Java implementation counts the number of string occurrences

This article example for everyone to share Java to achieve statistical string occurrence of the specific code, for your reference, the specific content is as follows

Requirements:

A string is entered on the key disk, and the number of times each string appears in the string is required to be counted.

Example: Keyboard entry "aababcabcdabcde"

Output on the console: "a (1) b (4) c (3) d (2) e (1)"

Thoughts:

① Enter a string on the key disk
Create the HashMap set with the key Character and the value Integer
Thirdly, traverse the character application to get every 1 character
4. Take every 1 character as a key to find the corresponding value in HashMap set and see its return value
If the return value is null: indicating that the character does not exist in the HashMap collection, store the character as the key and 1 as the value
If the return value is not null: This means that the character exists in the HashMap collection, add 1 to the value, and then store the character and the paired value again
⑤ Traverse the HashMap set to get keys and values, and splice them according to requirements
⑥ Output result

public class StrCount {
    public static void main(String[] args) {
 
        // Keyboard entry 1 String 
        Scanner sc = new Scanner(System.in);
        System.out.println(" Clear input 1 String string :");
        String line = sc.nextLine();
 
        // Create HashMap Set , The key is Character,  Value is Integer
        HashMap<Character, Integer> map = new HashMap<>();
 
        // Traverse the character application and get every 1 Characters 
        for (int i = 0; i < line.length(); i++) {
            char key = line.charAt(i);
            // Every thing you get 1 Characters as keys to HashMap Collection to find the corresponding value and see its return value 
            Integer value = map.get(key);
 
            if (value == null) {
                // If the return value is null: Indicates that the character is in the HashMap Does not exist in the collection , You use that character as the key, 1 Store as a value 
                map.put(key, 1);
            } else {
                // If the return value is not ull: Indicates that the character is in the HashMap Existence in the collection , Add the value 1, Then re-store the character and the paired value 
                value++;
                map.put(key, value);
            }
        }
 
        // Traversal HashMap Set , Get keys and values, and splice them as required 
        StringBuilder sb = new StringBuilder();
        Set<Character> keySet = map.keySet();
        for (Character key : keySet) {
            Integer value = map.get(key);
            sb.append(key).append("(").append(value).append(")");
        }
 
        // Output result 
        String result = sb.toString();
        System.out.println(result);
 
    }
}

The last traversal output was written with the teacher, but the following one I wrote was not posted because I thought the teacher's one was more in line with the meaning of the question, using splicing, and the results were all the same.

// Traversal HashMap Set , Get keys and values, and splice them as required 
        Set<Character> keySet = map.keySet();
        for (Character key : keySet) {
            Integer value = map.get(key);
            // Output result 
            System.out.print(key + "(" + value + ")");
        }