第一个只出现一次的字符

 1 　　public int FirstNotRepeatingChar(String str){
 2         if(str==null)
 3             return -1;
 4         LinkedHashMap<Character, Integer> map = new LinkedHashMap<Character, Integer>();
 5         for(int i=0;i<str.length();i++){
 6             char c = str.charAt(i);
 7             if(map.containsKey(c)){
 8                 map.put(c, map.get(c)+1);
 9             }
10             else
11                 map.put(c, 1);
12         }
13         char temp = ‘ ‘;
14         for(Map.Entry<Character, Integer> m: map.entrySet()){
15             if(m.getValue()==1){
16                 temp = m.getKey();
17                 break;
18             }
19         }
20         return str.indexOf(temp);
21     }