Class ImmutableList<E>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ImmutableList.Builder<E>
      A builder for creating immutable list instances, especially public static final lists ("constant lists").
    • Method Detail

      • toImmutableList

        public static <E> Collector<E,​?,​ImmutableList<E>> toImmutableList()
        Returns a Collector that accumulates the input elements into a new ImmutableList, in encounter order.
        Since:
        21.0
      • of

        public static <E> ImmutableList<E> of()
        Returns the empty immutable list. This list behaves and performs comparably to Collections.emptyList(), and is preferable mainly for consistency and maintainability of your code.

        Performance note: the instance returned is a singleton.

        Type Parameters:
        E - the List's element type
        Returns:
        an empty List
      • of

        public static <E> ImmutableList<E> of​(E element)
        Returns an immutable list containing a single element. This list behaves and performs comparably to Collections.singletonList(T), but will not accept a null element. It is preferable mainly for consistency and maintainability of your code.
        Type Parameters:
        E - the List's element type
        Parameters:
        element - the single element
        Returns:
        a List containing the specified element
        Throws:
        NullPointerException - if element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        e4 - the fourth element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        e4 - the fourth element
        e5 - the fifth element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5,
                                              E e6)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        e4 - the fourth element
        e5 - the fifth element
        e6 - the sixth element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5,
                                              E e6,
                                              E e7)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        e4 - the fourth element
        e5 - the fifth element
        e6 - the sixth element
        e7 - the seventh element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5,
                                              E e6,
                                              E e7,
                                              E e8)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        e4 - the fourth element
        e5 - the fifth element
        e6 - the sixth element
        e7 - the seventh element
        e8 - the eighth element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5,
                                              E e6,
                                              E e7,
                                              E e8,
                                              E e9)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        e4 - the fourth element
        e5 - the fifth element
        e6 - the sixth element
        e7 - the seventh element
        e8 - the eighth element
        e9 - the ninth element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5,
                                              E e6,
                                              E e7,
                                              E e8,
                                              E e9,
                                              E e10)
        Returns an immutable list containing the given elements, in order.
        Type Parameters:
        E - the List's element type
        Parameters:
        e1 - the first element
        e2 - the second element
        e3 - the third element
        e4 - the fourth element
        e5 - the fifth element
        e6 - the sixth element
        e7 - the seventh element
        e8 - the eighth element
        e9 - the ninth element
        e10 - the tenth element
        Returns:
        a List containing the specified elements
        Throws:
        NullPointerException - if any element is null
      • of

        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5,
                                              E e6,
                                              E e7,
                                              E e8,
                                              E e9,
                                              E e10,
                                              E e11)
        Returns an immutable list containing the given elements, in order.
        Throws:
        NullPointerException - if any element is null
      • of

        @SafeVarargs
        public static <E> ImmutableList<E> of​(E e1,
                                              E e2,
                                              E e3,
                                              E e4,
                                              E e5,
                                              E e6,
                                              E e7,
                                              E e8,
                                              E e9,
                                              E e10,
                                              E e11,
                                              E e12,
                                              E... others)
        Returns an immutable list containing the given elements, in order.

        The array others must not be longer than Integer.MAX_VALUE - 12.

        Throws:
        NullPointerException - if any element is null
        Since:
        3.0 (source-compatible since 2.0)
      • copyOf

        public static <E> ImmutableList<E> copyOf​(Collection<? extends E> elements)
        Returns an immutable list containing the given elements, in order.

        Despite the method name, this method attempts to avoid actually copying the data when it is safe to do so. The exact circumstances under which a copy will or will not be performed are undocumented and subject to change.

        Note that if list is a List<String>, then ImmutableList.copyOf(list) returns an ImmutableList<String> containing each of the strings in list, while ImmutableList.of(list)} returns an ImmutableList<List<String>> containing one element (the given list itself).

        This method is safe to use even when elements is a synchronized or concurrent collection that is currently being modified by another thread.

        Type Parameters:
        E - the List's element type
        Parameters:
        elements - a Collection from which elements are drawn, must be non-null
        Returns:
        a List containing the elements of the given Collection
        Throws:
        NullPointerException - if elements contains a null element
      • copyOf

        public static <E> ImmutableList<E> copyOf​(E[] elements)
        Returns an immutable list containing the given elements, in order.
        Throws:
        NullPointerException - if elements contains a null element
        Since:
        3.0
      • sortedCopyOf

        public static <E extends Comparable<? super E>> ImmutableList<E> sortedCopyOf​(Iterable<? extends E> elements)
        Returns an immutable list containing the given elements, sorted according to their natural order. The sorting algorithm used is stable, so elements that compare as equal will stay in the order in which they appear in the input.

        If your data has no duplicates, or you wish to deduplicate elements, use ImmutableSortedSet.copyOf(elements); if you want a List you can use its asList() view.

        Java 8 users: If you want to convert a Stream to a sorted ImmutableList, use stream.sorted().collect(toImmutableList()).

        Throws:
        NullPointerException - if any element in the input is null
        Since:
        21.0
      • sortedCopyOf

        public static <E> ImmutableList<E> sortedCopyOf​(Comparator<? super E> comparator,
                                                        Iterable<? extends E> elements)
        Returns an immutable list containing the given elements, in sorted order relative to the specified comparator. The sorting algorithm used is stable, so elements that compare as equal will stay in the order in which they appear in the input.

        If your data has no duplicates, or you wish to deduplicate elements, use ImmutableSortedSet.copyOf(comparator, elements); if you want a List you can use its asList() view.

        Java 8 users: If you want to convert a Stream to a sorted ImmutableList, use stream.sorted(comparator).collect(toImmutableList()).

        Throws:
        NullPointerException - if any element in the input is null
        Since:
        21.0
      • listIterator

        public UnmodifiableListIterator<ElistIterator​(int index)
        Description copied from interface: java.util.List
        Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list. The specified index indicates the first element that would be returned by an initial call to next. An initial call to previous would return the element with the specified index minus one.
        Specified by:
        listIterator in interface List<E>
        Parameters:
        index - index of the first element to be returned from the list iterator (by a call to next)
        Returns:
        a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list
      • forEach

        public void forEach​(Consumer<? super E> consumer)
        Description copied from interface: java.lang.Iterable
        Performs the given action for each element of the Iterable until all elements have been processed or the action throws an exception. Actions are performed in the order of iteration, if that order is specified. Exceptions thrown by the action are relayed to the caller.

        The behavior of this method is unspecified if the action performs side-effects that modify the underlying source of elements, unless an overriding class has specified a concurrent modification policy.

        Specified by:
        forEach in interface Iterable<E>
        Parameters:
        consumer - The action to be performed for each element
      • indexOf

        public int indexOf​(@CheckForNull
                           Object object)
        Description copied from interface: java.util.List
        Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the lowest index i such that Objects.equals(o, get(i)), or -1 if there is no such index.
        Specified by:
        indexOf in interface List<E>
        Parameters:
        object - element to search for
        Returns:
        the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element
      • lastIndexOf

        public int lastIndexOf​(@CheckForNull
                               Object object)
        Description copied from interface: java.util.List
        Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the highest index i such that Objects.equals(o, get(i)), or -1 if there is no such index.
        Specified by:
        lastIndexOf in interface List<E>
        Parameters:
        object - element to search for
        Returns:
        the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element
      • contains

        public boolean contains​(@CheckForNull
                                Object object)
        Description copied from class: java.util.AbstractCollection
        Returns true if this collection contains the specified element. More formally, returns true if and only if this collection contains at least one element e such that Objects.equals(o, e).
        Specified by:
        contains in interface Collection<E>
        Specified by:
        contains in interface List<E>
        Specified by:
        contains in class ImmutableCollection<E>
        Parameters:
        object - element whose presence in this collection is to be tested
        Returns:
        true if this collection contains the specified element
      • subList

        public ImmutableList<EsubList​(int fromIndex,
                                        int toIndex)
        Returns an immutable list of the elements between the specified fromIndex, inclusive, and toIndex, exclusive. (If fromIndex and toIndex are equal, the empty immutable list is returned.)
        Specified by:
        subList in interface List<E>
        Parameters:
        fromIndex - low endpoint (inclusive) of the subList
        toIndex - high endpoint (exclusive) of the subList
        Returns:
        a view of the specified range within this list
      • addAll

        @CanIgnoreReturnValue
        @Deprecated
        public final boolean addAll​(int index,
                                    Collection<? extends E> newElements)
        Deprecated.
        Unsupported operation.
        Guaranteed to throw an exception and leave the list unmodified.
        Specified by:
        addAll in interface List<E>
        Parameters:
        index - index at which to insert the first element from the specified collection
        newElements - collection containing elements to be added to this list
        Returns:
        true if this list changed as a result of the call
        Throws:
        UnsupportedOperationException - always
      • set

        @CanIgnoreReturnValue
        @Deprecated
        public final E set​(int index,
                           E element)
        Deprecated.
        Unsupported operation.
        Guaranteed to throw an exception and leave the list unmodified.
        Specified by:
        set in interface List<E>
        Parameters:
        index - index of the element to replace
        element - element to be stored at the specified position
        Returns:
        the element previously at the specified position
        Throws:
        UnsupportedOperationException - always
      • add

        @Deprecated
        public final void add​(int index,
                              E element)
        Deprecated.
        Unsupported operation.
        Guaranteed to throw an exception and leave the list unmodified.
        Specified by:
        add in interface List<E>
        Parameters:
        index - index at which the specified element is to be inserted
        element - element to be inserted
        Throws:
        UnsupportedOperationException - always
      • spliterator

        public Spliterator<Espliterator()
        Description copied from interface: java.util.Collection
        Creates a Spliterator over the elements in this collection. Implementations should document characteristic values reported by the spliterator. Such characteristic values are not required to be reported if the spliterator reports Spliterator.SIZED and this collection contains no elements.

        The default implementation should be overridden by subclasses that can return a more efficient spliterator. In order to preserve expected laziness behavior for the Collection.stream() and Collection.parallelStream() methods, spliterators should either have the characteristic of IMMUTABLE or CONCURRENT, or be late-binding. If none of these is practical, the overriding class should describe the spliterator's documented policy of binding and structural interference, and should override the Collection.stream() and Collection.parallelStream() methods to create streams using a Supplier of the spliterator, as in:

        
             Stream<E> s = StreamSupport.stream(() -> spliterator(), spliteratorCharacteristics)
         

        These requirements ensure that streams produced by the Collection.stream() and Collection.parallelStream() methods will reflect the contents of the collection as of initiation of the terminal stream operation.

        Specified by:
        spliterator in interface Collection<E>
        Specified by:
        spliterator in interface Iterable<E>
        Specified by:
        spliterator in interface List<E>
        Overrides:
        spliterator in class ImmutableCollection<E>
        Returns:
        a Spliterator over the elements in this collection
      • reverse

        public ImmutableList<Ereverse()
        Returns a view of this immutable list in reverse order. For example, ImmutableList.of(1, 2, 3).reverse() is equivalent to ImmutableList.of(3, 2, 1).
        Returns:
        a view of this immutable list in reverse order
        Since:
        7.0
      • equals

        public boolean equals​(@CheckForNull
                              Object obj)
        Description copied from class: java.lang.Object
        Indicates whether some other object is "equal to" this one.

        The equals method implements an equivalence relation on non-null object references:

        • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
        • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
        • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
        • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
        • For any non-null reference value x, x.equals(null) should return false.

        The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

        Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

        Specified by:
        equals in interface Collection<E>
        Specified by:
        equals in interface List<E>
        Overrides:
        equals in class Object
        Parameters:
        obj - the reference object with which to compare.
        Returns:
        true if this object is the same as the obj argument; false otherwise.
        See Also:
        Object.hashCode(), HashMap
      • hashCode

        public int hashCode()
        Description copied from class: java.lang.Object
        Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

        The general contract of hashCode is:

        • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
        • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
        • It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

        As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)

        Specified by:
        hashCode in interface Collection<E>
        Specified by:
        hashCode in interface List<E>
        Overrides:
        hashCode in class Object
        Returns:
        a hash code value for this object.
        See Also:
        Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)
      • builderWithExpectedSize

        @Beta
        public static <E> ImmutableList.Builder<E> builderWithExpectedSize​(int expectedSize)
        Returns a new builder, expecting the specified number of elements to be added.

        If expectedSize is exactly the number of elements added to the builder before ImmutableList.Builder.build() is called, the builder is likely to perform better than an unsized builder() would have.

        It is not specified if any performance benefits apply if expectedSize is close to, but not exactly, the number of elements added to the builder.

        Since:
        23.1