| java.lang.Object
 java.util.AbstractCollection
| AbstractCollection | | abstract public class AbstractCollection implements Collection<E>(Code) | | AbstractCollection is an abstract implementation of the Collection interface.
This implementation does not support adding. A subclass must implement the
abstract methods iterator() and size().
since:
1.2 |
| Constructor Summary | |
| protected | AbstractCollection()
Constructs a new instance of this AbstractCollection. |
| Method Summary | |
| public boolean | add(E object)
If the specified element is not contained within this collection, and
addition of this element succeeds, then true will be returned. | | public boolean | addAll(Collection<? extends E> collection)
Adds the objects in the specified Collection to this Collection. | | public void | clear()
Removes all the elements in this collection. | | public boolean | contains(Object object)
Searches this Collection for the specified object. | | public boolean | containsAll(Collection collection)
Searches this Collection for all objects in the specified Collection. | | public boolean | isEmpty()
Returns true if the collection has no element, otherwise false. | | abstract public Iterator<E> | iterator()
Answers an Iterator on the elements of this Collection. | | public boolean | remove(Object object)
Removes the first occurrence of the specified object from this
Collection. | | public boolean | removeAll(Collection collection)
Removes all occurrences in this Collection of each object in the
specified Collection. | | public boolean | retainAll(Collection collection)
Removes all objects from this Collection that are not contained in the
specified Collection. | | abstract public int | size()
Answers the number of elements in this Collection. | | public Object[] | toArray()
Answers a new array containing all elements contained in this Collection. | | public T[] | toArray(T[] contents)
Answers an array containing all elements contained in this Collection. | | public String | toString()
Answers the string representation of this Collection. |
| AbstractCollection | | protected AbstractCollection()(Code) | | Constructs a new instance of this AbstractCollection.
|
| add | | public boolean add(E object)(Code) | | If the specified element is not contained within this collection, and
addition of this element succeeds, then true will be returned. If the
specified element is already contained within this collection, or
duplication is not permitted, false will be returned. Different
implementations may add specific limitations on this method to filter
permitted elements. For example, in some implementation, null element may
be denied, and NullPointerException will be thrown out. These limitations
should be explicitly documented by specific collection implementation.
Add operation is not supported in this implementation, and
UnsupportedOperationException will always be thrown out.
Parameters:
object - the element to be added. true if the collection is changed successfully after invokingthis method. Otherwise, false.
throws:
UnsupportedOperationException - if add operation is not supported by this class.
throws:
NullPointerException - if null is used to invoke this method, and null is notpermitted by this collection.
throws:
ClassCastException - if the class type of the specified element is not compatiblewith the permitted class type.
throws:
IllegalArgumentException - if limitations of this collection prevent the specifiedelement from being added |
| addAll | | public boolean addAll(Collection<? extends E> collection)(Code) | | Adds the objects in the specified Collection to this Collection.
Parameters:
collection - the Collection of objects true if this Collection is modified, false otherwise
throws:
UnsupportedOperationException - when adding to this Collection is not supported
throws:
NullPointerException - if null is used to invoke this method |
| clear | | public void clear()(Code) | | Removes all the elements in this collection. This collection will be
cleared up after this operation. The operation iterates over the
collection, removes every element using Iterator.remove method.
UnsupportedOperationException will be thrown out if the iterator returned
by this collection does not implement the remove method and the
collection is not zero length.
throws:
UnsupportedOperationException - if this operation is not implemented. |
| contains | | public boolean contains(Object object)(Code) | | Searches this Collection for the specified object.
Parameters:
object - the object to search for true if object is an element of this Collection,false otherwise |
| containsAll | | public boolean containsAll(Collection collection)(Code) | | Searches this Collection for all objects in the specified Collection.
Parameters:
collection - the Collection of objects true if all objects in the specified Collection are elements ofthis Collection, false otherwise
throws:
NullPointerException - if null is used to invoke this method |
| isEmpty | | public boolean isEmpty()(Code) | | Returns true if the collection has no element, otherwise false.
true if the collection has no element. |
| iterator | | abstract public Iterator<E> iterator()(Code) | | Answers an Iterator on the elements of this Collection. A subclass must
implement the abstract methods iterator() and size().
an Iterator on the elements of this Collection
See Also: Iterator |
| remove | | public boolean remove(Object object)(Code) | | Removes the first occurrence of the specified object from this
Collection. This operation traverses over the collection, looking for the
specified object. Once the object is found, the object will be removed
from the collection using the iterator's remove method.
This collection will throw an UnsupportedOperationException if the
iterator returned does not implement remove method, and the specified
object is in this collection.
Parameters:
object - the object to remove true if this Collection is modified, false otherwise
throws:
UnsupportedOperationException - when removing from this Collection is not supported |
| removeAll | | public boolean removeAll(Collection collection)(Code) | | Removes all occurrences in this Collection of each object in the
specified Collection. This operation traverses over the collection
itself, to verify whether each element is contained in the specified
collection. The object will be removed from the collection itself using
the iterator's remove method if it is contained in the specified
collection.
This collection will throw an UnsupportedOperationException if the
iterator returned does not implement remove method, and the element in
the specified collection is contained in this collection.
Parameters:
collection - the Collection of objects to remove true if this Collection is modified, false otherwise
throws:
UnsupportedOperationException - when removing from this Collection is not supported
throws:
NullPointerException - if null is used to invoke this method |
| retainAll | | public boolean retainAll(Collection collection)(Code) | | Removes all objects from this Collection that are not contained in the
specified Collection. This operation traverses over the collection
itself, to verify whether any element is contained in the specified
collection. The object will be removed from the collection itself using
the iterator's remove method if it is not contained in the specified
collection.
This collection will throw an UnsupportedOperationException if the
iterator returned does not implement remove method, and the collection
itself does contain elements which do not exist in the specified
collection.
Parameters:
collection - the Collection of objects to retain true if this Collection is modified, false otherwise
throws:
UnsupportedOperationException - when removing from this Collection is not supported
throws:
NullPointerException - if null is used to invoke this method |
| size | | abstract public int size()(Code) | | Answers the number of elements in this Collection.
the number of elements in this Collection |
| toArray | | public Object[] toArray()(Code) | | Answers a new array containing all elements contained in this Collection.
All the elements in the array will not be referenced by the collection.
The elements in the returned array will be sorted to the same order as
those returned by the iterator of this collection itself if the
collection guarantees the order.
an array of the elements from this Collection |
| toArray | | public T[] toArray(T[] contents)(Code) | | Answers an array containing all elements contained in this Collection. If
the specified array is large enough to hold the elements, the specified
array is used, otherwise an array of the same type is created. If the
specified array is used and is larger than this Collection, the array
element following the collection elements is set to null.
Parameters:
contents - the array an array of the elements from this Collection
throws:
ArrayStoreException - when the type of an element in this Collection cannot bestored in the type of the specified array
throws:
NullPointerException - if null is used to invoke this method |
| toString | | public String toString()(Code) | | Answers the string representation of this Collection. The presentation
has a specific format. It is enclosed by square brackets ("[]"). Elements
are separated by ', ' (comma and space).
the string representation of this Collection |
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