Sort an HashMap based on the keys : HashMap « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. HashMap

import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;

public class Main {

  public static void main(String[] a) {
    Map<String, String> yourMap = new HashMap<String, String>();
    yourMap.put("1", "one");
    yourMap.put("2", "two");
    yourMap.put("3", "three");

    Map<String, String> sortedMap = new TreeMap<String, String>(yourMap);

    System.out.println(sortedMap);
  }
}
//{1=one, 2=two, 3=three}