York");
         }
     });
      Specified by:
      partition in interface MutableMapIterable<K,V>
      Specified by:
      partition in interface RichIterable<K>
      Specified by:
      partition in interface UnsortedMapIterable<K,V>

    • partitionWith

      <P> PartitionMutableBag<V> partitionWith(Predicate2<? super V,? super P> predicate, P parameter)
      Description copied from interface: RichIterable
      Filters a collection into a PartitionIterable based on the evaluation of the predicate.

      Example using a Java 8 lambda expression: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partitionWith((Person person, String state) -> person.getAddress().getState().getName().equals(state), "New York");

      Example using an anonymous inner class: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partitionWith(new Predicate2<Person, String>()
     {
         public boolean accept(Person person, String state)
         {
             return person.getAddress().getState().getName().equals(state);
         }
     }, "New York");
      Specified by:
      partitionWith in interface RichIterable<K>
      Specified by:
      partitionWith in interface UnsortedMapIterable<K,V>

    • selectInstancesOf

      <S> MutableBag<S> selectInstancesOf(Class<S> clazz)
      Description copied from interface: RichIterable
      Returns all elements of the source collection that are instances of the Class clazz. 
       RichIterable<Integer> integers =
     List.mutable.with(new Integer(0), new Long(0L), new Double(0.0)).selectInstancesOf(Integer.class);
      Specified by:
      selectInstancesOf in interface MutableMapIterable<K,V>
      Specified by:
      selectInstancesOf in interface RichIterable<K>
      Specified by:
      selectInstancesOf in interface UnsortedMapIterable<K,V>

    • collect

      <R> MutableBag<R> collect(Function<? super V,? extends R> function)
      Description copied from interface: RichIterable
      Returns a new collection with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       RichIterable<String> names =
     people.collect(person -> person.getFirstName() + " " + person.getLastName());

      Example using an anonymous inner class: 

       RichIterable<String> names =
     people.collect(new Function<Person, String>()
     {
         public String valueOf(Person person)
         {
             return person.getFirstName() + " " + person.getLastName();
         }
     });
      Specified by:
      collect in interface RichIterable<K>
      Specified by:
      collect in interface UnsortedMapIterable<K,V>

    • collectWith

      <P, V1> MutableBag<V1> collectWith(Function2<? super V,? super P,? extends V1> function, P parameter)
      Description copied from interface: RichIterable
      Same as RichIterable.collect(Function) with a Function2 and specified parameter which is passed to the block.

      Example using a Java 8 lambda expression: 

       RichIterable<Integer> integers =
     Lists.mutable.with(1, 2, 3).collectWith((each, parameter) -> each + parameter, Integer.valueOf(1));

      Example using an anonymous inner class: 

       Function2<Integer, Integer, Integer> addParameterFunction =
     new Function2<Integer, Integer, Integer>()
     {
         public Integer value(Integer each, Integer parameter)
         {
             return each + parameter;
         }
     };
 RichIterable<Integer> integers =
     Lists.mutable.with(1, 2, 3).collectWith(addParameterFunction, Integer.valueOf(1));
      Specified by:
      collectWith in interface RichIterable<K>
      Specified by:
      collectWith in interface UnsortedMapIterable<K,V>
      Parameters:
      function - A Function2 to use as the collect transformation function
      parameter - A parameter to pass in for evaluation of the second argument P in function
      Returns:
      A new RichIterable that contains the transformed elements returned by Function2.value(Object, Object)
      See Also:

    • collectBoolean

      MutableBooleanBag collectBoolean(BooleanFunction<? super V> booleanFunction)
      Description copied from interface: RichIterable
      Returns a new primitive boolean iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       BooleanIterable licenses =
     people.collectBoolean(person -> person.hasDrivingLicense());

      Example using an anonymous inner class: 

       BooleanIterable licenses =
     people.collectBoolean(new BooleanFunction<Person>()
     {
         public boolean booleanValueOf(Person person)
         {
             return person.hasDrivingLicense();
         }
     });
      Specified by:
      collectBoolean in interface RichIterable<K>
      Specified by:
      collectBoolean in interface UnsortedMapIterable<K,V>

    • collectByte

      MutableByteBag collectByte(ByteFunction<? super V> byteFunction)
      Description copied from interface: RichIterable
      Returns a new primitive byte iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       ByteIterable bytes =
     people.collectByte(person -> person.getCode());

      Example using an anonymous inner class: 

       ByteIterable bytes =
     people.collectByte(new ByteFunction<Person>()
     {
         public byte byteValueOf(Person person)
         {
             return person.getCode();
         }
     });
      Specified by:
      collectByte in interface RichIterable<K>
      Specified by:
      collectByte in interface UnsortedMapIterable<K,V>

    • collectChar

      MutableCharBag collectChar(CharFunction<? super V> charFunction)
      Description copied from interface: RichIterable
      Returns a new primitive char iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       CharIterable chars =
     people.collectChar(person -> person.getMiddleInitial());

      Example using an anonymous inner class: 

       CharIterable chars =
     people.collectChar(new CharFunction<Person>()
     {
         public char charValueOf(Person person)
         {
             return person.getMiddleInitial();
         }
     });
      Specified by:
      collectChar in interface RichIterable<K>
      Specified by:
      collectChar in interface UnsortedMapIterable<K,V>

    • collectDouble

      MutableDoubleBag collectDouble(DoubleFunction<? super V> doubleFunction)
      Description copied from interface: RichIterable
      Returns a new primitive double iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       DoubleIterable doubles =
     people.collectDouble(person -> person.getMilesFromNorthPole());

      Example using an anonymous inner class: 

       DoubleIterable doubles =
     people.collectDouble(new DoubleFunction<Person>()
     {
         public double doubleValueOf(Person person)
         {
             return person.getMilesFromNorthPole();
         }
     });
      Specified by:
      collectDouble in interface RichIterable<K>
      Specified by:
      collectDouble in interface UnsortedMapIterable<K,V>

    • collectFloat

      MutableFloatBag collectFloat(FloatFunction<? super V> floatFunction)
      Description copied from interface: RichIterable
      Returns a new primitive float iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       FloatIterable floats =
     people.collectFloat(person -> person.getHeightInInches());

      Example using an anonymous inner class: 

       FloatIterable floats =
     people.collectFloat(new FloatFunction<Person>()
     {
         public float floatValueOf(Person person)
         {
             return person.getHeightInInches();
         }
     });
      Specified by:
      collectFloat in interface RichIterable<K>
      Specified by:
      collectFloat in interface UnsortedMapIterable<K,V>

    • collectInt

      MutableIntBag collectInt(IntFunction<? super V> intFunction)
      Description copied from interface: RichIterable
      Returns a new primitive int iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       IntIterable ints =
     people.collectInt(person -> person.getAge());

      Example using an anonymous inner class: 

       IntIterable ints =
     people.collectInt(new IntFunction<Person>()
     {
         public int intValueOf(Person person)
         {
             return person.getAge();
         }
     });
      Specified by:
      collectInt in interface RichIterable<K>
      Specified by:
      collectInt in interface UnsortedMapIterable<K,V>

    • collectLong

      MutableLongBag collectLong(LongFunction<? super V> longFunction)
      Description copied from interface: RichIterable
      Returns a new primitive long iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       LongIterable longs =
     people.collectLong(person -> person.getGuid());

      Example using an anonymous inner class: 

       LongIterable longs =
     people.collectLong(new LongFunction<Person>()
     {
         public long longValueOf(Person person)
         {
             return person.getGuid();
         }
     });
      Specified by:
      collectLong in interface RichIterable<K>
      Specified by:
      collectLong in interface UnsortedMapIterable<K,V>

    • collectShort

      MutableShortBag collectShort(ShortFunction<? super V> shortFunction)
      Description copied from interface: RichIterable
      Returns a new primitive short iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       ShortIterable shorts =
     people.collectShort(person -> person.getNumberOfJunkMailItemsReceivedPerMonth());

      Example using an anonymous inner class: 

       ShortIterable shorts =
     people.collectShort(new ShortFunction<Person>()
     {
         public short shortValueOf(Person person)
         {
             return person.getNumberOfJunkMailItemsReceivedPerMonth();
         }
     });
      Specified by:
      collectShort in interface RichIterable<K>
      Specified by:
      collectShort in interface UnsortedMapIterable<K,V>

    • collectIf

      <R> MutableBag<R> collectIf(Predicate<? super V> predicate, Function<? super V,? extends R> function)
      Description copied from interface: RichIterable
      Returns a new collection with the results of applying the specified function on each element of the source collection, but only for those elements which return true upon evaluation of the predicate. This is the the optimized equivalent of calling iterable.select(predicate).collect(function).

      Example using a Java 8 lambda and method reference: 

       RichIterable<String> strings = Lists.mutable.with(1, 2, 3).collectIf(e -> e != null, Object::toString);

      Example using Predicates factory: 

       RichIterable<String> strings = Lists.mutable.with(1, 2, 3).collectIf(Predicates.notNull(), Functions.getToString());
      Specified by:
      collectIf in interface RichIterable<K>
      Specified by:
      collectIf in interface UnsortedMapIterable<K,V>

    • flatCollect

      <R> MutableBag<R> flatCollect(Function<? super V,? extends Iterable<R>> function)
      Description copied from interface: RichIterable
      flatCollect is a special case of RichIterable.collect(Function). With collect, when the Function returns a collection, the result is a collection of collections. flatCollect outputs a single "flattened" collection instead. This method is commonly called flatMap.

      Consider the following example where we have a Person class, and each Person has a list of Address objects. Take the following Function: 

       Function<Person, List<Address>> addressFunction = Person::getAddresses;
 RichIterable<Person> people = ...;
      Using collect returns a collection of collections of addresses. 
       RichIterable<List<Address>> addresses = people.collect(addressFunction);
      Using flatCollect returns a single flattened list of addresses. 
       RichIterable<Address> addresses = people.flatCollect(addressFunction);
      Specified by:
      flatCollect in interface RichIterable<K>
      Specified by:
      flatCollect in interface UnsortedMapIterable<K,V>
      Parameters:
      function - The Function to apply
      Returns:
      a new flattened collection produced by applying the given function

    • flatCollectWith

      default <P, R> MutableBag<R> flatCollectWith(Function2<? super V,? super P,? extends Iterable<R>> function, P parameter)
      Specified by:
      flatCollectWith in interface RichIterable<K>
      Specified by:
      flatCollectWith in interface UnsortedMapIterable<K,V>
      Since:
      9.2

    • zip

      @Deprecated <S> MutableBag<Pair<V,S>> zip(Iterable<S> that)
      Deprecated.
      in 6.0. Use OrderedIterable.zip(Iterable) instead.
      Description copied from interface: RichIterable
      Returns a RichIterable formed from this RichIterable and another RichIterable by combining corresponding elements in pairs. If one of the two RichIterables is longer than the other, its remaining elements are ignored.
      Specified by:
      zip in interface MutableMapIterable<K,V>
      Specified by:
      zip in interface RichIterable<K>
      Specified by:
      zip in interface UnsortedMapIterable<K,V>
      Type Parameters:
      S - the type of the second half of the returned pairs
      Parameters:
      that - The RichIterable providing the second half of each result pair
      Returns:
      A new RichIterable containing pairs consisting of corresponding elements of this RichIterable and that. The length of the returned RichIterable is the minimum of the lengths of this RichIterable and that.

    • zipWithIndex

      @Deprecated MutableSet<Pair<V,Integer>> zipWithIndex()
      Deprecated.
      in 6.0. Use OrderedIterable.zipWithIndex() instead.
      Description copied from interface: RichIterable
      Zips this RichIterable with its indices.
      Specified by:
      zipWithIndex in interface MutableMapIterable<K,V>
      Specified by:
      zipWithIndex in interface RichIterable<K>
      Specified by:
      zipWithIndex in interface UnsortedMapIterable<K,V>
      Returns:
      A new RichIterable containing pairs consisting of all elements of this RichIterable paired with their index. Indices start at 0.
      See Also:

    • groupBy

      <VV> MutableBagMultimap<VV,V> groupBy(Function<? super V,? extends VV> function)
      Description copied from interface: RichIterable
      For each element of the iterable, the function is evaluated and the results of these evaluations are collected into a new multimap, where the transformed value is the key and the original values are added to the same (or similar) species of collection as the source iterable.

      Example using a Java 8 method reference: 

       Multimap<String, Person> peopleByLastName =
     people.groupBy(Person::getLastName);

      Example using an anonymous inner class: 

       Multimap<String, Person> peopleByLastName =
     people.groupBy(new Function<Person, String>()
     {
         public String valueOf(Person person)
         {
             return person.getLastName();
         }
     });
      Specified by:
      groupBy in interface MutableMapIterable<K,V>
      Specified by:
      groupBy in interface RichIterable<K>
      Specified by:
      groupBy in interface UnsortedMapIterable<K,V>

    • groupByEach

      <VV> MutableBagMultimap<VV,V> groupByEach(Function<? super V,? extends Iterable<VV>> function)
      Description copied from interface: RichIterable
      Similar to RichIterable.groupBy(Function), except the result of evaluating function will return a collection of keys for each value.
      Specified by:
      groupByEach in interface MutableMapIterable<K,V>
      Specified by:
      groupByEach in interface RichIterable<K>
      Specified by:
      groupByEach in interface UnsortedMapIterable<K,V>

    • groupByUniqueKey

      default <V1> MutableMap<V1,V> groupByUniqueKey(Function<? super V,? extends V1> function)
      Description copied from interface: RichIterable
      For each element of the iterable, the function is evaluated and he results of these evaluations are collected into a new map, where the transformed value is the key. The generated keys must each be unique, or else an exception is thrown.
      Specified by:
      groupByUniqueKey in interface MutableMapIterable<K,V>
      Specified by:
      groupByUniqueKey in interface RichIterable<K>
      Specified by:
      groupByUniqueKey in interface UnsortedMapIterable<K,V>
      See Also:

    • aggregateInPlaceBy

      default <KK, VV> MutableMap<KK,VV> aggregateInPlaceBy(Function<? super V,? extends KK> groupBy, Function0<? extends VV> zeroValueFactory, Procedure2<? super VV,? super V> mutatingAggregator)
      Description copied from interface: RichIterable
      Applies an aggregate procedure over the iterable grouping results into a Map based on the specific groupBy function. Aggregate results are required to be mutable as they will be changed in place by the procedure. A second function specifies the initial "zero" aggregate value to work with (i.e. new AtomicInteger(0)).
      Specified by:
      aggregateInPlaceBy in interface MutableMapIterable<K,V>
      Specified by:
      aggregateInPlaceBy in interface RichIterable<K>

    • aggregateBy

      default <KK, VV> MutableMap<KK,VV> aggregateBy(Function<? super V,? extends KK> groupBy, Function0<? extends VV> zeroValueFactory, Function2<? super VV,? super V,? extends VV> nonMutatingAggregator)
      Description copied from interface: RichIterable
      Applies an aggregate function over the iterable grouping results into a map based on the specific groupBy function. Aggregate results are allowed to be immutable as they will be replaced in place in the map. A second function specifies the initial "zero" aggregate value to work with (i.e. Integer.valueOf(0)).
      Specified by:
      aggregateBy in interface MutableMapIterable<K,V>
      Specified by:
      aggregateBy in interface RichIterable<K>

    • aggregateBy

      default <K1, V1, V2> MutableMap<K1,V2> aggregateBy(Function<? super K,? extends K1> keyFunction, Function<? super V,? extends V1> valueFunction, Function0<? extends V2> zeroValueFactory, Function2<? super V2,? super V1,? extends V2> nonMutatingAggregator)
      Description copied from interface: MapIterable
      Applies an aggregate function over the map grouping results into a map based on the specific key and value groupBy functions. Aggregate results are allowed to be immutable as they will be replaced in place in the map. A second function specifies the initial "zero" aggregate value to work with. 
       MapIterable<String, Interval> map = Maps.mutable.with("oneToFive", Interval.fromTo(1, 5), "sixToNine", Interval.fromTo(6, 9));

 MapIterable<String, Long> result = map.aggregateBy(
         eachKey -> {
             return eachKey.equals("oneToFive")  ? "lessThanSix" : "greaterOrEqualsToSix";
         },
         each -> each.sumOfInt(Integer::intValue),
         () -> 0L,
         (argument1, argument2) -> argument1 + argument2);

 MapIterable<String, Long> expected =
         Maps.mutable.with("lessThanSix", Interval.fromTo(1, 5).sumOfInt(Integer::intValue),
                 "greaterOrEqualsToSix", Interval.fromTo(6, 9).sumOfInt(Integer::intValue));
 Assert.assertEquals(expected, result);
      Specified by:
      aggregateBy in interface MapIterable<K,V>
      Specified by:
      aggregateBy in interface MutableMapIterable<K,V>

    • flipUniqueValues

      MutableMap<V,K> flipUniqueValues()
      Description copied from interface: MapIterable
      Return the MapIterable that is obtained by flipping the direction of this map and making the associations from value to key. 
           MapIterable<Integer, String> map = this.newMapWithKeysValues(1, "1", 2, "2", 3, "3");
     MapIterable<String, Integer> result = map.flipUniqueValues();
     Assert.assertTrue(result.equals(UnifiedMap.newWithKeysValues("1", 1, "2", 2, "3", 3)));
      Specified by:
      flipUniqueValues in interface MapIterable<K,V>
      Specified by:
      flipUniqueValues in interface MutableMapIterable<K,V>
      Specified by:
      flipUniqueValues in interface UnsortedMapIterable<K,V>

    • withKeyValue

      MutableMap<K,V> withKeyValue(K key, V value)
      Description copied from interface: MutableMapIterable
      This method allows mutable, fixed size, and immutable maps the ability to add elements to their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original plus the additional key and value. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken: 
       map = map.withKeyValue("new key", "new value");
      In the case of FixedSizeMap, a new instance will be returned by withKeyValue, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling put on themselves.
      Specified by:
      withKeyValue in interface MutableMapIterable<K,V>
      See Also:

    • withMap

      default MutableMap<K,V> withMap(Map<? extends K,? extends V> map)
      Description copied from interface: MutableMapIterable
      Similar to Map.putAll(Map), but returns this instead of void
      Specified by:
      withMap in interface MutableMapIterable<K,V>
      See Also:

    • withMapIterable

      default MutableMap<K,V> withMapIterable(MapIterable<? extends K,? extends V> mapIterable)
      Specified by:
      withMapIterable in interface MutableMapIterable<K,V>

    • withAllKeyValues

      MutableMap<K,V> withAllKeyValues(Iterable<? extends Pair<? extends K,? extends V>> keyValues)
      Description copied from interface: MutableMapIterable
      This method allows mutable, fixed size, and immutable maps the ability to add elements to their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original plus all of the additional keys and values. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken: 
       map = map.withAllKeyValues(FastList.newListWith(PairImpl.of("new key", "new value")));
      In the case of FixedSizeMap, a new instance will be returned by withAllKeyValues, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling put on themselves.
      Specified by:
      withAllKeyValues in interface MutableMapIterable<K,V>
      See Also:

    • withAllKeyValueArguments

      MutableMap<K,V> withAllKeyValueArguments(Pair<? extends K,? extends V>... keyValuePairs)
      Description copied from interface: MutableMapIterable
      Convenience var-args version of withAllKeyValues
      Specified by:
      withAllKeyValueArguments in interface MutableMapIterable<K,V>
      See Also:

    • withoutKey

      MutableMap<K,V> withoutKey(K key)
      Description copied from interface: MutableMapIterable
      This method allows mutable, fixed size, and immutable maps the ability to remove elements from their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original minus the key and value to be removed. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken: 
       map = map.withoutKey("key");
      In the case of FixedSizeMap, a new instance will be returned by withoutKey, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling remove on themselves.
      Specified by:
      withoutKey in interface MutableMapIterable<K,V>
      See Also:

    • withoutAllKeys

      MutableMap<K,V> withoutAllKeys(Iterable<? extends K> keys)
      Description copied from interface: MutableMapIterable
      This method allows mutable, fixed size, and immutable maps the ability to remove elements from their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original minus all of the keys and values to be removed. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken: 
       map = map.withoutAllKeys(FastList.newListWith("key1", "key2"));
      In the case of FixedSizeMap, a new instance will be returned by withoutAllKeys, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling remove on themselves.
      Specified by:
      withoutAllKeys in interface MutableMapIterable<K,V>
      See Also: