"aadfsdfdsfdsafafsafsawerewolfasd" ,不仅要输出出现过的字符还要输出每个字符出现了多少次

import java.awt.List;
import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.Set;

public class Exercise3 {
public static void main(String[] args){
Set set = new LinkedHashSet();
String string = "aadfsdfdsfdsafafsafsawerewolfasd";
char[] ch = string.toCharArray();
for(int i = 0; i < ch.length; i++){
set.add(ch[i]);
}
System.out.println(set);

ArrayList list = new ArrayList(set);
ArrayList list2 = new ArrayList();
for(int i = 0; i < ch.length; i++){
list2.add(ch[i]);
}
for(int i = 0; i < list.size(); i++){
int n = 0;
for(int j =0; j < list2.size(); j++){
if(list.get(i).equals(list2.get(j))){

n++;
}

}
System.out.print(list.get(i) + " : " + n + " . ");
}
}
}

//OutPut:

[a, d, f, s, w, e, r, o, l]

a : 7 . d : 5 . f : 7 . s : 6 . w : 2 . e : 2 . r : 1 . o : 1 . l : 1 .