import java.util.TreeMap;
//计算字符串中子串出现的次数
public class Test {
public static void main(String[] args) {
TreeMap<Character,Integer > tm = new TreeMap<>();
String s = "nalskjoiw eaoijajkwlcx aksoiaa lzndoiawlksnnz";
char[] chs = s.toCharArray();
for (char c : chs) {
if(!tm.containsKey(c)){
tm.put(c, 1);
}else{
tm.put(c, tm.get(c)+1);
}
}
for (Character c : tm.keySet()) {
System.out.println(c + "---" +tm.get(c));
}
}
}