Characters that appear only once for the first time (Java)

Characters that appear only once for the first time (Java)

Title: Find the first character that appears only once in a string (0 <= string length <= 10000, all composed of letters), and return its position, if not, return -1 (case-sensitive ).
Code:

import java.util.HashMap;
import java.util.Map;

/**
 * @desc 第一次只出现一次的字符
 * @autho  zhaoliang
 * @date 20200415
 */
public class Main50_ {
    //在一个字符串(0<=字符串长度<=10000，全部由字母组成)中找到第一个只出现一次的字符,
    // 并返回它的位置, 如果没有则返回 -1（需要区分大小写）.

    public int FirstNotRepeatingChar(String str) {

        Map<Character,Integer> map =new HashMap<>();

        for (int i = 0;i<str.length();i++){
            map.put(str.charAt(i),map.getOrDefault(str.charAt(i),0)+1);
        }
        for(int i = 0;i<str.length();i++){
            if (map.get(str.charAt(i))==1){
                return i;
            }
        }
        return -1;
    }
}