E
- the type of elements returned by this enumerationNamingEnumeration<T>
StringTokenizer
public interface Enumeration<E>
nextElement
method return successive elements of the series. For example, to print all elements of a Vector<E>
v:
for (Enumeration<E> e = v.elements(); e.hasMoreElements();) System.out.println(e.nextElement());
Methods are provided to enumerate through the elements of a vector, the keys of a hashtable, and the values in a hashtable. Enumerations are also used to specify the input streams to a SequenceInputStream
.
Iterator
interface. In addition, Iterator
adds an optional remove operation, and has shorter method names. New implementations should consider using Iterator
in preference to Enumeration
. It is possible to adapt an Enumeration
to an Iterator
by using the asIterator()
method.Modifier and Type | Method | Description |
---|---|---|
default Iterator |
asIterator() |
Returns an Iterator that traverses the remaining elements covered by this enumeration. |
boolean |
hasMoreElements() |
Tests if this enumeration contains more elements. |
E |
nextElement() |
Returns the next element of this enumeration if this enumeration object has at least one more element to provide. |
boolean hasMoreElements()
true
if and only if this enumeration object contains at least one more element to provide; false
otherwise.E nextElement()
NoSuchElementException
- if no more elements exist.default Iterator<E> asIterator()
Iterator
that traverses the remaining elements covered by this enumeration. Traversal is undefined if any methods are called on this enumeration after the call to asIterator
.Enumeration
instances to code that consumes Iterator
instances. For example, the JarFile.entries()
method returns an Enumeration<JarEntry>
. This can be turned into an Iterator
, and then the forEachRemaining()
method can be used:
JarFile jarFile = ... ;
jarFile.entries().asIterator().forEachRemaining(entry -> { ... });
(Note that there is also a JarFile.stream()
method that returns a Stream
of entries, which may be more convenient in some cases.)Iterator
whose hasNext
method calls this Enumeration's hasMoreElements
method, whose next
method calls this Enumeration's nextElement
method, and whose remove
method throws UnsupportedOperationException
.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/Enumeration.html