How to count each character of a string in java

Copy the code code as follows:

/*
String name = "adsbsadgsadgtewterfsdf";
eg a-->6,b-->1 d-->3 ...
Ideas for storing the string in the Map collection framework with a (letter) => 2 (number): 1. Convert the string into a character array.
2. Define a Map collection, and then traverse the character array. If there is no such element in the Map collection, store the element in the Map collection, and define a counter to store the number of times in the Map to achieve the goal.

*/
import java.util.*;
classCharMapDemo
{
public static void main(String[] args)
{
String str = "abcedsadgsadfasdfaa";
TreeMap<Character,Integer> tm = Pross(str);
System.out.println(tm);
}
public static TreeMap<Character,Integer> Pross(String str)
{
char[] charArray = str.toCharArray();

TreeMap<Character,Integer> tm = new TreeMap<Character,Integer>();

for (int x = 0; x < charArray.length;x++)
{
if(!tm.containsKey(charArray[x]))
{
tm.put(charArray[x],1);
}
else
{
int count = tm.get(charArray[x])+1;
tm.put(charArray[x],count);
}
}
return tm;
}
}