char[]charArray
= str.toCharArray();
Map<Character,Integer> map = new TreeMap<Character,Integer>();
for(int i=0;i<charArray.length;i++){
Integer value = map.get(charArray[i]);if(value == null)
value = 0;
map.put(charArray[i], value + 1);
}
char[]charArray
= str.toCharArray();
Map<Character,Integer> map = new TreeMap<Character,Integer>();
for(int i=0;i<charArray.length;i++){
Integer value = map.get(charArray[i]);