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Class collections.FilteringEnumeration 

java.lang.Object
   |
   +----collections.FilteringEnumeration
public class FilteringEnumeration
extends Object
implements Enumeration
FilteringEnumerations allow you to filter out elements from other enumerations before they are seen by their `consumers' (i.e., the callers of `nextElement').

FilteringEnumerations work as wrappers around other Enumerations. To build one, you need an existing Enumeration (perhaps one from coll.elements(), for some Collection coll), and a Predicate object (i.e., implementing interface Predicate). For example, if you want to screen out everything but Panel objects from a collection coll that might hold things other than Panels, write something of the form: 

 Enumeration e = coll.elements();
 Enumeration panels = FilteringEnumeration(e, IsPanel);
 while (panels.hasMoreElements()) 
  doSomethingWith((Panel)(panels.nextElement()));
To use this, you will also need to write a little class of the form: 
 class IsPanel implements Predicate {
  boolean predicate(Object v) { return (v instanceof Panel); }
 }

See Also:
predicate

Constructor Index

o FilteringEnumeration(Enumeration, Predicate)
Make a Filter using src for the elements, and p as the screener, selecting only those elements of src for which p is true
o FilteringEnumeration(Enumeration, Predicate, boolean)
Make a Filter using src for the elements, and p as the screener, selecting only those elements of src for which p.predicate(v) == sense.

Method Index

o hasMoreElements()
Implements java.util.Enumeration.hasMoreElements
o nextElement()
Implements java.util.Enumeration.nextElement.

Constructors

o FilteringEnumeration 
 public FilteringEnumeration(Enumeration src,
                             Predicate p)
Make a Filter using src for the elements, and p as the screener, selecting only those elements of src for which p is true

o FilteringEnumeration 
 public FilteringEnumeration(Enumeration src,
                             Predicate p,
                             boolean sense)
Make a Filter using src for the elements, and p as the screener, selecting only those elements of src for which p.predicate(v) == sense. A value of true for sense selects only values for which p.predicate is true. A value of false selects only those for which it is false.

Methods

o hasMoreElements 
 public synchronized boolean hasMoreElements()
Implements java.util.Enumeration.hasMoreElements

o nextElement 
 public synchronized Object nextElement()
Implements java.util.Enumeration.nextElement. 

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