Normalize string whitespaces with J2ME

A simple method to normalize String multiple whitespaces (replacing them with a single whitespace). For example, to normalize the String:
"     Normalize    all  whitespaces  "
to:
" Normalize all whitespaces ".

String normalizeWhitespaces(String s)
{
	StringBuffer res = new StringBuffer();
 
	int prevIndex = 0;
 
	int currIndex = -1;
 
	int stringLength = s.length();
 
	String searchString = "  ";
 
	while((currIndex = s.indexOf(searchString, currIndex + 1)) >= 0)
	{
		res.append(s.substring(prevIndex, currIndex + 1));
 
		while(currIndex < stringLength && s.charAt(currIndex) == ' ')
		{
			currIndex++;
		}
 
		prevIndex = currIndex;
	}
	res.append(s.substring(prevIndex));
 
	return res.toString();
}