Sort Hashtable
A possibility to sort an Hashtable works as follows (Of course, not the Hashtable will be sorted, but the vector with the keys):
package com.sowas.javawiki.examples; import java.util.Hashtable; public class SortedHashtableExample { public static void main(String[] args) { Hashtable<String, Integer> ht = new Hashtable<String, Integer>(); ht.put("c", 3); ht.put("a", 1); ht.put("b", 2); Vector<String> v = new Vector<String>(ht.keySet()); Collections.sort(v); for (int i=0; i < v. size(); i++) { String key = v.elementAt(i); System.out.println(key + ": " + ht.get(key)); } } }
But if you want to sort Key-Value - Values, it is better to use a SortedMap instead of an Hashtable (e.g.: TreeMap):
package com.sowas.javawiki.examples; import java.util.SortedMap; import java.util.TreeMap; public class SortedMapExample { public static void main(String[] args) { SortedMap<String, Integer> map = new TreeMap<String, Integer>(); map.put("c", 3); map.put("a", 1); map.put("b", 2); for (String key : map.keySet()) { System.out.println(key + ": " + map.get(key)); } } }