【java】统计一篇英文文章每个字母出现的次数

try {FileReader file = new FileReader("D:/temp/data.xml");BufferedReader fr = new BufferedReader(file);try {String str="";str=fr.readLine();char[] array = str.toCharArray();TreeMap<Character, Integer> map= new TreeMap<Character, Integer>();for (int i = 0; i < array.length; i++) {array[i] = Character.toLowerCase(array[i]);if (array.length>1) {if (map.get(array[i])==null) {map.put(array[i], 1);}else {int value = map.get(array[i]).intValue();value++;map.put(array[i], value);}}}for(Map.Entry<Character, Integer> entry: map.entrySet()) { System.out.print(entry.getKey() + "--" + entry.getValue() + "\n");}fr.close();} catch (IOException e) {e.printStackTrace();}} catch (FileNotFoundException e) {e.printStackTrace();}