通过键盘输入一串小写字母(a~z)组成的字符串

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

/**

• @auther 付强
• @date 2020/3/15 - 10:26
• /
  public class Main {
  public static void main(String[] args) {

    Scanner scanner=new Scanner(System.in);
    String s = scanner.nextLine();
    HashMap<Character,Integer> map=new HashMap<Character, Integer>();
    for(int i=0;i<s.length();i++){
        char c = s.charAt(i);
        int num=1;
        if(c!=' '){
            if(map.get(c)==null){
                map.put(c,1);
            }else if(map.get(c)!=0){
                num=map.get(c);
                map.put(c,num+1);
            }
        }
    }
    StringBuilder sb=new StringBuilder();
    for (Map.Entry<Character, Integer> entry : map.entrySet()) {
        sb.append(entry.getKey());
        sb.append(entry.getValue());
    }
    System.out.println(sb.toString());

  }
  }
  利用一个key,value来进行存值最后tostring获得结果