java.lang.Object
- java.util.AbstractCollection<E>
- - com.google.common.collect.ImmutableCollection<E>
  - - com.google.common.collect.ImmutableSet<E>

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable<E>, java.util.Collection<E>, java.util.Set<E>

Direct Known Subclasses:

ImmutableSortedSet
```
@GwtCompatible(serializable=true,
               emulated=true)
public abstract class ImmutableSet<E>
extends ImmutableCollection<E>
implements java.util.Set<E>
```
A Set whose contents will never change, with many other important properties detailed at ImmutableCollection.

Since:

2.0

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class ImmutableSet.Builder<E>
A builder for creating ImmutableSet instances.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`static <E> ImmutableSet.Builder<E>`	`builder()`	Returns a new builder.
`static <E> ImmutableSet.Builder<E>`	`builderWithExpectedSize(int expectedSize)`	Returns a new builder, expecting the specified number of distinct elements to be added.
`static <E> ImmutableSet<E>`	`copyOf(E[] elements)`	Returns an immutable set containing each of `elements`, minus duplicates, in the order each appears first in the source array.
`static <E> ImmutableSet<E>`	`copyOf(java.lang.Iterable<? extends E> elements)`	Returns an immutable set containing each of `elements`, minus duplicates, in the order each appears first in the source iterable.
`static <E> ImmutableSet<E>`	`copyOf(java.util.Collection<? extends E> elements)`	Returns an immutable set containing each of `elements`, minus duplicates, in the order each appears first in the source collection.
`static <E> ImmutableSet<E>`	`copyOf(java.util.Iterator<? extends E> elements)`	Returns an immutable set containing each of `elements`, minus duplicates, in the order each appears first in the source iterator.
`boolean`	`equals(java.lang.Object object)`
`int`	`hashCode()`
`abstract UnmodifiableIterator<E>`	`iterator()`	Returns an unmodifiable iterator across the elements in this collection.
`static <E> ImmutableSet<E>`	`of()`	Returns the empty immutable set.
`static <E> ImmutableSet<E>`	`of(E element)`	Returns an immutable set containing `element`.
`static <E> ImmutableSet<E>`	`of(E e1, E e2)`	Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
`static <E> ImmutableSet<E>`	`of(E e1, E e2, E e3)`	Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
`static <E> ImmutableSet<E>`	`of(E e1, E e2, E e3, E e4)`	Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
`static <E> ImmutableSet<E>`	`of(E e1, E e2, E e3, E e4, E e5)`	Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
`static <E> ImmutableSet<E>`	`of(E e1, E e2, E e3, E e4, E e5, E e6, E... others)`	Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified.
`static <E> java.util.stream.Collector<E,?,ImmutableSet<E>>`	`toImmutableSet()`	Returns a `Collector` that accumulates the input elements into a new `ImmutableSet`.

Methods inherited from class com.google.common.collect.ImmutableCollection
add, addAll, asList, clear, contains, remove, removeAll, removeIf, retainAll, spliterator, toArray, toArray

Methods inherited from class java.util.AbstractCollection
containsAll, isEmpty, size, toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable
forEach

Methods inherited from interface java.util.Set
add, addAll, clear, contains, containsAll, isEmpty, remove, removeAll, retainAll, size, spliterator, toArray, toArray

- Method Detail
  - toImmutableSet
```
public static <E> java.util.stream.Collector<E,?,ImmutableSet<E>> toImmutableSet()
```
    Returns a Collector that accumulates the input elements into a new ImmutableSet. Elements appear in the resulting set in the encounter order of the stream; if the stream contains duplicates (according to Object.equals(Object)), only the first duplicate in encounter order will appear in the result.
    
    Since:
    
    21.0
  - of
```
public static <E> ImmutableSet<E> of()
```
    Returns the empty immutable set. Preferred over Collections.emptySet() for code consistency, and because the return type conveys the immutability guarantee.
    Performance note: the instance returned is a singleton.
  - of
```
public static <E> ImmutableSet<E> of(E element)
```
    Returns an immutable set containing element. Preferred over Collections.singleton(T) for code consistency, null rejection, and because the return type conveys the immutability guarantee.
  - of
```
public static <E> ImmutableSet<E> of(E e1,
                                     E e2)
```
    Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
  - of
```
public static <E> ImmutableSet<E> of(E e1,
                                     E e2,
                                     E e3)
```
    Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
  - of
```
public static <E> ImmutableSet<E> of(E e1,
                                     E e2,
                                     E e3,
                                     E e4)
```
    Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
  - of
```
public static <E> ImmutableSet<E> of(E e1,
                                     E e2,
                                     E e3,
                                     E e4,
                                     E e5)
```
    Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
  - of
```
@SafeVarargs
public static <E> ImmutableSet<E> of(E e1,
                                     E e2,
                                     E e3,
                                     E e4,
                                     E e5,
                                     E e6,
                                     E... others)
```
    Returns an immutable set containing the given elements, minus duplicates, in the order each was first specified. That is, if multiple elements are equal, all except the first are ignored.
    The array others must not be longer than Integer.MAX_VALUE - 6.
    
    Since:
    
    3.0 (source-compatible since 2.0)
  - copyOf
```
public static <E> ImmutableSet<E> copyOf(java.util.Collection<? extends E> elements)
```
    Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source collection.
    Performance note: This method will sometimes recognize that the actual copy operation is unnecessary; for example, copyOf(copyOf(anArrayList)) will copy the data only once. This reduces the expense of habitually making defensive copies at API boundaries. However, the precise conditions for skipping the copy operation are undefined.
    
    Throws:
    
    java.lang.NullPointerException - if any of elements is null
    
    Since:
    
    7.0 (source-compatible since 2.0)
  - copyOf
```
public static <E> ImmutableSet<E> copyOf(java.lang.Iterable<? extends E> elements)
```
    Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source iterable. This method iterates over elements only once.
    Performance note: This method will sometimes recognize that the actual copy operation is unnecessary; for example, copyOf(copyOf(anArrayList)) should copy the data only once. This reduces the expense of habitually making defensive copies at API boundaries. However, the precise conditions for skipping the copy operation are undefined.
    
    Throws:
    
    java.lang.NullPointerException - if any of elements is null
  - copyOf
```
public static <E> ImmutableSet<E> copyOf(java.util.Iterator<? extends E> elements)
```
    Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source iterator.
    
    Throws:
    
    java.lang.NullPointerException - if any of elements is null
  - copyOf
```
public static <E> ImmutableSet<E> copyOf(E[] elements)
```
    Returns an immutable set containing each of elements, minus duplicates, in the order each appears first in the source array.
    
    Throws:
    
    java.lang.NullPointerException - if any of elements is null
    
    Since:
    
    3.0
  - equals
```
public boolean equals(@CheckForNull
                      java.lang.Object object)
```
    Specified by:
    
    equals in interface java.util.Collection<E>
    
    Specified by:
    
    equals in interface java.util.Set<E>
    
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface java.util.Collection<E>
    
    Specified by:
    
    hashCode in interface java.util.Set<E>
    
    Overrides:
    
    hashCode in class java.lang.Object
  - iterator
```
public abstract UnmodifiableIterator<E> iterator()
```
    Description copied from class: ImmutableCollection
    
    Returns an unmodifiable iterator across the elements in this collection.
    
    Specified by:
    
    iterator in interface java.util.Collection<E>
    
    Specified by:
    
    iterator in interface java.lang.Iterable<E>
    
    Specified by:
    
    iterator in interface java.util.Set<E>
    
    Specified by:
    
    iterator in class ImmutableCollection<E>
  - builder
```
public static <E> ImmutableSet.Builder<E> builder()
```
    Returns a new builder. The generated builder is equivalent to the builder created by the ImmutableSet.Builder constructor.
  - builderWithExpectedSize
```
public static <E> ImmutableSet.Builder<E> builderWithExpectedSize(int expectedSize)
```
    Returns a new builder, expecting the specified number of distinct elements to be added.
    If expectedSize is exactly the number of distinct elements added to the builder before ImmutableSet.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 distinct elements added to the builder.
    
    Since:
    
    23.1

Class ImmutableSet<E>

Nested Class Summary

Method Summary

Methods inherited from class com.google.common.collect.ImmutableCollection

Methods inherited from class java.util.AbstractCollection

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Collection

Methods inherited from interface java.lang.Iterable

Methods inherited from interface java.util.Set

Method Detail

toImmutableSet

of

of

of

of

of

of

of

copyOf

copyOf

copyOf

copyOf

equals

hashCode

iterator

builder

builderWithExpectedSize