Class CheckedCollection
- All Implemented Interfaces:
Iterable
,Collection
,Set
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected Collection
The collection.protected Exception
The last modification.protected CheckedMap
The paretn map (if any). -
Constructor Summary
ConstructorsConstructorDescriptionCheckedCollection
(Collection coll) Create a new collection.CheckedCollection
(Collection coll, CheckedMap parent) Create a new collection. -
Method Summary
Modifier and TypeMethodDescriptionboolean
Ensures that this collection contains the specified element (optional operation).boolean
addAll
(Collection c) Adds all of the elements in the specified collection to this collection (optional operation).void
clear()
Removes all of the elements from this collection (optional operation).boolean
Returns true if this collection contains the specified element.boolean
Returns true if this collection contains all of the elements in the specified collection.boolean
Compares the specified object with this collection for equality.int
hashCode()
Returns the hash code value for this collection.boolean
isEmpty()
Returns true if this collection contains no elements.iterator()
Returns an iterator over the elements in this collection.boolean
Removes a single instance of the specified element from this collection, if it is present (optional operation).boolean
Removes all of this collection's elements that are also contained in the specified collection (optional operation).boolean
Retains only the elements in this collection that are contained in the specified collection (optional operation).int
size()
Returns the number of elements in this collection.Object[]
toArray()
Returns an array containing all of the elements in this collection.Object[]
Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface java.util.Collection
parallelStream, removeIf, stream, toArray
Methods inherited from interface java.util.Set
spliterator
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Field Details
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coll
The collection. -
lastmod
The last modification. -
parent
The paretn map (if any).
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Constructor Details
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CheckedCollection
Create a new collection. -
CheckedCollection
Create a new collection.
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Method Details
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size
public int size()Returns the number of elements in this collection. If this collection contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.- Specified by:
size
in interfaceCollection
- Specified by:
size
in interfaceSet
- Returns:
- the number of elements in this collection
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isEmpty
public boolean isEmpty()Returns true if this collection contains no elements.- Specified by:
isEmpty
in interfaceCollection
- Specified by:
isEmpty
in interfaceSet
- Returns:
- true if this collection contains no elements
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contains
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 (o==null ? e==null : o.equals(e)).- Specified by:
contains
in interfaceCollection
- Specified by:
contains
in interfaceSet
- Parameters:
o
- element whose presence in this collection is to be tested- Returns:
- true if this collection contains the specified element
- Throws:
ClassCastException
- if the type of the specified element is incompatible with this collection (optional)NullPointerException
- if the specified element is null and this collection does not permit null elements (optional)
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iterator
Returns an iterator over the elements in this collection. There are no guarantees concerning the order in which the elements are returned (unless this collection is an instance of some class that provides a guarantee). -
toArray
Returns an array containing all of the elements in this collection. If this collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order.The returned array will be "safe" in that no references to it are maintained by this collection. (In other words, this method must allocate a new array even if this collection is backed by an array). The caller is thus free to modify the returned array.
This method acts as bridge between array-based and collection-based APIs.
- Specified by:
toArray
in interfaceCollection
- Specified by:
toArray
in interfaceSet
- Returns:
- an array containing all of the elements in this collection
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toArray
Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array. If the collection fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this collection.If this collection fits in the specified array with room to spare (i.e., the array has more elements than this collection), the element in the array immediately following the end of the collection is set to null. (This is useful in determining the length of this collection only if the caller knows that this collection does not contain any null elements.)
If this collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order.
Like the
toArray()
method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs.Suppose x is a collection known to contain only strings. The following code can be used to dump the collection into a newly allocated array of String:
String[] y = x.toArray(new String[0]);
Note that toArray(new Object[0]) is identical in function to toArray().- Specified by:
toArray
in interfaceCollection
- Specified by:
toArray
in interfaceSet
- Parameters:
a
- the array into which the elements of this collection are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.- Returns:
- an array containing all of the elements in this collection
- Throws:
ArrayStoreException
- if the runtime type of the specified array is not a supertype of the runtime type of every element in this collectionNullPointerException
- if the specified array is null
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add
Ensures that this collection contains the specified element (optional operation). Returns true if this collection changed as a result of the call. (Returns false if this collection does not permit duplicates and already contains the specified element.)Collections that support this operation may place limitations on what elements may be added to this collection. In particular, some collections will refuse to add null elements, and others will impose restrictions on the type of elements that may be added. Collection classes should clearly specify in their documentation any restrictions on what elements may be added.
If a collection refuses to add a particular element for any reason other than that it already contains the element, it must throw an exception (rather than returning false). This preserves the invariant that a collection always contains the specified element after this call returns.
- Specified by:
add
in interfaceCollection
- Specified by:
add
in interfaceSet
- Parameters:
e
- element whose presence in this collection is to be ensured- Returns:
- true if this collection changed as a result of the call
- Throws:
UnsupportedOperationException
- if the add operation is not supported by this collectionClassCastException
- if the class of the specified element prevents it from being added to this collectionNullPointerException
- if the specified element is null and this collection does not permit null elementsIllegalArgumentException
- if some property of the element prevents it from being added to this collectionIllegalStateException
- if the element cannot be added at this time due to insertion restrictions
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remove
Removes a single instance of the specified element from this collection, if it is present (optional operation). More formally, removes an element e such that (o==null ? e==null : o.equals(e)), if this collection contains one or more such elements. Returns true if this collection contained the specified element (or equivalently, if this collection changed as a result of the call).- Specified by:
remove
in interfaceCollection
- Specified by:
remove
in interfaceSet
- Parameters:
o
- element to be removed from this collection, if present- Returns:
- true if an element was removed as a result of this call
- Throws:
ClassCastException
- if the type of the specified element is incompatible with this collection (optional)NullPointerException
- if the specified element is null and this collection does not permit null elements (optional)UnsupportedOperationException
- if the remove operation is not supported by this collection
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containsAll
Returns true if this collection contains all of the elements in the specified collection.- Specified by:
containsAll
in interfaceCollection
- Specified by:
containsAll
in interfaceSet
- Parameters:
c
- collection to be checked for containment in this collection- Returns:
- true if this collection contains all of the elements in the specified collection
- Throws:
ClassCastException
- if the types of one or more elements in the specified collection are incompatible with this collection (optional)NullPointerException
- if the specified collection contains one or more null elements and this collection does not permit null elements (optional), or if the specified collection is null- See Also:
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addAll
Adds all of the elements in the specified collection to this collection (optional operation). The behavior of this operation is undefined if the specified collection is modified while the operation is in progress. (This implies that the behavior of this call is undefined if the specified collection is this collection, and this collection is nonempty.)- Specified by:
addAll
in interfaceCollection
- Specified by:
addAll
in interfaceSet
- Parameters:
c
- collection containing elements to be added to this collection- Returns:
- true if this collection changed as a result of the call
- Throws:
UnsupportedOperationException
- if the addAll operation is not supported by this collectionClassCastException
- if the class of an element of the specified collection prevents it from being added to this collectionNullPointerException
- if the specified collection contains a null element and this collection does not permit null elements, or if the specified collection is nullIllegalArgumentException
- if some property of an element of the specified collection prevents it from being added to this collectionIllegalStateException
- if not all the elements can be added at this time due to insertion restrictions- See Also:
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removeAll
Removes all of this collection's elements that are also contained in the specified collection (optional operation). After this call returns, this collection will contain no elements in common with the specified collection.- Specified by:
removeAll
in interfaceCollection
- Specified by:
removeAll
in interfaceSet
- Parameters:
c
- collection containing elements to be removed from this collection- Returns:
- true if this collection changed as a result of the call
- Throws:
UnsupportedOperationException
- if the removeAll method is not supported by this collectionClassCastException
- if the types of one or more elements in this collection are incompatible with the specified collection (optional)NullPointerException
- if this collection contains one or more null elements and the specified collection does not support null elements (optional), or if the specified collection is null- See Also:
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retainAll
Retains only the elements in this collection that are contained in the specified collection (optional operation). In other words, removes from this collection all of its elements that are not contained in the specified collection.- Specified by:
retainAll
in interfaceCollection
- Specified by:
retainAll
in interfaceSet
- Parameters:
c
- collection containing elements to be retained in this collection- Returns:
- true if this collection changed as a result of the call
- Throws:
UnsupportedOperationException
- if the retainAll operation is not supported by this collectionClassCastException
- if the types of one or more elements in this collection are incompatible with the specified collection (optional)NullPointerException
- if this collection contains one or more null elements and the specified collection does not permit null elements (optional), or if the specified collection is null- See Also:
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clear
public void clear()Removes all of the elements from this collection (optional operation). The collection will be empty after this method returns.- Specified by:
clear
in interfaceCollection
- Specified by:
clear
in interfaceSet
- Throws:
UnsupportedOperationException
- if the clear operation is not supported by this collection
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equals
Compares the specified object with this collection for equality.While the Collection interface adds no stipulations to the general contract for the Object.equals, programmers who implement the Collection interface "directly" (in other words, create a class that is a Collection but is not a Set or a List) must exercise care if they choose to override the Object.equals. It is not necessary to do so, and the simplest course of action is to rely on Object's implementation, but the implementor may wish to implement a "value comparison" in place of the default "reference comparison." (The List and Set interfaces mandate such value comparisons.)
The general contract for the Object.equals method states that equals must be symmetric (in other words, a.equals(b) if and only if b.equals(a)). The contracts for List.equals and Set.equals state that lists are only equal to other lists, and sets to other sets. Thus, a custom equals method for a collection class that implements neither the List nor Set interface must return false when this collection is compared to any list or set. (By the same logic, it is not possible to write a class that correctly implements both the Set and List interfaces.)
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hashCode
public int hashCode()Returns the hash code value for this collection. While the Collection interface adds no stipulations to the general contract for the Object.hashCode method, programmers should take note that any class that overrides the Object.equals method must also override the Object.hashCode method in order to satisfy the general contract for the Object.hashCodemethod. In particular, c1.equals(c2) implies that c1.hashCode()==c2.hashCode().
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