Java统计文件中每个字符出现的个数

package com.zhu.io;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

public class FileCharacter{
Map<Character,Integer>map=new TreeMap<Character,Integer>();
public FileCharacter(String fileName) throws IOException{
BufferedReader br=new BufferedReader(new FileReader(new File(fileName)));
int x;
while((x=br.read())>0){
Character key=new Character((char)x);
if(map.containsKey(key)){
int count=map.get(key);
map.remove(key);
map.put(key, ++count);
}else{
map.put(key, 1);
}
}
}
public int getCount(char c){           //获取字符在文件中出现的个数
return map.get(c);
}
public Set<Character> getAllChar(){     //获取文件中字符的Set集合
return map.keySet();
}
public Map<Character,Integer> getMap(){   //获取字符与其出现个数组成的Map集合
return map;
}
public void printInfo(){                 //打印信息
Set<Map.Entry<Character, Integer>>set=map.entrySet();
for(Map.Entry<Character, Integer> entry:set){
System.out.println("[ "+entry.getKey()+" ]"+"\t"+"count:"+entry.getValue());
}
}
public static void main(String[] args) throws IOException {
FileCharacter fc=new FileCharacter("e:\\test.txt");
fc.printInfo();
}
}