2016年2月18日 星期四

public interface Enumeration

java.util

Interface Enumeration

  • All Known Subinterfaces:
    NamingEnumeration
    All Known Implementing Classes:
    StringTokenizer


    public interface Enumeration
    An object that implements the Enumeration interface generates a series of elements, one at a time. Successive calls to thenextElement method return successive elements of the series.For example, to print all elements of a Vector v:
       for (Enumeration 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.
    NOTE: The functionality of this interface is duplicated by the 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.
    Since:
    JDK1.0
    See Also:
    IteratorSequenceInputStreamnextElement()HashtableHashtable.elements()Hashtable.keys()Vector,Vector.elements()

      • Method Summary

        All MethodsInstance MethodsAbstract Methods
        Modifier and TypeMethod and Description
        booleanhasMoreElements()
        Tests if this enumeration contains more elements.
        EnextElement()
        Returns the next element of this enumeration if this enumeration object has at least one more element to provide.

      • Method Detail

        • hasMoreElements

          boolean hasMoreElements()
          Tests if this enumeration contains more elements.
          Returns:
          true if and only if this enumeration object contains at least one more element to provide; false otherwise.
        • nextElement

          E nextElement()
          Returns the next element of this enumeration if this enumeration object has at least one more element to provide.
          Returns:
          the next element of this enumeration.
          Throws:
          NoSuchElementException - if no more elements exist.

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