関連ワード:  java number of characters in string    java number of occurrences in string    java get number of characters in string    java count number of characters in string    java number of occurrences of character in string    java count number of occurrences in string    java find number of occurrences in string    java count number of character occurrences in string    java number of occurrences of substring in string    print number of characters in string java