如何用java语言实现遍历字符串中每个字符出现的次数

遍历字符串中adaccvbvnmtmabdklelracuk每个字符出现的次数

package com.zuoye;

import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

public class ArrayDemo {

/**
*  遍历字符串中adaccvbvnmtmabdklelracuk每个字符出现的次数
*
*/
public static void main(String[] args) {
String str="adaccvbvnmtmabdklelracuk";
char[] ch=str.toCharArray();
TreeMap<Character, Integer> map=new TreeMap<Character, Integer>();
for(char c:ch){
Integer sum=map.get(c);
if(sum==null){
map.put(c, 1);
}else{
map.put(c,++sum);
}
}
StringBuilder sb=new StringBuilder();
Set<Character> set=map.keySet();
for(Character c:set){
sb.append(c).append(":").append(map.get(c)).append(",");
}
System.out.println("结果是："+sb.toString());
}

}