src/org/argeo/util/DictionaryKeys.java

   1 package org.argeo.util;
   2
   3 import java.util.Dictionary;
   4 import java.util.Enumeration;
   5 import java.util.Iterator;
   6
   7 /**
   8  * Access the keys of a {@link String}-keyed {@link Dictionary} (common throughout
   9  * the OSGi APIs) as an {@link Iterable} so that they are easily usable in
  10  * for-each loops.
  11  */
  12 class DictionaryKeys implements Iterable<String> {
  13         private final Dictionary<String, ?> dictionary;
  14
  15         public DictionaryKeys(Dictionary<String, ?> dictionary) {
  16                 this.dictionary = dictionary;
  17         }
  18
  19         @Override
  20         public Iterator<String> iterator() {
  21                 return new KeyIterator(dictionary.keys());
  22         }
  23
  24         private static class KeyIterator implements Iterator<String> {
  25                 private final Enumeration<String> keys;
  26
  27                 KeyIterator(Enumeration<String> keys) {
  28                         this.keys = keys;
  29                 }
  30
  31                 @Override
  32                 public boolean hasNext() {
  33                         return keys.hasMoreElements();
  34                 }
  35
  36                 @Override
  37                 public String next() {
  38                         return keys.nextElement();
  39                 }
  40
  41         }
  42 }