## com.google.common.collect
Class Constraints

    java.lang.Object
      com.google.common.collect.Constraints

    @Beta
    @GwtCompatible
    public final class Constraints

extends Object

Factories and utilities pertaining to the `Constraint` interface.

Since:
  3.0
Author:
  Mike Bostock, Jared Levy
See Also:
  `MapConstraints`

Method Summary

`static

`<E> Collection<E>`

`

`constrainedCollection(Collection<E> collection, Constraint<? super E> constraint)`
Returns a constrained view of the specified collection, using the specified constraint.

`static

`<E> List<E>`

`

`constrainedList(List<E> list, Constraint<? super E> constraint)`
Returns a constrained view of the specified list, using the specified constraint.

`static

`<E> Multiset<E>`

`

`constrainedMultiset(Multiset<E> multiset, Constraint<? super E> constraint)`
Returns a constrained view of the specified multiset, using the specified constraint.

`static

`<E> Set<E>`

`

`constrainedSet(Set<E> set, Constraint<? super E> constraint)`
Returns a constrained view of the specified set, using the specified constraint.

`static

`<E> SortedSet<E>`

`

`constrainedSortedSet(SortedSet<E> sortedSet, Constraint<? super E> constraint)`
Returns a constrained view of the specified sorted set, using the specified constraint.

`static

`<E> Constraint<E>`

`

`notNull()`
Returns a constraint that verifies that the element is not null.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Method Detail

### notNull

    public static <E> Constraint<E> notNull()

  Returns a constraint that verifies that the element is not null. If the element is null, a `NullPointerException` is thrown.

### constrainedCollection

    public static <E> Collection<E> constrainedCollection(Collection<E> collection,
                                                          Constraint<? super E> constraint)

  Returns a constrained view of the specified collection, using the specified constraint. Any operations that add new elements to the collection will call the provided constraint. However, this method does not verify that existing elements satisfy the constraint.

  The returned collection is not serializable.

  Parameters:
    `collection` - the collection to constrain
    `constraint` - the constraint that validates added elements
  Returns:
    a constrained view of the collection

### constrainedSet

    public static <E> Set<E> constrainedSet(Set<E> set,
                                            Constraint<? super E> constraint)

  Returns a constrained view of the specified set, using the specified constraint. Any operations that add new elements to the set will call the provided constraint. However, this method does not verify that existing elements satisfy the constraint.

  The returned set is not serializable.

  Parameters:
    `set` - the set to constrain
    `constraint` - the constraint that validates added elements
  Returns:
    a constrained view of the set

### constrainedSortedSet

    public static <E> SortedSet<E> constrainedSortedSet(SortedSet<E> sortedSet,
                                                        Constraint<? super E> constraint)

  Returns a constrained view of the specified sorted set, using the specified constraint. Any operations that add new elements to the sorted set will call the provided constraint. However, this method does not verify that existing elements satisfy the constraint.

  The returned set is not serializable.

  Parameters:
    `sortedSet` - the sorted set to constrain
    `constraint` - the constraint that validates added elements
  Returns:
    a constrained view of the sorted set

### constrainedList

    public static <E> List<E> constrainedList(List<E> list,
                                              Constraint<? super E> constraint)

  Returns a constrained view of the specified list, using the specified constraint. Any operations that add new elements to the list will call the provided constraint. However, this method does not verify that existing elements satisfy the constraint.

  If `list` implements `RandomAccess`, so will the returned list. The returned list is not serializable.

  Parameters:
    `list` - the list to constrain
    `constraint` - the constraint that validates added elements
  Returns:
    a constrained view of the list

### constrainedMultiset

    public static <E> Multiset<E> constrainedMultiset(Multiset<E> multiset,
                                                      Constraint<? super E> constraint)

  Returns a constrained view of the specified multiset, using the specified constraint. Any operations that add new elements to the multiset will call the provided constraint. However, this method does not verify that existing elements satisfy the constraint.

  The returned multiset is not serializable.

  Parameters:
    `multiset` - the multiset to constrain
    `constraint` - the constraint that validates added elements
  Returns:
    a constrained view of the multiset

Copyright © 2010-2012. All Rights Reserved.