Sorting a Java Map

Hi,
a short post to show a simple tip useful when dealing with Java Maps.
The following Function sorts a Map through a custom Comparator and returns a new ordered LinkedHashMap:

	public static Map sortMapByKey(Map map, Comparator comparator) {
	    List list = new LinkedList(map.keySet());
	    Collections.sort(list, comparator);
	    Map result = new LinkedHashMap();
	    for (Object o : list) {
	        result.put(o, map.get(o));
	    }
	    return result;
	}

And this is an example of Comparator for MyClass objects sorted on the base of a String property “sortField” (note the toLowerCase method):

public class MyComparator implements Comparator {
	@Override
	public int compare(MyClass arg0, MyClass arg1) {
		if (arg0.getSortField() == null || arg1.getSortField() == null)
			return 0;
		String a = (arg0.getSortField()).toLowerCase();
		String b = (arg1.getSortField()).toLowerCase();
		return compareStringFirstChar(a, b);
	}
	
	private int compareStringFirstChar(String a, String b) {
		//a=b
		if(a == null || b == null || a.isEmpty() || b.isEmpty())
			return 0;
		//ab
		else if (a.charAt(0) > b.charAt(0))
			return 1;
		//zero a=b
		else
			return compareStringFirstChar(a.substring(1), b.substring(1));
	}
}