java::util::Collection Class Reference

The root interface in the collection hierarchy. More...

#include <java_util_Collection.h>

Inheritance diagram for java::util::Collection:

[legend]Collaboration diagram for java::util::Collection:

[legend]List of all members.

Public Types
enum	{   xmogDefaultFlags = xmog_base::GLOBAL, xmogMajorVersion = 3, xmogMinorVersion = 2, xmogPatchVersion = 9,   xmogBuildNumber = 2047 }
typedef ::xmog_java_array_template< ::java::util::Collection >	array1D
typedef ::xmog_java_array_template< ::xmog_java_array_template< ::java::util::Collection > >	array2D
Public Member Functions
virtual bool	add (const ::java::lang::Object &o,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Ensures that this collection contains the specified element (optional operation).
virtual bool	addAll (const ::java::util::Collection &c,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Adds all of the elements in the specified collection to this collection (optional operation).
virtual void	clear (::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Removes all of the elements from this collection (optional operation).
virtual bool	contains (const ::java::lang::Object &o,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns true if this collection contains the specified element.
virtual bool	containsAll (const ::java::util::Collection &c,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns true if this collection contains all of the elements in the specified collection.
virtual bool	equals (const ::java::lang::Object &o,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Compares the specified object with this collection for equality.
virtual jint	hashCode (::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns the hash code value for this collection.
virtual bool	isEmpty (::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns true if this collection contains no elements.
virtual ::java::util::Iterator	iterator (::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns an iterator over the elements in this collection.
virtual bool	remove (const ::java::lang::Object &o,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Removes a single instance of the specified element from this collection, if it is present (optional operation).
virtual bool	removeAll (const ::java::util::Collection &c,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Removes all this collection's elements that are also contained in the specified collection (optional operation).
virtual bool	retainAll (const ::java::util::Collection &c,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Retains only the elements in this collection that are contained in the specified collection (optional operation).
virtual jint	size (::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns the number of elements in this collection.
virtual ::xmog_java_array_template< ::java::lang::Object >	toArray (const ::xmog_java_array_template< ::java::lang::Object > &a,::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
virtual ::xmog_java_array_template< ::java::lang::Object >	toArray (::xmog_localenv *p_xenv=NULL, xmog_flags f_xflags=xmogDefaultFlags)
	Returns an array containing all of the elements in this collection.

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Detailed Description

The root interface in the collection hierarchy.

A collection represents a group of objects, known as its elements. Some collections allow duplicate elements and others do not. Some are ordered and others unordered. The SDK does not provide any direct implementations of this interface: it provides implementations of more specific subinterfaces like Set and List. This interface is typically used to pass collections around and manipulate them where maximum generality is desired.

Bags or multisets (unordered collections that may contain duplicate elements) should implement this interface directly.

All general-purpose Collection implementation classes (which typically implement Collection indirectly through one of its subinterfaces) should provide two "standard" constructors: a void (no arguments) constructor, which creates an empty collection, and a constructor with a single argument of type Collection, which creates a new collection with the same elements as its argument. In effect, the latter constructor allows the user to copy any collection, producing an equivalent collection of the desired implementation type. There is no way to enforce this convention (as interfaces cannot contain constructors) but all of the general-purpose Collection implementations in the Java platform libraries comply.

The "destructive" methods contained in this interface, that is, the methods that modify the collection on which they operate, are specified to throw UnsupportedOperationException if this collection does not support the operation. If this is the case, these methods may, but are not required to, throw an UnsupportedOperationException if the invocation would have no effect on the collection. For example, invoking the method on an unmodifiable collection may, but is not required to, throw the exception if the collection to be added is empty.

Some collection implementations have restrictions on the elements that they may contain. For example, some implementations prohibit null elements, and some have restrictions on the types of their elements. Attempting to add an ineligible element throws an unchecked exception, typically NullPointerException or ClassCastException. Attempting to query the presence of an ineligible element may throw an exception, or it may simply return false; some implementations will exhibit the former behavior and some will exhibit the latter. More generally, attempting an operation on an ineligible element whose completion would not result in the insertion of an ineligible element into the collection may throw an exception or it may succeed, at the option of the implementation. Such exceptions are marked as "optional" in the specification for this interface.

This interface is a member of the Java Collections Framework.

Author:

Josh Bloch

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Member Function Documentation

virtual bool java::util::Collection::add (  const ::java::lang::Object &  o, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

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. Parameters: o  element whose presence in this collection is to be ensured. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection changed as a result of the call Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual bool java::util::Collection::addAll (  const ::java::util::Collection &  c, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

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.) Parameters: c  elements to be inserted into this collection. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection changed as a result of the call Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::List, java::util::Set, and java::util::Vector.

virtual void java::util::Collection::clear (  ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

Removes all of the elements from this collection (optional operation). This collection will be empty after this method returns unless it throws an exception. Parameters: p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual bool java::util::Collection::contains (  const ::java::lang::Object &  o, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

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)). Parameters: o  element whose presence in this collection is to be tested. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection contains the specified element Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual bool java::util::Collection::containsAll (  const ::java::util::Collection &  c, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

Returns true if this collection contains all of the elements in the specified collection. Parameters: c  collection to be checked for containment in this collection. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection contains all of the elements in the specified collection Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::List, java::util::Set, and java::util::Vector.

virtual bool java::util::Collection::equals (  const ::java::lang::Object &  o, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

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 implementer 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.) Parameters: o  Object to be compared for equality with this collection. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if the specified object is equal to this collection Reimplemented from java::lang::Object. Reimplemented in java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual jint java::util::Collection::hashCode (  ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

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(). Parameters: p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: the hash code value for this collection Reimplemented from java::lang::Object. Reimplemented in java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual bool java::util::Collection::isEmpty (  ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

Returns true if this collection contains no elements. Parameters: p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection contains no elements Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual ::java::util::Iterator java::util::Collection::iterator (  ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )

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). Parameters: p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: an Iterator over the elements in this collection Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::HashSet, java::util::List, and java::util::Set.

virtual bool java::util::Collection::remove (  const ::java::lang::Object &  o, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

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). Parameters: o  element to be removed from this collection, if present. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection changed as a result of the call Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual bool java::util::Collection::removeAll (  const ::java::util::Collection &  c, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

Removes all 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. Parameters: c  elements to be removed from this collection. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection changed as a result of the call Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::List, java::util::Set, and java::util::Vector.

virtual bool java::util::Collection::retainAll (  const ::java::util::Collection &  c, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

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. Parameters: c  elements to be retained in this collection. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: true if this collection changed as a result of the call Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::List, java::util::Set, and java::util::Vector.

virtual jint java::util::Collection::size (  ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )  [virtual]

Returns the number of elements in this collection. If this collection contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE. Parameters: p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: the number of elements in this collection Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::HashSet, java::util::List, java::util::Set, and java::util::Vector.

virtual ::xmog_java_array_template< ::java::lang::Object > java::util::Collection::toArray (  const ::xmog_java_array_template< ::java::lang::Object > &  a, ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )

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 l is a List known to contain only strings. The following code can be used to dump the list into a newly allocated array of String: String[] x = (String[]) v.toArray(new String[0]); Note that toArray(new Object[0]) is identical in function to toArray(). 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. p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: an array containing the elements of this collection Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::List, java::util::Set, and java::util::Vector.

virtual ::xmog_java_array_template< ::java::lang::Object > java::util::Collection::toArray (  ::xmog_localenv *  p_xenv = NULL, xmog_flags  f_xflags = xmogDefaultFlags )

Returns an array containing all of the elements in this collection. If the 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. Parameters: p_xenv  the local call environment. The default value is NULL. f_xflags  the flags that allow control over the reference type and other internal matters. The default value is xmog_base::GLOBAL. Returns: an array containing all of the elements in this collection Reimplemented in java::util::AbstractCollection, java::util::AbstractList, java::util::AbstractSet, java::util::ArrayList, java::util::List, java::util::Set, and java::util::Vector.

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The documentation for this class was generated from the following file:

• java_util_Collection.h

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