Java统计字符串中每个字符出现的次数

统计字符串中每个字符出现的次数

1.输入一个字符串
2.统计个数
备注：利用TreeMap集合实现

public class chnums {
    public static void main(String[] args) {
        System.out.println("请输入一个字符");
        Scanner scanner = new Scanner(System.in);
        String line = scanner.nextLine();
        TreeMap<Character,Integer> tm=new TreeMap<Character, Integer>();
        for (int i = 0; i < line.length(); i++) {
            char key = line.charAt(i);
            Integer value = tm.get(key);
            if (value ==null){
                tm.put(key,1);
            }else {
                value++;
                tm.put(key,value);
            }
        }
        //可拼接成一个字符串
        //StringBuilder sb=new StringBuilder();

        Set<Character> keyset = tm.keySet();
        for (Character key:keyset){
            Integer value= tm.get(key);
            System.out.println(key+"("+value+")");
        }
    }
}
running：
请输入一个字符
abccdeshsksgbjhsjhaggsggssg
a(2)
b(2)
c(2)
d(1)
e(1)
g(6)
h(3)
j(2)
k(1)
s(7)